VAC

World class Valve Amplifiers "Hand Crafted" in the USA.
We Build the World's Finest Audio Components
The reports are in, and VAC electronics took top honours at CES and T.H.E 2014 shows!
 
Writing in Positive Feedback, Myles Astor ranked the VAC / Critical Mass Systems / Focal Grande Utopia EM speakers / Trans Rotor system as the #1 top sound at CES and THE Show. He also ranked the VAC 450 iQ monoblocks as one of the top products he'd like to bring home.

"It is critical in manufacturing perfectionist speakers to use related components that reveal all that's possible; especially in resolution, tonality, dynamics and sound-staging. To this end we've evaluated and tried a vast array of the highest end equipment available. VAC's amplifiers and preamps have turned out to be references of the highest order, and not coincidentally, terrifically enjoyable to listen to."
........ Alon Wolf, owner, Magico Loudspeakers

VAC Introduction

"If it measures good and sounds bad, it is bad; if it measures bad and sounds good, you have measured the wrong thing." - Daniel Von Recklinghausen, former engineer H.H. Scott and editor of JAES

In 1990, after several years of research and development, Kevin M. Hayes left an academic career to start VAC.   He was aided by his father, Channing W.  Hayes, an aerospace engineer who had designed the range tracking system for the first Sparrow missile (using vacuum tubes), circa 1955.  Kevin's driving force was, and is, the desire to experience a more vivid and life-like reproduction of music in the home.

The essence of musical performance is what VAC is all about.  In the art and science of audio, VAC products are masterpieces because they allow each recorded performance to be the masterpiece the musicians intended.

As our quote from the legendary Daniel Von Recklinghausen indicates, subjective musical satisfaction is our primary goal.  We require that all VAC components sound superb and measure at least reasonably well.  Great care is evident in every note sounded by a VAC.  The  first principles' design precepts of VAC's design team are allied to a relentless search for musical accuracy.  For example, more than 1,000 hours of careful listening and experimentation were spent in voicing the critically acclaimed Renaissance Seventy/Seventy.  This same care extends to reliability and customer service. 

An unusual endorsement of the care and quality of VAC products occurred in 1995 when VAC entered into an arrangement with Marantz to resurrect and manufacture the Marantz Classic Model 7, 8B, and 9.  More than 5,600 units of these labor-intensive hand-wired replicas, as well as the all-new Model 66 have been produced by VAC.

VAC components have consistently received the highest praise in publications around the world... Sound and Vision, Hi Fi News & Record Review, Maxim, Audio, Fi, Home Theater Technology, Stereophile, The Absolute Sound, Stereo Sound, Positive Feedback, The Audio Adventure, Ultimate Audio, Bound For Sound, The Sarasota Hearld-Tribune ... even Business Week has featured VAC products, Scientific American has quoted Kevin Hayes on state-of-the-art audio and tubes, and he has appeared on CNN and WRAL-TV.

No discussion of design philosophy and features will prepare you for the sound of these finely crafted instruments.  One listen and you will appreciate that VAC is the world leader in audio entertainment, an appreciation that can only grow over a lifetime of listening.

Where are the "official" reviews? Fact is, VAC hand builds each component in such a labor of love, time intensive way and has enough of a "diehard" following that there is usually an 8-12 week backlog of orders and thus no units available for review. Nor is there anyway to meet higher than current demand from a "great review". VAC is as non-commercial as it gets and the focus is on making the best gear possible, not the best-reviewed gear. Arrange for yourself to hear that the very best tube gear is still made in the USA, one exquisite piece at a time.

Featured

All Products

Reviews

Featured

VA05 PA REN
NZ$ 17,495.00 (incl. GST)
OVERWIEW   The VAC Renaissance Mk III Preamplifier is a development of the preamplifier section from the highly regarded VAC Phi Beta Integrated amplifier and provides balanced and single-...
The first Valve Amplification Company component I ever heard was in the system of a good friend: a...
VA05 PH REN PHON
NZ$ 17,495.00 (incl. GST)
NEW RELEASE - FULL DETAILS FOLLOWING SHORTLYVAC's Kevin Hayes introduced the new Renaissance phono preamplifier at CES 2016 that costs one-fifth as much as the top-of-the-line STATEMENT, which made...
VA10 AP PHI170
NZ$ 17,450.00 (incl. GST)
The VAC iQ is the only system able to hold each output tube’s true underlying idle current perfectly steady at all times, no matter how much you turn up the volume. Say goodbye to manual tweaking,...
VA11 AP SIG200IQ
NZ$ 23,995.00 (incl. GST)
BEST SOUND / CERTIFICATE OF ACCOMPLISHMENT from A/V Showrooms for the VAC system at RMAF 2015 VAC's unique iQ amplifiers are innately intelligent, at least to the point of holding the idle current of...
VAC iQ Continuous Automatic  Bias System ™Class A1 triode input & driver stagesDirect...

All Products

Integrated amplifiers

VA04 IA SIG160
NZ$ 18,995.00 ea (incl. GST)
A TRUE INTEGRATED AMP with HIGH-END LINESTAGE PREAMPLIFIER SECTION.....
SIGMA 160i OPTIONAL EXTRAS:XLR BALANCED OPTION - RRP $1,500M/C PHONO UPGRADE - RRP $1,500SIGMA...
09-10-11: Ghasley Mwilliams, I am the proud owner of a VAC Sigma 160i amp mated to a pair of Wilson...
Integrated amplifiers
VA04 IA SIG160SE
NZ$ 23,995.00 ea (incl. GST)
TRUE INTEGRATED AMP with PROPER LINE STAGE and (optonal) PHONO STAGEThe VAC PHI Sigma 160i - tricle down technology from their flagship seperates result in an integrated tube amplifier that delivers...
SIGMA 160i-SE OPTIONAL EXTRAS:XLR BALANCED OPTION - RRP $2,500M/C PHONO UPGRADE - RRP $3,500GLASS...
09-10-11: Ghasley Mwilliams, I am the proud owner of a VAC Sigma 160i amp mated to a pair of Wilson...
Integrated amplifiers

Preamplifiers & Line-stages

VA05 PA REN
NZ$ 17,495.00 ea (incl. GST)
OVERWIEW   The VAC Renaissance Mk III Preamplifier is a development of the preamplifier section from the highly regarded VAC Phi Beta Integrated amplifier and provides balanced and single-...
The first Valve Amplification Company component I ever heard was in the system of a good friend: a...
VA05 PA REN PH
NZ$ 20,995.00 ea (incl. GST)
OVERVIEWThe VAC Renaissance Mk III Preamplifier is a development of the preamplifier section from the highly regarded VAC Phi Beta Integrated amplifier and provides balanced and single-ended input...
The first Valve Amplification Company component I ever heard was in the system of a good friend: a...
VA06 PA SIG
NZ$ 31,995.00 ea (incl. GST)
Deluxe, fully balanced hand-wired preamplifier with manual signal switching - the culmination of eight years' research and development, this is VAC's finest preamplifier. Its new and unique circuit...
Valves! Who uses this term nowadays?
VA06 PA SIG PH
NZ$ 42,495.00 ea (incl. GST)
Signature MkIIa SE PreamplifierNot long ago, the Signature Mk IIa was the finest preamplifier you could buy. In production since 2000, this enduring classic marked the introduction of the basic,...
I had a wonderful audio moment the other night. It was late in the evening, after a long day. I was...
VA07 PA MAST
NZ$ 43,995.00 ea (incl. GST)
As in the Statement Line Stage, the volume control is a massive custom-made, multisection, 2.2 kg brass volume control with internal brass shielding. Remote-control capability is implemented via a...
Separate PSU Balanced circuit Statement-sourced 2.2kg brass volume ...
VA07 PA MAST PH
NZ$ 64,995.00 ea (incl. GST)
As in the Statement Line Stage, the volume control is a massive custom-made, multisection, 2.2 kg brass volume control with internal brass shielding. Remote-control capability is implemented via a...
◦ Separate PSU ◦ Balanced circuit ◦ Statement-sourced 2.2kg brass volume control ◦ 5 inputs fitted...
VA08 PA STATE
NZ$ 121,995.00 ea (incl. GST)
Mechanical Design The chassis is machined at VAC from high-grade, non-ferrous aluminum and processed through a series of plating steps. The resulting AICuNiCr chassis possesses superior RF rejection...

Phono Stages

VA05 PH REN PHON
NZ$ 17,495.00 ea (incl. GST)
NEW RELEASE - FULL DETAILS FOLLOWING SHORTLYVAC's Kevin Hayes introduced the new Renaissance phono preamplifier at CES 2016 that costs one-fifth as much as the top-of-the-line STATEMENT, which made...
Phono Stages
VA09 PS STATE
NZ$ 129,995.00 ea (incl. GST)
Mechanical Design The chassis is machined at VAC from high-grade, non-ferrous aluminum and processed through a series of plating steps. The resulting AICuNiCr chassis possesses superior RF rejection...
Phono Stages

Power amplifiers (Stereo & Mono)

VA10 AP PHI170
NZ$ 17,450.00 ea (incl. GST)
The VAC iQ is the only system able to hold each output tube’s true underlying idle current perfectly steady at all times, no matter how much you turn up the volume. Say goodbye to manual tweaking,...
VA11 AP SIG200IQ
NZ$ 23,995.00 ea (incl. GST)
BEST SOUND / CERTIFICATE OF ACCOMPLISHMENT from A/V Showrooms for the VAC system at RMAF 2015 VAC's unique iQ amplifiers are innately intelligent, at least to the point of holding the idle current of...
VAC iQ Continuous Automatic  Bias System ™Class A1 triode input & driver stagesDirect...
VA13 AP STAT450S
NZ$ 74,995.00 ea (incl. GST)
The VAC Statement Series amplifiers are designed and manufactured with full devotion to music and absolutely no regard to cost or manufacturing effort. Quite simply, they produce the most...
The sound of the Statement 450 literally caused our jaws to drop. If the Phi 300 is one of the...
VA13 MB STAT450
NZ$ 149,995.01 ea (incl. GST)
Eletrical Design - the hand-wiring approach presented in the Statement 450 far exceeds conventional hand wiring and previous three dimensional techniques. Careful architecture and orientation of...
VA14 MB STAT450I
NZ$ 194,535.00 ea (incl. GST)
The VAC iQ System is the result of 18 years of research and development by the engineers at VAC, and represents the first time in history that each tube in the output stage of a vacuum tube amplifier...

Reviews

......the VAC Renaissance Signature Mk.II is the best preamp I've auditioned. Definitely, very highly recommended.
Brian Damkroger

if the most realistic, most engaging, most mesmerizing re-creation of a musical event is your goal, the VAC Renaissance Signature Mk.II demands an audition. The Signature proved to be one of my "audio epiphanies"—a point where my system moved to a new plane that redefined the intensity of my connection to the music. 

The music hadn't just started, it had come to life. I sat down, mesmerized, and the stress and pressures of the day melted away, replaced with feelings and emotions from other times and places. There was a tinge of the electric excitement that permeates the air before a concert, when the lights dim and the performers take the stage. There was also the simple joy of being swept away by music. But most of what I was feeling, I think, was a lightness and happiness that reminded me of discovering music and audio in college and grad school, a joy that, in the recent frantic weeks and months of swirling logistics, merging families, moving, and endless business travel, had somehow gotten lost. 

The reproduction of dynamic contrasts, like the resolution of detail and tonal nuance, was another area where the VAC's performance was truly special. Most good components reproduce dynamic contrasts evenly and well across the middle range of frequency and loudness. The VAC extended that range from the upper bass to the lower treble, and from the softest pppp whispers to the loudest ffff crescendos. Those subtle, nearly buried countermelodies weren't just wonderfully detailed; their microdynamic shadings were beautifully articulated as well. Every nuance was clear, and seemed much more obvious and dramatic than with other preamps. 

I had a wonderful audio moment the other night. It was late in the evening, after a long day. I was standing in the middle of my makeshift listening room—Trish's dining room—and in spite of the fact that we were moving in just a few weeks, I'd just unpacked and set up my combo and dug a box of LPs out of the stacks in the garage. I cued up Dave Brubeck's Time Out (Columbia/Classic CS 8192), and the first notes of "Blue Rondo à la Turk" froze me in my tracks. 
 
The music hadn't just started, it had come to life. I sat down, mesmerized, and the stress and pressures of the day melted away, replaced with feelings and emotions from other times and places. There was a tinge of the electric excitement that permeates the air before a concert, when the lights dim and the performers take the stage. There was also the simple joy of being swept away by music. But most of what I was feeling, I think, was a lightness and happiness that reminded me of discovering music and audio in college and grad school, a joy that, in the recent frantic weeks and months of swirling logistics, merging families, moving, and endless business travel, had somehow gotten lost. 
 
Aromatherapy is based on the premise that a profound, direct connection exists between the olfactory receptors and the brain—how the smell of new-mown grass, for example, can make us feel the way we did as a child. I occasionally experience the same sort of thing based on my hearing. Sounds—often music, but not always—can take me back to other times and places. Not just remind me of them, but actually re-create the feelings I had. As I've traveled through the world of high-end audio, I've often found that inserting into my system a new, profoundly better component, one that raises the system's performance to a higher plateau, can re-establish this connection, or make it noticeably more direct. In this case, the source was easily identified: the Valve Amplification Company's Renaissance Signature Mk.II preamplifier. 
 
A Renaissance preamp at last! 
The Renaissance Signature was released after six years of development by designer Kevin Hayes. At US$17,000  it was VAC's top model, and the first VAC preamp to bear the "Renaissance" name. Now, the Signature has been extensively updated and become the "Mk.II." The most notable changes between the original Signature and the Mk.II are the use of both input and output coupling transformers in the line stage, and the deletion of the pair of 12AX7 tubes from the line stage, leaving only a pair of 8417 dual-triodes as a differential gain stage, and a pair of 12AU7s as the buffer circuit for the tape output. 
 
The bulk of the design elements that made the original Signature so special remain in place. There are no coupling capacitors in the signal path and no loop negative feedback. The gain stage is fully differential, and consists of direct-heated triodes. On the input side, the Input Selector switch both selects the source and sets the grounding for balanced or unbalanced sources, the latter converted to a differential configuration at the input transformer. 
 
Both balanced (XLR) and unbalanced (RCA) outputs are provided, with a rear-panel selector switch selecting between the two and, again, establishing the appropriate grounding configuration. The output transformer not only converts the differential signal to unbalanced if necessary, but also allows the Signature Mk.II to drive virtually any combination of cable and amplifier inputs. In fact, the VAC's current capabilities are said to rival those of many small class-A1 power amplifiers. 
 
The VAC's phono stage is an unusual configuration, and struck me as a throwback to an earlier time. Through the MM (moving-magnet) inputs, it provides 44dB of gain via a single, fully differential gain stage, implemented via six 12AX7 dual-triode tubes. Through the MC (moving-coil) inputs—and when that rear-panel switch is flipped—rather than increase the gain actively, the switch inserts a pair of wide-bandwidth transformers into the circuit to achieve an additional 20dB of gain. In either case, it uses passive equalization. I did the bulk of my listening using either a Grado Statement or a Benz Micro L04 cartridge, and the MC inputs provided the best mix of detail, depth, texture, and dynamics.
 
The Renaissance Signature looks gorgeous. Its faceplate is a thick, softly sculpted slab of aluminum finished in a flawless, glossy black embedded with gold flecks that beautifully complement the heavy, gold-plated knobs. There are large knobs for Input Selection and Volume, flanked by two smaller ones on each end: Mute and On/Off on the right, Tape Monitor and Cinema/Direct on the left. The Cinema input provides a fixed-gain path from input to output, allowing a user to send the front channels of a home theater or surround system through the main audio circuit, but controlling the level with a processor or A/V preamp. 
The Renaissance Signature's lower chassis, which houses completely separate power supplies for the line and phono stages, mirrors the main unit's shape, size, and cosmetics. Its front panel houses two large, gold-rimmed, backlit meters, which monitor the heater and main, B+, voltages. No scales or numbers are provided, but a dot at the center of the meter's range indicates the proper operating voltage. Both chassis have nifty backlit VAC logos that glow red when the unit is muted, blue during operation. 
 
Listening: Do you believe in magic? 
I've already tipped my hand that, when everything clicks, the VAC Renaissance Signature was capable of truly magical performance. But what exactly was it about this preamp that made it so captivating, and how did it measure up in all of the areas we audiophiles hold dear? 
 
The single most impressive thing about the VAC, and the area where it stood head and shoulders above any other preamp I'd heard, was its resolution. At low levels, whether a single plaintive note fading ephemerally into the surrounding ambience or a subtle countermelody buried deep in the orchestration, the Signature retrieved more tonal, spatial, and temporal information than any other unit I've heard. With the VAC, there was never any question that an orchestral section was composed of multiple instruments, each in a distinct position and each with a characteristic tone, texture, and presence. A lot of top-quality gear reveals this level of detail in the major components of the orchestration, or in the front half of the stage, but where the VAC really stood out was in how well, at lower levels, it reproduced details of instruments buried way down in the mix or at the rear of the stage. 
 
On record after record, subtle countermelodies I'd not even been aware of emerged distinct, detailed, and articulate. The very soft trumpet passages about two-thirds of the way through Saint-Saëns' Bacchanale, from the Paris Conservatoire Orchestra's Ballet Music from the Opera, Anatole Fistoulari conducting (LP, RCA/Classic LSC-2400), were good examples. I might have been dimly aware of their presence before, but with the VAC, the trumpets were distinct, detailed, and tangible instruments, each one richly portrayed and contributing its subtle tonal shadings and phrasings to the multiple countermelodies. 
 
Another example was the soft oboe line shadowing Artur Rubinstein's solo piano through the early portions of his performance of Brahms' Piano Concerto 1, with Fritz Reiner conducting the Chicago Symphony (LP, RCA/Classic LSC-1831). As in the trumpet passages in the Bacchanale, the oboe was not only obvious, but lovingly portrayed, with complex, woody tonal colors and a level of detail that made me think I could hear every expression, every nuance of phrasing and dynamic shading. 
 
The VAC's re-creation of nuance was equally as good—if perhaps not unique—on more prominent components of the orchestration, adding dimensionality to Rubinstein's piano on the Brahms, for example, and additional layers of subtlety to his playing. One thing that stood out was that, with the VAC, the cushion of air surrounding the piano was distinct from and clearly outlined the instrument, rather than the two merging into a single, diffuse image. The effect was to add dimensionality and solidity to the piano, and additional life and realism to the performance. 
 
The VAC's resolution was similarly excellent, though not unusually so, at the loud end of the spectrum. Full-bore orchestral crescendos were appropriately enveloping and overwhelming in their weight and power, without ever losing focus or becoming confused. Midway through the first movement of the Reiner/Chicago reading of Bartók's Concerto for Orchestra (LP, RCA/Classic LSC-1934) the trumpets explode in full-tilt crescendos. Through it all, they retained their unique identities and brassy bite without ever getting overbearing, hard, or edgy. Massed violin crescendos, no matter how intense, remained a coherent group of individual instruments, never becoming hard or steely. 
 
The reproduction of dynamic contrasts, like the resolution of detail and tonal nuance, was another area where the VAC's performance was truly special. Most good components reproduce dynamic contrasts evenly and well across the middle range of frequency and loudness. The VAC extended that range from the upper bass to the lower treble, and from the softest pppp whispers to the loudest ffff crescendos. Those subtle, nearly buried countermelodies weren't just wonderfully detailed; their microdynamic shadings were beautifully articulated as well. Every nuance was clear, and seemed much more obvious and dramatic than with other preamps. 
 
This combination of superb low-level dynamics and incredible resolution of detail resulted in jaw-dropping re-creations of original ambient environments. Halls—their sound, their boundaries, their space—were stunningly portrayed, and much more integrated with the instruments and their surrounding spaces than I'd ever heard before. Once I'd heard the VAC, it became apparent that, typically, only the grossest of ambient cues are reproduced, which leaves things a bit disjointed and incoherent as the level drops. With the VAC, the coherence—the weaving together of the instruments, surrounding air, and the hall itself—was much more complete and much more realistic.
 
Midway through the Saint-Saëns Bacchanale is a delicate exchange between the woodwinds and French horn. With the VAC, it wasn't simply point/counterpoint, but more like a tennis match, the lines bouncing back and forth between the instruments, their location and interaction with the surrounding space and hall boundaries transcribing an arc through the air above the orchestra. This particular passage was especially captivating because the span so beautifully described was truly three-dimensional, traveling not only laterally but also front to back and vertically, describing the relative heights of the instruments as well as their positions on the stage. 
The VAC did an excellent job of soundstage reproduction as well, though no better than most top-quality preamps I've used. Similarly, the VAC was tonally neutral from the upper bass through the lower treble, but not uniquely so. In fact, I've heard gear—the Audio Research Reference 2 preamp and the Sonic Frontiers Power Three amps, for examples—that sounded more neutral than the VAC. In comparison, the VAC sounded slightly soft at the frequency extremes. This was partially due to slightly attenuated dynamic contrasts, which I'll discuss in a bit, but the VAC did sound slightly rolled-off, particularly at the very top. The piccolos in "Dance of the Moorish Slaves," from Verdi's Aida (Ballet Music from the Opera), or the triangles in Bacchanale, were gorgeously detailed and had a beautiful, complex ring, but didn't seem to cut through the air as crisply and cleanly as they should have. Nor did they have the sharp initial transient, or the endless waves of higher and higher overtones emanating outward from their center. 
 
On the bottom end, the VAC's extension was good, with sufficient weight, and double basses, timpani, and bass drums were rich in tonal color and beautifully detailed. But the dynamic contrasts just weren't as large or as sharp as they were from the upper bass through the lower treble. For example, the initial transient of a bass drum, the whooompf, didn't start as sharply or traverse as great a dynamic range as it does in real life—or as it does with some other top-drawer preamps. 
 
One aspect of the VAC's sound that left me scratching my head was its speed, or lack thereof. On one hand, the Signature handled everything I threw at it with agility and aplomb. "Dance of the Moorish Slaves" is a raucous cacophony of sounds, chock-full of fast transients, and the VAC handled it beautifully. And, as I've mentioned above, the scale of the VAC's dynamic contrasts is at least a match for other preamps, except perhaps at the frequency extremes. On the other hand, the Signature just didn't sound as fast as some other preamps I've heard. It left me wondering whether the VAC was softening transients slightly, perhaps due to its use of transformer coupling—or whether the Signature's additional low-level detail and tonal richness were just contributing a greater continuity, and other components might be leaving things just a touch rough around the edges, and thus sounding faster and more abrupt. 
 
One last component of the VAC's sound, and perhaps a reason that some other units can sound more neutral, was its texture. To say that the Signature had a "liquid" texture is too gross. To even compare it to a desert—er, California—afternoon with just a touch of humidity is still overstating it. Think of a cold, crisp mountain dawn. When you've got a handle on that, fast forward to about 11am, when things are just starting to warm up. It's still as crystal-clear as it was at sunup, but everything seems just a bit softer. That's the VAC—just the faintest sort of softening or sweetening. 
 
All of the reference recordings cited here are LPs. Although I had excellent CD players to use, I never found a combination of player and cable that matched the performance I got from the VAC with vinyl, or that revealed the Signature's true glories. This isn't a criticism of its line stage, for it was part of the circuit for vinyl playback as well. If anything, it points out how finely tuned a system must be to really appreciate a component like the VAC, and how carefully associated components must be selected. The choice of interconnect between the VAC and my VTL Ichiban power amps, for example, made a night-and-day difference in the system's sound. Neither the AudioQuest Anaconda nor the Nordost Valhalla—both superb cables—worked at all for that connection, the former sounding slightly opaque, the latter quite forward and two-dimensional. It was only when I installed the Nirvana SX-Ltd. interconnects that the VAC truly sang. Kinda scary, but without the right supporting cast, the Signature was "just another great preamp." 
 
Conclusions 
With the "right supporting cast," the VAC Renanissance Signature Mk.II is the best preamp I've auditioned. Its resolution of low-level spatial, temporal, and timbral detail, and its uncanny coherence across the realms of space, frequency, and loudness, put it in a class by itself. These strengths made listening to a musical performance through the Signature a more moving experience for me, and one step closer to the real thing. 
 
The Signature was not entirely transparent, however. It contributed to the sound a softening and sweetening, however slight, that I heard throughout the frequency spectrum but most clearly at the extremes. 
 
At US$17,000, the Renaissance Signature is expensive, and mercilessly revealing of shortcomings in surrounding components and cables, almost to the point of undue sensitivity. It must be paired with the very best sources and cables to truly shine, and will be appreciated only if followed by truly superb amplification and speakers. All in all, it's not a prospect for the faint of checkbook. 
 
But if the most realistic, most engaging, most mesmerizing re-creation of a musical event is your goal, the VAC Renaissance Signature Mk.II demands an audition. The Signature proved to be one of my "audio epiphanies"—a point where my system moved to a new plane that redefined the intensity of my connection to the music. Unfortunately, such experiences also tend to redefine my expectations of what an audio system—and, ultimately, my checking account—should be able to do. Trish and I are closing on our dream house at the time of writing, and contemplating being house-poor for the next, oh, 20 or 30 years, so this isn't a particularly good time to be contemplating $17,000 preamps. 
 
But where there's a will, there's a way, right? Definitely, very highly recommended.
The Signature Preamplifier Mk 2 is suitable for the most exquisite of audio systems, and thus is recommended without reservation!
Doug Schroder

To me that the Signature II is world-class in terms of shaping the music without distorting the music. Isn’t that what the perfect preamp is supposed to do,  to influence the signal without calling attention to the fact that it is influencing it? This is the only preamp I have used, bar none, which does not in some manner mangle the music by reducing dynamics, veiling detail, portraying a compressed soundstage, or sounding flat. I can see, or shall I say hear, clearly why Kevin Hayes prefers to refer to his creations as instruments as opposed to components. The level of refinement is extreme. The Signature Preamplifier Mk 2 is suitable for the most exquisite of audio systems, and thus is recommended without reservation!

Valves! Who uses this term nowadays?

They are vacuum tubes, or just “tubes”. In the old days before the transistor they were known as valves. Why still refer to them as such? You will have one legitimate reason to use it if the company you own is named Valve Amplification Company.  The mnemonic of the first letters forms “VAC”, as in VACuum tube. In electronics, a thermionic valve is a device used to create or manipulate an electrical signal via the thermal transmission of electrons in a low pressure space. The success of VAC is owed to the functionality and beautiful sound of the electronic valve. 

 
VAC is the vision and passion of Kevin Hayes, who founded the company in 1990 with the practical aid of his father, the late Channing W. Hayes. I never met Hayes the senior in person, but had a few brief, pleasant conversations with him. Even as his health deteriorated, he often manned the phones at VAC. You can gain some insight into the culture of excellence at VAC by reading Kevin’s tribute to him: http://www.vac-amps.com/cwh_tribute.htm.
 
A tribute - that’s what VAC products strike me as, a tribute to audio manufacturing excellence. Everything about the products pulls the mind backward in time to an era when sound, not video, was dominant in leisure time activities. Techno-crazed contemporary culture has undergone revolutions, from the time when printed word was authoritative, to the era when audio was king, giving way eventually to the era of the eyeball. As visual stimulation dominates the entertainment choices of the masses, VAC components are made to give adulation through the art of listening, to showcase the grandeur of the acoustic experience. Showcasing the sharp minds employed in development, excellent build quality from a small production line, and pride of performance and appearance, the Signature Preamplifier Mk 2 (Even the name is prodigious!) is an example of premium American craftsmanship. It is a piece that sits proudly in the finest environments and croons exquisitely, “I am a statement product.”
 
The way the Signature 2 is made certainly makes a statement. It’s designed by what Kevin calls, “first principles” engineering. The goal is not to end up with “mere hi-fi,” but to bring the music back to life. The engineering problem, the design, is broken down into component parts, attention is paid to each stage and all the ways the stages can interact. Emphasis is placed on the dynamic flow of the signal. Kevin likes recalling the words of Daniel von Recklinghuasen, an engineer at H.H. Scott and editor of the Journal of the Audio Engineering Society, “If it measures good and sounds bad, it is bad. If it measures bad and sounds good, you have measured the wrong thing.” I’m in no position to tell Kevin if he’s measured the right thing, but I am in a position to weigh in on sound, and this preamp sounds tremendously good!
 
Better Than A Tool, An Instrument
 
Kevin makes it a point to call his products instruments. There is a huge difference between a tool and an instrument. A tool gets the job done, sometimes quite crudely. An instrument is far more precise, more exacting. My sister is a dental hygienist, and when I visit her for a cleaning she will utilize dental instruments. One called a “root planer” has an elongated razor sharp curved point; think of a miniature Grim Reaper’s scythe with a twist. It’s for poking into the space between the gums and the tooth’s root to scrape plaque off the tooth. You can’t use a toothpick, a rude tool, for such exacting work. You need a honed device made to much more exacting specifications and applied with much more care.
 
When I return home from a visit to my sister’s dental clinic after being subjected to her instruments I run my tongue across my teeth and they feel gloriously clean, natural, and beautiful. Similarly, when I sit in front of the instrument which is called the Signature Preamplifier Mk 2, my ears feel as though they have undergone a cleansing experience. Kevin Hayes is a type of “musical Hygienist, working with exceptionally refined instruments to clear away acoustic plaque from the “teeth” of the music. As the Signature II runs music across my ears they hear something rapturously clean, natural and beautiful. My ears have never felt more pampered.
 
The Finer Points
 
However, before I expound at length about its sound, let us turn our attention to the finer points of this instrument’s construction. When I say finer points of construction, allow me to demonstrate with an example. Much is made nowadays of preamps with hand wiring, and some even tout hard wired connections, of which the Signature 2 also boasts. However, an example of the fanatical devotion to detail and defiant stand against mediocrity is found in the fact that a specific internal wire is chosen for its sonic properties for each section of the signal path. The sourcing of these wires is tightly controlled, such that if the precise wire is not immediately available, even though an alternative might be made to similar specification it will not be accepted as it has an inherently different sound. At times, production has halted for up to eight weeks until the precise wire from the desired manufacturer has been supplied.
 
I do not flinch when considering that method of operations. I conducted extensive tests with entire sets of cables on systems for years. I know what one power cord or one set of interconnects properly placed can do. I often tune systems by the swapping of one or two power cords of silver or copper. If the goal is the supreme transmission of the signal through a highly calibrated system, then substitution of parts is not acceptable. Would another manufacturer, pressed by demands of production, swap out the wire and call it good enough? Possibly, however VAC will not; something to consider the next time you have a statement piece in for repair/upgrade and it takes a while longer than you anticipated, or the fulfillment of your purchase is delayed by a few weeks. You do want the ultimate, don’t you? Kevin will ensure that you will get no less.
 
A preamp such as the Signature 2 should sound about as good as it gets considering the eight years of R&D invested, minimalist signal path, high quality components, zero feedback, and direct-coupled Class A1 triode design. It contains no coupling capacitors from input to output. However, it does have a fully balanced input, as well as outputs.
 
The optional phono stage is also a zero-feedback design using six low-noise twin triodes, and is switchable to accommodate low-output moving coil cartridges. Other phono features include “electrostatic decoupling” to prevent heater circuits from interfering with each other and a separate power transformer dedicated to the phono stage. With the phono stage installed, the two chasses are connected by a second umbilical dedicated for phono. As Kevin states, “It is like having separate components.” The unit I received was outfitted without the phono stage.
 
An aside about the remote control volume, a truly masterful feature described in the Manual as, “…implemented via motorized mechanical devices.” Technically the volume control is a, “motorized multideck potentiometer”. It has two parts, a high quality set of potentiometers and a drive motor, which is responsive to the remote. A common method used in other preamps to obtain remote volume is to use a chip which contains a solid-state buffer and a digital-to-analogue conversion stage. Some companies are putting similar hybrid chips into tube preamps.
 
In contrast to many manufacturers’ use of chip technologies, Kevin considers the “old fashioned” method of mechanically inducing a potentiometer to move to be a superior alternative, with a simpler, purer signal path. According to Kevin, “The potentiometer section is the same sort of part that we would use in a unit without remote control. Ergo, no sonic compromise to gain the remote function.”  In audio I like no-compromise solutions. How many high minded preamps have no remote control, as if the Dawn of the Remote had not yet occurred? I have said it before; I want it all, the sound and the convenience. This is truly the only preamp I’ve used which actually delivers completely in both respects.
 
There is one drawback associated with the volume control, the absence of a clear indication of the listening level. There are no markings to allow the user to “find” precisely the correct level, especially in a case where a previous setting is sought. Instead, the golden cheese wedge shaped volume control’s leading edge points to the approximate unmarked location on the preamp’s face. This is a rather unscientific method of indicating the volume. Some picky listeners will be disgruntled at that lack of certainty. I can think of one instance years ago where I was disgusted with the inability to dial-in accurately two integrated amps as they had nothing to guide me in matching their L/R volume! I am not impressed when aesthetics takes precedence over user-friendliness. I appreciate being given maximum information about a component’s operation, but not at the cost of fidelity. The functionality of the Signature II’s volume control demands the elimination of such displays. Over time I found myself fairly ignoring the dial and letting my ears alone tell me how loud the music should be.
 
Working from the utilitarian, nearly military grade back-side to the elegant front, the unit features a 15A IEC, five sets of RCA and one set of balanced inputs, one set of RCA tape monitor inputs, and one set of RCA “Cinema Bypass” inputs. Two of the sets of inputs are selectable XLR/RCA via a toggle switch, and both the outputs are similarly selectable. The Cinema Bypass has a fixed level and allows use of a high quality surround system with the preamp. The optional MM/MC input for phono can be eschewed for yet another line input. The outputs include two sets of RCA, one set of balanced XLR, and one set of RCA tape output. The tube complement used for the line stage is two 12AU7’s and two 8416’s, while the optional phono stage uses six 12X7. The main line stage uses the Amperex 8416, a premium twin triode “with high trans-conductance, high current capability and low impedance,” according to Kevin. He calls it the clear winner among tubes of this class.
 
As a two-chassis design, note the extra girth at 18” W x 14.5 D, and 5.5” H, the standard 15A IEC is connected to the power supply, and a proprietary umbilical leads to the line stage. The umbilical is long enough that it should be possible to separate the chassis by approximately four to five feet. The slightly oversized CNC machined black powder coated ¼” aluminum casing for both chasses is fronted by a gold flecked faux black marble faceplate. There are no ventilation openings in either case, and the two units never ran hot to the touch even when left on overnight. This might suggest the possibility of installation in a moderately sized cabinet, however I recommend discussion with VAC prior to doing so.
 
There have been two running changes to the volume attenuator over the past nine years. Over that same time period the premium Cardas rhodium RCA jacks were adopted. Earlier in 2009, variable loading was added for the phono equipped models, and the meters were deleted from the power supply. The retro styled meters, similar to McIntosh’s, but with beautiful “VAC Vanilla” colored backlit illumination, remain on my review model, labeled “Audio Supply” and “Heater Supply” indicating the status of the power condition. They look gorgeous but never once budged from their 12 O’clock operating position in the entire review period. If they show the amp is in stasis, then I can see why they would be eliminated; I mean, what good are needles which never move? And if they did move, odds are you would know there was something very wrong with the power supply. However, I sure like retro look and vanilla colored lighting. To my eye they are more tony than the dancing blue meters on the McIntosh Lab MA 6300 Integrated I reviewed. 
 
Elegance To Spare
 
If audio components were solely linked to performance by their appearance, the VAC would be one primo sounding preamp! The enormous gold plated dials and cursive lettering denoting “ Signature Preamplifier”, against the lustrous facade are attention getting! Smaller dials flanking the outside denote “NORMAL/CINEMA” and “SOURCE/TAPE” on the left, with “MUTE” and “ON/OFF POWER” on the right. More central are the golden cheese wedges, the “SOURCE” selector and “VOLUME” dial. In the middle resides the luminous blue VAC logo, complete with the symbol of an electrical bolt - you might say I get a charge out of it! The logo illuminates red upon start up while the unit is muted until warmed up, and once un-muted shows blue. There are two settings to adjust the intensity of the logo’s brightness. I must confess that when the pair of Moscode 402Au amps, with their similar glowing blue Moscode logo arrived, my heart did a bit of a “pitter-patter” from the appearance of these formidable components, their blue beacons of audio excellence beckoning to me. All manner of irrational funding schemes in order to acquire these beauties filled my head merely from the sight of them! I can relate to audiophiles who are so smitten by a component they just have to obtain it!
 
Even an audio dupe can see the VAC preamplifier is serious gear, and everyone who encounters it immediately has the notion that it’s going to sound exquisitely good. As long as the VAC was in my listening room it did not matter what else was on hand, every visitor crooned at its beauty. Beyond appearance, there is elegance to its functionality, the kind of purity that characterizes instruments with dedicated purposes. Monte Blanc fountain pens come to mind as a parallel. In a rebellion against the aesthetically trickled-down-to-the-pavement technological “progress” that seems pervasive, the fountain pen evokes admiration for its beauty and wonder at its audacity. Similarly, the two-channel valve preamplifier is antiquated by the HT world’s standard, but the audacity of the Signature MkII is clear - it looks expensive, it is expensive, but best of all, it sounds as it appears!
 
With The Super-Review System
 
The VAC was a late arrival to the Super-review system I had established in 2008 as a response to the work I was conducting on the Legacy Audio Helix speaker system. This world-class, hybrid, passively crossed speaker had been running with the Ayon Audio CD-3 player, Jeff Rowland MC-606 multi-channel amplifier and a suite of Wire World Silver Eclipse and Silver Electra cables.
 
The Signature 2 did not disappoint. In fact, it lifted the Super-review rig’s performance to new heights. The issue had been the challenges of Class D amplification; I have not yet encountered any Class D amp which has overcome the subtle but pernicious “white” or “dry” sound that strikes my ears as somewhat clinical. I have been in agony over Class D amps, as they produce power to die for; they can perk up the most difficult to drive speakers and make more efficient speakers scintillating. But what is traded away is a mellow, rich sound – a tradeoff I was not willing to accept. I had to get some tubes into the rig to capture the warmth of the sound I was seeking. Rather than pursue other amps I chose to add a tube preamp, the Signature 2.
 
This was an excellent choice, as there are not too many ways one can power six channels of outboard amplification, four channels at 1,000wpc and two at 500wpc, without raising the temperature in the room to Hibachi level! My immediate impression of the Signature 2 is that it has a preternatural sense of having power of its own. In comparison to other preamps, it literally seems to be unfairly advantaged in terms of power. I was not prepared for the “boost” in performance it afforded; the warmth was anticipated and appreciated, but the explosion of the system’s dynamics and scale was such that the system’s already over-the-top power seemed turbocharged.
 
In the movie “Iron Man”, William Downey Jr., as the owner of the world’s largest arms manufacturer, cobbles together a miniature “personal power source”, a generator which aids his survival and escape from terrorists who had wounded him. It held vastly more potential than traditional power sources, and it was the secret behind his “Iron Man”, the fighting suit used in his escape. Indeed, as the suit is continuously refined through design and testing in the lab it becomes the ultimate fighting machine, able to turn the tide of a battle. When Iron man shows up, the war is won.
 
"Careful Matching Not Required”
There are more than one or two refined, powerful processes at work in the belly of the Signature 2. In fact, similar to Iron Man, the preamp is so adept, so powerful, its capabilities so extensive that when it shows up nearly any respectable power amplifier’s performance is elevated dramatically. Reviewers at times issue a caveat with a piece of gear, saying, “Careful matching of (attending) components is required.” In other words, the product is not so easily utilized in wide variety of systems, and can even perform sub-optimally if its weaknesses are not accommodated.
 
Allow me to take a radically different assertion with this review; I assert that the VAC Signature Mk 2 is such a sensational preampthat it is less necessary than normal to painstakingly match components to it. It’s like an electronic Iron man. I can hear the wheels in your mind, “You’d better have good reasons for that logic!” I do. There are considerations which went into the design of the Signature Mk 2 which make it phenomenally flattering of a wide variety of attending components. Here are a few of them: 
 
Class A1 Power Amp  
 
Like Iron Man’s glowing dynamo, the VAC has a powerful secret behind the glowing letters adorning its chassis, a “dynamo” in the form of a class A1 amplifier. Kevin enjoys educating people on the particulars of amp design. When I asked him the implications of the preamp being a Class A1 amp, I received an extended technical explanation as to its virtues. Chief among them are the goals of driving down output impedance and development of prodigious amounts of current.
 
The Signature 2 circuit employs a pair of high current, low impedance triodes operating in class A1 and connected for differential push-pull operation. A wideband output transformer converts voltage into more current and further lowers impedance. This is the same process as in a Class A1 vacuum tube power amp, except that the power requirements are less and there is no encountering loads as low as 8 Ohms. Kevin sates, “The technique confers both low output impedance and the ability to supply large amounts of current, while still being able to provide an excellent voltage swing and, by the design of the output transformer, extend low frequency response.” The influence of the “dynamo effect” with the VAC is quite striking. I was impressed by how the music, any music, was more charged with vitality. It is harsh to say so, but the impression I felt was that it made many other good preamps, both tube and SS sound somewhat lifeless by comparison.
 
Recently I saw a news item which caught my eye – the fact that the human body glows! It seems a very weak light is emitted by the body, if I recall correctly a “radiance” which is on the order of 100 times dimmer than natural light and impossible for us to see with the naked eye. The cause is not known but one hypothesis is that the glow is a byproduct of metabolism. Similarly, the VAC has an “élan vital” to it, a certain something difficult to describe (like 19th century scientists attempting to describe the actual difference between living matter and inanimate objects), but unmistakable when encountered. The Signature II preamp makes the audio system “breathe” in a way most fitting of anthropomorphic description. 
 
300 Ohm Output Load
 
Regarding the Signature 2 having a 300 Ohm output load Kevin notes, “…This is done to provide the circuit with a predictable operating environment… the load presented by any power amplifier is insignificant in comparison... like a single drop of rain in the ocean.” While the description is hyperbolic, I found in practice that it literally could handle with ease any amp I threw at it. As Kevin asserted, it can be partnered with amps having nearly any input impedance. As Kevin relates, “…the performance is the same whether you have a VAC amp with 100,000 Ohm input or a Pass Labs with 5,000 Ohm input impedance.” I used the Signature II with three very different amps, the  Azur 840W (input impedance XLR 38 kΩ; RCA 68 kΩ), the Moscode 402Au (100 kΩ), and the Class D Jeff Rowland 501 Mono Blocks (40 kΩ). Every one excelled in advance of any other configuration in which it was placed (I typically develop no less than three or four systems with each component I review). The VAC lifted each one on its back and carried them all over perceived performance barriers – easily. 
 
Voicing with Radically Different Speakers
fundamental practice at VAC is to minimize the influence of possible shading of the component’s sound due to use of a favored speaker in voicing process. Kevin shares, “…the amplifier designer is in danger of shading his work in a way that complements the speaker’s shortcomings. I term this a ‘complementary error’.” He continues, “Back in the mid-1980’s I remember hearing a mainline tube amplifier sing beautifully on a pair of Martin Logan CLS’s, and fall flat on its face with a pair of Snell A-III’s. Interestingly, I later heard that this company used Quads as their exclusive reference. This experience taught me a lesson.”
 
Consequently, Kevin uses several speakers of distinctly different design in a process he calls “Triangulation”. In order for an improvement to truly be an improvement, it must result in better sound on some or all the speakers and sound worse on none of them. The method obviously works, as not only amps benefit from the Signature 2, but also the variety of speakers I paired with it sounded improved. My experience, without fail, was that just as amps were benefited by the Signature 2, so also speakers benefited. Both the Legacy Audio Focus SE full range floor stander and the Kingsound King full-range ESL sang beautifully with this preamp. These are radically different speakers, and one might think that the VAC might favor one or the other, but indeed, the preamplifier sounded remarkable through both speakers.
 
Putting these and other design parameters together it becomes easier to see that the Signature 2 is far more gracious toward amps and speakers lying outside a narrowly defined range of performance. While other preamps might operate optimally only with compatible devices, the VAC is an instrument made to attain to the pinnacle of performance with nearly any better than average amp or speakers. It accommodates them exceptionally well, and thus makes them perform their best. Like the point guard on the championship team who feeds the crowd favorite power forward, every little maneuver and assist has been worked to make the system’s “power player” stand out and be its best.
 
Some basketball fans obsess about the role of the power forward or center (With an assist from media like the sacrilegious Lebron James Nike commercials portraying him as a basketball messiah), neglecting to tally the innumerable benefits of the point guard. Similarly, audiophiles are tempted to glance past the critical importance of the preamp which sets the stage for the amp to sound impressive. Quite literally, when the Signature 2 was removed from the system with any of these amps the soundstage collapsed, the imaging splayed, the sense of élan vital faded. The music became a lifeless thing instead of an entity with the breath of life in it.
 
Of course, in pursuit of an ultimate rig it would not be recommended to pair such an instrument as the Signature 2 with any old components and speakers; obviously the effort would be made to find commensurate gear. When one takes the time to carefully match the system to the grandeur of the Signature 2, one experiences High Fidelity at its best. However, if you were upgrading to Ultimate Audio status one piece at a time, you would have difficulty doing better than starting with the Signature 2.  
 
Priming The Super-Review System
 
As mentioned previously, I obtained the Signature Preamplifier MkII specifically for use with the Super-review system. Two principle observations emerged:
 
The transparency of tone was stunning, as clear to the ear as crystal is to the eye. The attributes of a diamond, the four “C’s” are clarity, color, cut and carat weight. It is notoriously difficult to determine a diamond’s clarity and transparency apart from a chart, or another diamond. The two other preamps on hand, the Cambridge Audio Azur 840E and the Jeff Rowland Capri, both sounded quite clean in their own right. However, when compared directly to the reference quality Signature 2, both exuded pleasing but distinct colorations and less clarity. This should be expected as the VAC is a price-no-object component; as such it lived up to its reputation for pristine sound. 
It made Class D sound worthy of higher echelon systems. I had used the Channel Islands and Wyred4Sound amps previously, but I preferred the robustness of the Jeff Rowland 501 monos. I worried over the white, or clinical, sound of Class D, however most of it had dissipated with the use of the VAC. The Legacy Helix speaker system reached its peak only with the VAC. As soon as possible, after due comparisons and observations, the VAC remained in the Super-review rig the duration of the Helix’s time with me. In a cost-no-object system in which there was use of Class D amplification I would not want to be without the capabilities of the Signature 2. In fact, as to its performance, I wouldn’t want to be without the Signature II in any cost-no-object system! 
 
Full vs. Flat Sounding
 
The Helix rig was an invitation to revisit classic rock, and I did so with gusto, listening again to the Steve Miller Band, Kansas, Emerson, Lake and Palmer, and the Moody Blues, among others. Hearing ELP leads me to use the term “atmospheric” to describe the impact of the Signature Mk 2 in the rig. On good audio systems the clues as to the size of the space become much more discernible. The preamp plays a critical role in the creation of the sense of fullness to instruments and expansiveness to the venue.
 
One might loosely categorize preamps into two genres, as “Flat” or “Full” sounding. Flat sounding preamps hit all the right notes technically, but struggle to extend the musical notes to the outer perimeter of the recording venue. The notes don’t seem energized and extended to their fullest, like projectiles fired at the walls from a rubber band gun rather than a rifle. Flat sounding preamps don’t re-create the atmosphere of the recording terribly well. The VAC, in contrast, pushes out the soundstage well beyond the vicinity of the instrument. Notes are luminescent, plump with full expression of the physical excitement of a reed or string, and dead on tonally. The very limits of the space are explored intimately. As a result the experience of listening to music with the Signature 2 is that of being immersed far deeper into the sound space than with a flat sounding preamp.
 
An example of this deepening of the experience was found in Spyro Gyra’s Morning Dance, which can suffer the effects of sounding flat, lacking in treble sparkle, bass string snap, and midrange immediacy. In the past I had chalked it up to the age of the recording. However, the Signature 2 surprised me by revitalizing it. I especially take note of music with xylophone, as my grandmother used to play it. When the xylophone is heard on a less than top-notch preamp, the notes of the wooden bars struck with a mallet have no reverberation; they simply “plunk” at the correct pitch and die. However, when heard on the VAC the notes contain reverberation! One can actually hear the woody decay of the note! I thrilled to hear not only gorgeous solidity but also the resonance of the wooden bars as they were hammered.
 
On nearly the opposite end of the spectrum, I also was bowled over by the sound of harmonica as heard through the Signature 2. One of my favorite recordings of the harmonica is Goodbye Blue Sky by Kevin Godley and Lol Creme. The instrument is used in a range extending from bass to treble, and at times with two players acting as a “harmonica section” with solos. “The Last Page of History”, has a particularly rousing rock-blues feel. The Signature 2 entwines but doesn’t lose each slippery note as the players puff into the tiny portals of the instrument while whipping it back and forth across their lips. A special treat is the interplay of each note of the solo harmonica on “Desperate Times” with its anti-note reverberating from the walls of the recording venue. One hears the pitch of the gulp of air indicating the “rest” as the harp is played so powerfully that the emptied lung reflexively fills; there is not time to pull the instrument away from the mouth while continuing the reedy fusillade. In all this, there is no harshness with the harmonica, no edge, no biting shrillness; there is an exceptional amount of glam, without a trace of glare.
 
With The Kingsound King Speakers
 
The Kingsound King speakers have become an authentic joy to me and are one of a handful of rare instruments like the Signature 2 which play waaaaay beyond expectations. When I was forced by paucity of funds to return the Legacy Helix, I despaired that I would never again find speaker satisfaction on a large scale. The King does not have the dynamic force of the Helix, however it brings a similar large, well defined, highly cultivated and coherent sound to my room so capably that your $8k spent on it will reward you as if you had spent $30k.
 
Kevin played a part in my securing the King for review. As VAC components were utilized at CES 2008 to demonstrate the King, he was on hand to discuss them. That is when I learned he owns a pair, and that they were one of the “triangulation” speakers used in the voicing of his Phi 200 amplifiers! He offered that the speakers sounded much improved by replacing the speaker’s 12V wall warts with his own power supplies. I used my own powers of pleading to acquire them for the review. As would be expected, the fingerprints of the master are all over these devices. The King rose from superb to state-of-the-art sound under the influence of the VAC “Royal Power Supply”. That’s pretty much how it goes with VAC gear – whatever it is connected to sounds about as good as it’s going to get!
 
Case in point, helping the VAC to strut its stuff was the pair of Moscode 402Au amplifiers set to Bi-Amp mode. The preamp and amps were a powerful combination, giving me one of the best results from separates I had yet assembled. I discussed in a full review the beefy, well textured sound of the amps. While they sounded more congested with less exotic preamps like the Cambridge Audio Azur 840E, the Signature II opened them up, preventing them from collapsing upon themselves sonically from their own weight. Some of the best bottom-end I have heard in my room was achieved with this pairing. In many instances I have found that use of both tube preamp and tube amp(s) results in a nearly suffocating mellowness, an unacceptable loss of precision and detail. However, the precision I have come to demand in a system was captured by the Signature 2 despite it being a tube preamp.  
 
One of my most beloved and over played pieces from my youth was Emerson, Lake and Palmer’s “Fanfare for the Common Man”. The reverberation of the opening trumpet and tympanis, as well as the throbbing, pulsating electric bass are burned into my psyche. While the Rowland Capri and the Cambridge Audio Azur 840E rendered the trumpet and tympani cleanly, they sounded as though located at the back of an auditorium. However, when the Signature 2 handled this piece, the instruments sounded as though they were strategically located along the street of a city, heralding an event for the citizenry. The echo of the trumpet notes especially had a sense of extending beyond the walls of an enclosed space.
 
A Preamp That Doesn’t Mangle The Music
 
Over the years, one of the reasons I have gravitated toward using the two Pathos Classic One MkIII tube hybrid integrateds as a primary amplification scheme is that it is so pristine sounding. Every preamp that I had used in my system added coloration, detracted from detail, skewed the music ever so slightly – until the Signature Preamplifier Mk 2. It is the only preamp I have used which sounds as clean and refined, but more spacious and audacious, even with mellow sounding tube amps.
 
This says to me that the Signature II is world-class in terms of shaping the music without distorting the music. Isn’t that what the perfect preamp is supposed to do, to influence the signal without calling attention to the fact that it is influencing it? This is the only preamp I have used, bar none, which does not in some manner mangle the music by reducing dynamics, veiling detail, portraying a compressed soundstage, or sounding flat. I can see, or shall I say hear, clearly why Kevin Hayes prefers to refer to his creations as instruments as opposed to components. The level of refinement is extreme. The Signature Preamplifier Mk 2 is suitable for the most exquisite of audio systems, and thus is recommended without reservation!

Manufacturer's Comment:
 
Thank you for the obvious time, care, and passion evident in this review. And, while I know that the intent and purpose is to enlighten readers rather than coddle designers, I would be remiss if I did not note that you have moved me greatly. It is always a humbling experience when a listener "gets" what we have tried to do, when they say, "Yes, that's a good piece of work." We love sound, we love music, and it is our great joy to be able to contribute to and be productive in this field that we love.
 
I am deeply aware that as we reach to higher levels of fidelity, we are able to do so only because we stand on the shoulders of so many pioneers who went before us. They had a hard job, figuring out the basics of how electronics work, developing fundamental circuit topologies, and so forth. As a designer today, I am privileged to study the efforts of great talents like Sid Smith, Saul Marantz, Frank McIntosh, Stu Hegeman, Lincoln Walsh, D.T.N. Williamson, and countless others. I can read their theories, study their efforts, and analyze where they may have been right, and where they may have gone wrong. There is a century long record to be studied and understood. My Dad, whom Doug mentions in the introduction to this review, helped me gain the skills to tackle this. This, coupled with the patience and the ethics he modeled, are about the best legacy any son could hope to have.
 
A friend (and customer) who restores classic studio microphones once observed to me that the instruments we at VAC create will, in a sense, continue to speak for us long after we have gone to our rest. We want that message to be of quality, care, and grace, as they continue to reproduce the emotion, vitality, and breath of life of music for generations to come.
 
Thank you again.
 
Kevin Hayes, President
VAC / Valve Amplification Co.
But of all these preamps, the VAC Renaissance boasts the most impressive combination of serious sound, first-class build, great looks, compatibility with a range of amps, of any model I’ve had in my system. It won’t be leaving any time soon.
Garrett Hongo
Whether as a line stage or as a full-function preamp (both at luxury prices) the VAC Renaissance  nevertheless provides great value in terms of superb quality of sound, exceptional build quality, and versatility of application. Add to this that the Renaissance  is knock-dead gorgeous, and you get a great deal for your money. After nearly two months with it, I have yet to explore all it can do (Cinema bypass, tape loop), nor do I think it has arrived at its own fullness of sound (more burn-in might further improve the phono stage).
 
In the past few years I’ve auditioned a number of different preamps, some for review, some not. A few could be critiqued as being too incisive, too polite, too limited in features, not compatible with a wide enough range of amplifiers. Another few could be considered "serious" in terms of their sound. But of all these preamps, the VAC Renaissance boasts the most impressive combination of serious sound, first-class build, great looks, compatibility with a range of amps, and overall flexibility in its numerous features of any model I’ve yet had in my system. It won’t be leaving any time soon.
The first Valve Amplification Company component I ever heard was in the system of a good friend: a PA-80/80 stereo amp, first made in 1994. He’d invited me over for a listening session with his system, which included Verity Audio Parsifal Encore speakers hooked up to what he called "the VAC." Its looks were retro black with distinctive gold bars and a lightning-bolt logo on the faceplate, and the sound was so gorgeous and involving that I went right to the Internet and bought one used for myself. I still have it -- an old and precious friend.
 
I’ve recently struck up conversations with Kevin Hayes -- VAC’s founder, president, and chief designer -- first on the telephone about replacement output tubes for my PA-80/80 and then at audio shows. When his new Renaissance Mk.3 preamplifier and Phi-200 stereo power amp debuted at the 2008 Rocky Mountain Audio Fest, I asked to review them, and Hayes agreed -- although, famously, it took some time for units to be made available. VAC rarely sends products out for review. My review of the Phi-200 will appear in a future issue of Ultra Audio.
 
Description
 
The VAC Renaissance Mk.3 is a serious piece of kit, loaded with features and attractively designed. It’s available as either a line stage ($9900 USD) or with optional phono stage ($11,900); my review sample was the latter. Its line stage is developed from the preamplifier section of VAC’s Phi Beta integrated amplifier, and the phono stage is trickled down from the circuit topology of the original VAC Signature preamp. But, like descent among the Beauchamps and McCaslins of Faulkner’s Go Down, Moses, these electronic lineages are less straight and direct than entwined and entangled as calabash vines.
 
I suppose, though, that what might first strike someone about the Renaissance is its lavish fit’n’finish. The bling factor of my jet-black review sample also comes in brushed silver jumped out as soon as I got it out of the box and in my rack. The faceplate is a substantial, 10mm-thick piece of machine-beveled aluminum enameled with a luxurious glossy coat of black lacquer embedded with subtle highlights of gold flake. It makes for a striking background for the gold controls -- two large, rakishly beveled, hand-size knobs for the volume and selector on either side of the central VAC logo, which is inset and backlit; and four smaller, outlying knobs: Monitor and Mute on the left, Cinema and Power on the right. Everything about the Renaissance says "high end."
 
The tallish control unit measures 17.9"W x 5.5"H x 15.3"D (including knobs and connectors), and weighs about 25 pounds. The external power supply is an ultralong shoebox 6.75"W x 4.75"H x 14"D and weighing ten pounds. It comes with a 6’ umbilical and a heavy-gauge, cadmium-plated, aluminum-alloy connector clamp you could use as a sap. The chassis of both the control unit and power supply are of nonmagnetic aluminum, chosen for its mechanical and acoustical properties; each made a nice thunk when I rapped it with a knuckle. The remote control is a beefy piece of black-enameled metal with soft-button controls for volume and muting, as well as inoperable buttons for Power and Selector, the latter left over from the Mk.2 (I assume). Both chassis were shipped in a single oversize box, nested in separate foam cutouts. The overall shipping weight is 40 pounds.
 
Inside, the Renaissance is completely hand-wired; all switching is accomplished via mechanical switches with contacts of high-purity silver. Besides deriving the stage circuit topology from the Phi Beta integrated amplifier the change from Mk.2  removed 30 relays from the signal pathways that were necessary for the Mk.2’s more complicated remote control. The line stage has six active circuit elements of twin-triode vacuum tubes (two 12AU7s, four 12AX7s) biased for class-A1 operation, to provide a whopping 22dB of gain. The optional phono stage uses six triodes (three tubes) in its active gain stage, in comparison to the Signature IIa’s 12 triodes (six tubes). The gains are 62dB moving-coil and 42dB moving-magnet, via separate phono inputs selectable via a rear-panel switch. The MC gain is partly accomplished with internal step-up transformers from Lundahl. Via another selector knob on the rear panel, the phono stage also has variable loading: 470, 300, 250, 200, 150, and 100 ohms for MC, and x100 for MM.
 
The rear panel fairly bristles with connectors. From left to right, the top row comprises four sets of main outputs, two RCA and two XLR; five line inputs, those labeled L4 and L5 having both RCA and XLR jacks, and L1 through L3 all RCA; a set of RCA Cine inputs; a Tape loop; a control knob for phono loading; a set of MC phono inputs on RCA jacks (which converts to L6 if not fitted with the phono option); a selector knob for MM/MC; and a set of MM phono inputs (RCA). Below these connectors are mainly switches -- again, from left to right, the umbilical connection, SE/BAL toggle switches (L5 and L4), a three-way toggle switch for the logo (Dim/Off/Bright), and a ground post for the phono cable(s). Though the Mk. 3 is not made with an output transformer, its output impedances are 300 ohms via the RCA jacks and 600 ohms via the XLRs -- low enough, certainly, to drive most any amp, tubed or solid-state. Because the Renaissance Mk.3 has four sets of main outputs, you can readily biamp, either single-ended or balanced. The VAC also inverts phase from all RCA sources, though not from XLR. The connectors are premium Cardas rhodium types that can stand up to the incessant cable swapping reviewers and obsessive audiophiles are wont to make.
 
The Renaissance came with a very good ten-page user’s manual covering cautions, installation procedure and tips, input and output arrays, logo illumination, operation, front-panel and remote controls, tube replacement, and a wise word about tubes in general.
 
Setup and operation
 
Setup was entirely intuitive. I placed the control unit on the second shelf of my rack, just above the bottom one, where my amps reside, then put the power supply on a piece of 3/4"-thick MDF beside the rack and connected the umbilical. To raise it a bit and to improve the bass, image focus, and resolution, I placed HRS Nimbus couplers and spacers under the control unit. I plugged the power supply into my power strip with a 1.5m Cardas Golden Reference power cable, then powered up by turning the Power knob on the lower right of the front panel.
 
The Renaissance mutes at startup. When it clicked on, the VAC logo on the faceplate of the control unit lit up red, indicating the unit was muted. To unmute, I turned the Mute knob at the lower left, and the logo changed from red to blue. Though both chassis got warm during operation, neither was ever hot to the touch.
 
I used both RCA and XLR interconnects between the Renaissance  and four different power amps. The VAC’s phono inputs and two selector knobs, one for MM/MC and the other for loading, were very easy to use. I quickly learned that all three of my phono cartridges preferred the 200-ohm setting, though the audible differences seemed minor. I hooked up two tonearms to the phono stage: my Ortofon RS-309D to the MM inputs and my Tri-Planar VII UII to the MC inputs. I also switched things around sometimes, on occasion moving the Ortofon’s phono cables to the MC inputs and the Tri-Planar’s to a standalone Herron VTPH-2 phono stage, which went into the VAC’s L2 line-stage input.
 
The 22dB gain was so substantial -- I rarely set the volume above 9 o’clock -- that I found myself wishing for a low-gain setting, and even considered replacing two of the four 12AX7s in the line stage with 5751 tubes, which usually have about 30% less gain than standard 12AX7s. There was nothing wrong or off-kilter with what’s called the "taper" or linear sweep of the gain, the VAC maintaining linearity from about 8 to 11 o’clock -- and above that I dared not go! I just found myself wishing for a longer sweep and finer control over the gain settings.
 
The VAC Renaissance Mk.3 worked well with five different power amplifiers, four of them tubed: my reference deHavilland KE50A monoblocks, the VAC PA-80/80, my Herron M1 solid-state monoblocks, an EAR 890 stereo amp (reviewed in July), and VAC’s Phi-200 stereo amp (review forthcoming). Perhaps due to its relatively low output impedances (300 ohms via RCAs, 600 via XLRs), the VAC demonstrated a sonic integrity no matter which amp it drove, producing both richness and resolution while still allowing the individual character of the amp to come through. What follows, though, are my impressions of how the VAC worked with my reference amps, the deHavilland KE50A tubed monoblocks.
 
Listening: line stage
 
From the very start, with no break-in of the Renaissance line stage, I was knocked out by the sound my system made with digital recordings. My listening notes are full of raves and exclamation points -- and things got only better throughout my listening sessions. The line stage’s characteristic sound was rich and fulsome, with great momentum and tonal weight, yet also with openness in the highs, and great finesse handling complex passages at high volumes, as in orchestral climaxes. I found the preamp nimble and stout, with capabilities that gave my system tonal dexterity and harmonic saturation with small acoustic ensembles, raunch and slam with amplified rock groups, and dynamic range and a formidably broad palette of expressive tonal colors with large orchestras, solo operatic singers, and Renaissance choirs. It seemed there was nothing the VAC’s line stage wasn’t good at. Silences were appropriately black, and when I placed an ear close to the speaker drivers, I heard no "tube rush."
 
Beginning with solo acoustic piano music, I played the first half of Shura Cherkassky’s The Complete HMV Stereo Recordings (two CDs, First Hand Records Remasters HMR04). In the Bach-Busoni Chaconne, the piano’s rich, deep bass notes seemed to rise from out of my floor. There were crisply played yet mellow-sounding, buttery midrange chords, ringing trebles rich in harmonics and resonance, and the sound was so "live" I thought I could feel the pressure on the piano’s soundboard. The VAC was exquisitely precise in shaping all critical aspects of piano sound: attack, sustain, decay, and the overall bloom and shape of the notes as they formed, blossomed, and lofted away in a trail of harmonics evaporating in air.
 
Then I tried electric blues -- Fleetwood Mac’s Mr. Wonderful (CD, Rewind/Columbia 474612-2). The sound on the original 1968 Blue Horizon LP is raw, lively, and visceral, with a big dose of unmistakably electrified air in its studio ambience. On CD, via the Renaissance Mk.3, the sound was, if anything, more raw and lively. "Rollin’ Man" had Mick Fleetwood’s brisk snare-shuffling and floppy tom-tomming behind Peter Green’s characteristically thinnish tenor lead vocal. The four-horn choruses of doubled alto and tenor saxes (led by Johnny Almond) made for both swelling backup fills to Green’s somewhat nasal singing, and punchy counterpoints to his lead guitar. There was a ferocious bite and satisfying squawk to Green’s Les Paul Gibson Custom on his extended solo, the treble and sustain both turned way up and the bass turned halfway down -- a sound favored by the Chicago bluesmen who inspired this music. That the VAC could render this sound while adding no sophistication or mellowness is a testament to its versatility and, for lack of a better word, transparency.
 
For a test of rhythmic agility and the textural complexity of blending and separating numerous acoustic instruments, I played Sublime Illusion, by Eliades Ochoa y El Quarteto Patria (CD, Higher Octave World 47494). "Saludo compay," a Dominican son, begins with Ochoa’s introduction on 12-string guitar in his distinctive style. Silky strings were strummed and plucked, with a rapping conga accompaniment giving way to a lovely brass chorus with trumpets played in unison, sounding bright, punchy, and precisely timed, and throwing off harmonic trails that fell deftly in rhythm with the syncopated dance beat. Ochoa’s voice then took up the lead, rough and a little dry, supported by a quatro bass and followed by a chorus of singers, each timbrally distinct in their cries, shouts, and yips. I heard claves, a guiro scratched in rhythm, percolating maracas, and the tink-tank of cowbells over congas and bongos. The VAC sorted out this rich, highly articulated, rhythmic tapestry of distinct sounds like St. Peter processing a cloud of new arrivals at Heaven’s gate. The soundstage extended just beyond the speakers, with a nice depth and fine instrumental imaging. The exceptionally clean sound made starkly apparent the timbral differences during instrumental solos and full-combo passages, demonstrating the VAC’s exceptional powers of resolution.
 
But it was with classical music that the VAC excelled and especially impressed, from recordings of small ensembles and chamber orchestras to full symphony orchestras. For a real workout, I played a recording of Dvorák’s Cello Concerto by soloist Pieter Wispelwey, with Iván Fischer conducting the Budapest Festival Orchestra (SACD/CD, Channel Classics CCS SA 25807). Aside from the warmth of Wispelwey’s cello, what struck me was the generous depth of the orchestra and the dimensionally organic manner in which notes, solos, and whole sections playing in unison came forward through complex layerings and timing of the music in the soundstage. I heard French horns from the orchestra’s deep rear emerge into the thematic from behind the viola and cello sections, performing a plangent, clear, yet subdued echo. Crescendos came briskly and authoritatively, with fine, separable body in the woodwinds and bass viols. And in Wispelwey’s solo passages I could hear his bow bouncing, feel the resonance from his cello’s body, and easily follow the sinuous melodic lines he draws through a sprightly dance passage or a mordant, robust one. The orchestra’s sound is full of dynamic dramas, relentless accelerandos, and thrilling tuttis, the VAC rendering all of these with proper bass weight and clear high notes from the violins and woodwinds. At the concerto’s climax, brassy fanfares added yet another sonic layer of pleasure and complexity. The VAC never collapsed its soundstage, never lost the separable sounds of the instruments and sections in a confused hash at crescendos, but maintained a superb clarity and tonal sophistication throughout this work, which is so demanding of an audio system’s capabilities.
 
The VAC’s tonal qualities allowed me to resurrect more than three dozen CDs I’d banished to the dungeon of my collection -- those I’d judged thin, shrieky, washed-out, and unlistenable. Most got back into heavy rotation here: Cantatas & Masses, a set of J.S. Bach’s choral music sung by Collegium Vocale with a baroque orchestra (Virgin 5 62252 2); Grigory Sokolov performing solo-piano music (Naïve 09861 30421); numerous recital CDs of Handel arias for soprano; several collections of Renaissance choral music; and even a few XRCDs and hybrids of orchestral music. I was so delighted, and yet perplexed, I called Kevin Hayes and asked why this was so. Was it the VAC’s relative low impedance vs. the impedances of the various power amps? (These recordings sounded better no matter which amp or amps I used.) Was it the relatively high, 22dB gain of the Renaissance Mk.3 itself? Was it VAC voodoo? Basically, Hayes said it was "voicing," a process of perfecting the preamp’s sound by ear in the shop before it was sent out -- voicing, that is, by Hayes’s own, well-tutored ear.
 
Listening: phono stage
 
At first, there was a quite audible difference between the Renaissance MM and MC sections. While MM sounded great right off the bat, amplifying a 3.0mV signal from my Ortofon SPU Mono GM Mk.II cartridge and playing any number of vintage and reissue mono jazz LPs, the MC section took some time to break in. Playing stereo LPs and using the 0.24mV-output Zyx Airy 3 cartridge on my Tri-Planar VII UII tonearm, the MC section sounded hashy on orchestral crescendos, strident on violins and horn fanfares. I called a friend familiar with step-ups, and he recommended I get hold of Granite Audio’s Phono Burn-In and RIAA Test CD (101.1) from Music Direct ($35 plus shipping). I used it to send signals from the RCA outputs of my Cary 303/300 to the inputs of the VAC’s MC phono section, running it in for about 70 hours over the course of five days and nights, in addition to the 30 or so hours I’d already run it playing LPs.
 
After that, there was a new openness in the highs, the grain had dropped out of the upper mids. Overall, the MC section had become completely musical and organic in the midrange, much less "electronic" in the highs. It had "touch," as basketball players say of a finesse jumper: a smooth shot.
 
I played Ravel’s Boléro, performed by the Los Angeles Philharmonic Orchestra conducted by Zubin Mehta (LP, London CS7132), a tour de force of a single long crescendo of 14 minutes, from pp to fff, famous and agonizingly slow, its insistent theme repeated again and again until the piece ends in a thunderous climax. What makes Boléro compelling throughout is how the theme is taken up by various instruments in succession, demonstrating a variety of achingly glorious timbres and exotic performance flourishes on this vaguely Oriental melody. As an undercurrent, the incessant, march-like bolero rhythm is played on a snare drum, with staccato accompaniment of trumpets and occasional rousing accents from the horns, bassoons, and timpani. The VAC captured the piece’s feeling of an ornate, equestrian processional, medieval and military, as though emerging from a near horizon, then gradually approaching to eventually fill the immediate foreground with musical pageantry as the entire parade, muscular and disciplined, tramps by mere inches away. By degrees throughout the whole piece, the snare increases in volume from pianissimo to a rattling immediacy, joined at the climax by a second snare, their duet accentuated by braying fanfares and explosive thumps from the bass drum. The VAC rendered the drums, woodwinds, brass, and bass and midrange strings at first with precision and grace, then with growing forcefulness and unmistakable authority. Almost every sound, whether loud or soft, sounded clear and precisely timed. My only complaint was, again, with the violins -- the sound lacked that higher level of finesse and clarity I’ve heard from the best standalone phono stages.
 
But what a midrange! On combo jazz LPs, the VAC’s MC section, in combination with either the Zyx Airy 3 cartridge and Tri-Planar tonearm or the Ortofon Anniversary SPU with Ortofon RS-309D arm, was nothing less than superb.
 
Tracked by the Ortofon Anniversary SPU, a seemingly old-school stereo pickup and headshell made with entirely new-school laser technology, Ben Webster and Associates (180gm LP, Verve/Speakers Corner MF VS-6056) sounded not merely lovely but astonishing. The live sound of the entire LP knocked me out. Ray Brown’s bass improvisation on "In a Mellow Tone" was upfront and so microdynamically detailed that I stood up from my listening seat and felt like yelling. Leslie Spann’s softly amped electric guitar was no less present and tasty in nuance. Finally, Webster’s tenor sax achieved such a burnished, enveloping tone on his solo, full of sashaying rhythms and sophisticated slides and syncopations, that I raised my palms in praise. Not to mention the percussive sweetness of Roy Eldridge’s muted trumpet! The VAC presented every instrument to scale across a soundstage a bit wider than the spread of my speakers, with liquid, nearly holographic images.
 
Comparison
 
My reference line stage is the deHavilland Mercury 3, which has a gain of 12dB and an output impedance of 1k ohm -- fairly normal for a cathode-follower preamp. At US$4495 (with remote), its cost is about half the VAC Renaissance Mk.3’s. It also has 10dB less gain, three times the output impedance, and represents a different approach to circuits and sound. When I played the same CDs on my Cary 303/300 and used the same Cardas Clear interconnects from CD player to preamp, the Mercury 3 had a lighter sound than the VAC, with less tonal density in the midrange, but more airiness and nuance in the highs. Not as rich with jazz saxophone or orchestral strings, it’s perhaps perfect for operatic voices and Renaissance choral music.
 
The VAC Renaissance by contrast, excelled at combo jazz, blues and rock, and orchestral music. It produced a much more weighty and tonally dense sound, yet wasn’t without its own sparkle and openness in the highs, as well as great bass slam and control. With soprano recital and Renaissance choral CDs, the VAC was less refined than the Mercury. With digital recordings, such as Chanticleer’s of Byrd’s Missa in tempore Paschali (CD, Harmonia Mundi HMC 905182), there was more air and ambience to the polyphonal choral singing with the deHavilland pre -- but more density, drive, weight, and slam through the VAC with, say, Wispelwey’s Dvorák Cello Concerto. Finally, the VAC played numerous CDs that sounded thin, hashy, or washed out via the Mercury 3, showing that it could dig a richer sound from the same signal. And it livened up many others, particularly jazz, folk, and rock CDs.
 
The VAC’s MM section was marvelous -- rich, textured, and organic with mono jazz LPs such as Duke Ellington and His Orchestra’s Ellington Indigos (Columbia CL 1085). The MC step-up worked wonderfully with jazz, and very well with orchestral stereo LPs too, producing an analog sound even better than its digital sound. However, as I hinted in my comments on the Mehta-LAPO recording of Ravel’s Boléro, it lacked the airiness, resolution, and harmonic refinement produced by my reference, the Herron VTPH-2 active phono stage ($3650), hooked up to either the Mercury 3 line stage or a line input of the Renaissance Mk.3 itself -- the latter a combination I adored.
 
Conclusion
 
Whether as a line stage or as a full-function preamp (both at luxury prices) the VAC Renaissance  nevertheless provides great value in terms of superb quality of sound, exceptional build quality, and versatility of application. Add to this that the Renaissance  is knock-dead gorgeous, and you get a great deal for your money. After nearly two months with it, I have yet to explore all it can do (Cinema bypass, tape loop), nor do I think it has arrived at its own fullness of sound (more burn-in might further improve the phono stage).
 
In the past few years I’ve auditioned a number of different preamps, some for review, some not. A few could be critiqued as being too incisive, too polite, too limited in features, not compatible with a wide enough range of amplifiers. Another few could be considered "serious" in terms of their sound. But of all these preamps, the VAC Renaissance boasts the most impressive combination of serious sound, first-class build, great looks, compatibility with a range of amps, and overall flexibility in its numerous features of any model I’ve yet had in my system. It won’t be leaving any time soon.
 
. . . Garrett Hongo
the Phi 200 proved superior in resolution, inner detail, imaging, soundstaging, speed, and pace, rhythm, and timing (PRaT). Its top-end and midrange definition, articulation, and dynamics were amazing.
. . . Garrett Hongo

 From the start, the Phi 200 exhibited terrific dynamism and extension, an unmistakable speediness, and tightly focused imaging. The "jump factor" was tremendous. The VAC's timing was especially notable: cues and attack transients from tight studio bands, orchestras, and chamber musicians fell not blithely into place, but sprang from the speakers like panthers quick and lithe.  

Kevin Hayes has come up with something very special in the Phi 200: a tubed stereo amplifier with the speed, grip, and top-end extension of solid-state, yet with the flow, sparkle, and treble sweetness of tubes. At its listed retail price it's a serious high-end investment, but it deserves to be considered by anyone who's interested in the cutting edge of audio engineering. It's a cliché to say that the sounds of the best tubed and solid-state electronics are now closer to each other than ever before, especially if those sounds have lost something of the magic of vintage gear, but the VAC Phi 200 has a magic all its own -- there's a commanding ghost in this machine that sings clearly, cleanly, and with potent vitality. 

Recent Western literary theory makes a distinction between the author of a book and its writer. The author is the ephemeral entity conjured as the consciousness within a given work -- a novel, say -- while its writer is the actual person who wrote it. The essential difference is that the writer has a life outside the scope of the book -- s/he eats, sleeps, messes around, plays with stereos, etc. The author resides only in the work itself, spectrally, a being conjured by the words of the text -- limited in existence, only a voice or a presence behind the words. There might be a parallel to this in hi-fi: an audio component not only has its "writer" -- the designer who goes on living life, designing other components, showing up at Consumer Electronics Shows, racing balloons in Kansas, shredding the break on the Inside Reef at Makaha -- but also its "author," the virtual voice within the machine. 
 
In this sense, the "writer" of the Valve Amplification Company is Kevin Hayes, president and chief designer of fine audio electronics since VAC's inception. I have met Hayes, exchanged jokes with him at audio shows, and spoken at length with him on the phone. He is definitely a personage. And yet, each VAC component has also its "author," a specific character conjured in the sound of the individual piece of gear itself, a kind of spirit in the sound. If we apply this philosophic notion of split entities to audio, it runs counter to the traditional audiophile view that identifies a particular "house sound" throughout a given line of electronics, insisting that all components produced by a company share, by design, a common character. 
 
My own thinking about VAC electronics had ascribed to them a shared house sound, a constancy of voice (or single authorial presence) that was warm, somewhat sumptuous, and emphasized sensuousness over precision. But to my ears, the Phi 200 stereo amplifier ($9990 USD) is something quite distinct from this. It breaks with my own prior assumptions about any "house" sound VAC gear might be said to possess. 
 
The description of the Phi line of amps on VAC's website boldly compares their sound with that normally associated with solid-state: "The Phi amplifiers produce the areas of beauty typically associated with good vacuum tube designs, but also go well beyond this, producing bass impact, speed, and dynamics that have converted many adherents of solid-state design." And, a bit further down the page: "You will hear the punch and control normally associated with solid-state amplifiers. . . ." 
 
I heartily agree. Kevin Hayes has created something startling in the Phi 200, his latest tubed amplifier. The authorial voice that emerges from it produces a quality of precision -- in imaging, microdetail, microdynamics, transient speed, treble extension, and bass grip, all within a generous soundstage -- that many think is possible only with solid-state designs. This ain't your Daddy's Oldsmobile, people. 
 
Description 
 
The Phi 200 is a 100Wpc power amplifier with speaker taps for loads of 1-2, 2-4, and 4-8 ohms. Its tube complement consists of four KT88s and four 6SN7s. Though it can be easily converted for use as a 200W monoblock via a mode switch on the rear panel, I never used it that way. Fully balanced in its circuitry, the Phi 200 has both XLR and RCA input modes, and its gains are a claimed 36dB single-ended or 30dB balanced. The input and driver stages are the class-A, direct-coupled, low-mu triode circuits originally developed for VAC's Phi 300 amp (150Wpc). The bandwidth claims are impressive: 13Hz-70kHz power bandwidth and a frequency response of 4Hz-75kHz. 
 
The Phi 200 is large -- 17.8"W x 8.75"H x 17.8"D -- and weighs 90 pounds. Most of its weight is in the rear, where the massive, custom-wound transformers are mounted. The nonmagnetic chassis is 2.4mm thick and comes in an impressive black powdercoat. The 9mm-thick faceplate comes in black lacquer with gold flecks, or silver lacquer with the chassis in contrasting black powdercoat. The VAC logo, on a handsome piece of recessed glass on the front panel, is backlit in blue when the amp is switched on. All in all, the look is clean, post-utilitarian, and very attractive.
 
Design 
 
The Phi 200, introduced at the 2008 Rocky Mountain Audio Fest, was developed from the Phi 300 stereo amplifier (now the Phi 300.1a in current iteration), which Kevin Hayes had created in 2006. "It brings the Phi technology to a price point accessible to more people," he told me by phone. 
 
When I asked what the Phi technology is, precisely, Hayes explained that it’s a new front-end and driver-circuit topology he'd developed from the high-mu paraphase circuit employed in his first amps, the PA-45 and PA-90 monoblocks from 1990. Paraphase refers to the type of phase inverter used in the front-end with single-ended signals, and differs from the Williamson front-end circuit used in VAC's PA-80/80 and PA-100/100 stereo amps from later in the '90s. Whereas the Williamson front-end circuit used a "cathodyne" phase splitter that is capacitively coupled to the driver, and the paraphase circuit in the earliest VAC amps used high-mu triodes, also capacitively coupled to the driver stage, the new Phi paraphase circuit uses low-mu triodes at the input and driver stages and eliminates the capacitors for direct coupling to the drivers. In balanced mode, there are no coupling capacitors in the input and driver stages, and, even in single-ended mode, the input circuit has only a "half-capacitive" stage -- still fairly direct, compared to earlier VAC designs. 
 
What this means for the listener, Hayes said, is that Phi amps are much faster than VAC's first paraphase mono amps and Williamson-derived stereo amps, and hopefully produce more vividness and energy without giving up anything in terms of liquidity, nuance, and soundstaging. 
 
What Hayes didn't expect was an improvement in bass performance. "Some hear a distinct increase of bass control and articulation," he said. But what was most interesting was that the new Phi circuits didn't change the basic match between the output stage and the speakers, where many have assumed tube amps lose their grip on the bass. "It is assumed that the damping factor has to be high," Hayes explained, "but the new circuit in the Phi 300 (and subsequent 300.1 and 300.1a) and Phi 200 didn't change the damping factor one bit." 
 
Hmmmm, I thought. O brave new world that has such amps in't! 
 
Setup and operation 
 
The Phi 200 arrived in a large (24.5" x 12.75" x 13"), sturdy cardboard box, nested top and bottom in thick, fitted blocks of urethane foam. Inside were eight boxed vacuum tubes -- four Shuguang KT88-SCs and four Shuguang 6SN7s -- each tested by VAC and carefully labeled for a corresponding socket position on the amp's top deck (even the center pins of the power tubes are so marked). In a nice touch, the amp's faceplate was covered in a soft polishing cloth held in place by a cat's cradle of rubber bands. There were also a stock power cord (which I did not use), a yellow ochre plastic bias tool (marked Vishay Spectrol), and an 8.5" x 11", 15-page owner's manual that meticulously describes setup, tube position, and operation. The warranty is two years, parts and labor, excluding tubes. 
 
I seated the tubes in their sockets, carefully matching each to its designated position on the chassis, then hooked up the cables. The Phi 200's connectors are mounted on the top of the chassis at the rear, along a narrow shelf behind the power and output transformers. This proved very convenient for attaching the spades of my speaker wires and RCA and XLR interconnects (I alternated my use of the latter). 
 
Biasing the tubes was a cinch -- the bias lights are in a row behind the output tubes, and each glows red or orange or green, depending on the setting. With the amp on and no music playing, you insert the blade of the bias tool (or a very thin-bladed, flathead screwdriver) in the numbered hole in the chassis that corresponds to a particular tube, fit it into the slot in the head of the bias screw inside that hole, and turn the screw. The bias light will go from red through orange; when it has just turned green, the setting is correct. The procedure was familiar to me; it's pretty much been the bias routine for VAC amps for over 15 years. 
 
Switching from balanced to single-ended operation is similarly easy. Each channel has a set switch just to the side of each input tube. The forward setting is labeled Singled Ended, the rear setting Balanced. Just make sure both channels are set correctly and you're good to go. The VAC Phi 200 is turned on and off with a switch on the right of the faceplate -- much more convenient than amps with power switches on the back! Finally, the Phi 200 does not invert absolute phase. 
 
Throughout the review period I used various combinations of cables, including a couple of very reputable, high-end brands, and both XLR and RCA interconnects, before settling on my reference Verbatim speaker cables, Verbatim RCA interconnects, and Cardas Golden Reference AC cord. I also tried two different preamplifiers: a deHavilland Mercury 3 and a VAC Renaissance 3. The Phi 200 sounded best run single-ended via its 4-8-ohm taps (my Von Schweikert VR5 HSE speakers are rated at 91dB and 6 ohms). It performed very well with both preamps, though most of my listening was done with the VAC Renaissance 3. With the stock and various NOS input and driver tubes I tried, in both balanced and single-ended modes, the amp operated smoothly and without a hitch throughout the review period. Break-in did seem to take a while, likely due to the transformers needing serious run-in before they settled. I ran the amp for over 200 hours before taking any listening notes. 
 
Sound 
 
From the start, the Phi 200 exhibited terrific dynamism and extension, an unmistakable speediness, and tightly focused imaging. The "jump factor" was tremendous. The VAC's timing was especially notable: cues and attack transients from tight studio bands, orchestras, and chamber musicians fell not blithely into place, but sprang from the speakers like panthers quick and lithe. 
 
The imaging, speed, and soundstaging were spectacular with "Smooth," from Carlos Santana's Supernatural (CD, Arista 07822-19080-2). Instruments extended far into the room, my speakers disappeared, and the band was spread horizontally across a wide soundstage as Rob Thomas's electronically manipulated and sometimes deliberately artificially dry voice dodged annoyingly here and there in the soundfield. Other than that studio trick, the sound was clear and extremely liquid, the Phi 200 providing the best soundstage I've ever heard in my smallish (12'W x 16'L x 8.5'H) listening room. The sound was also extraordinarily clean, with each instrument in its own defined airspace. These aren't things I usually crave in my listening, but I had to take notice of every excellence provided by the Phi 200: clear, sometimes crystalline timbres in the highs, tremendous drive and detail, and lots of timbral separation among instruments. "Like solid-state," my notes say, "but with more liquidity, more sensuousness note to note" -- and yet no tubey warmth, confirming almost completely the claims made on VAC's webpage. 
 
From Eric Clapton's famous Unplugged (CD, Reprise 45024-2) I got consistently tight bass, great pitch definition, and a supremely clean sound. My notes: "Clarity, clarity, clarity." From my usual electronics I heard greatly improved transient snap, microdynamics, and drive. Voices and instruments were more sharply defined, and small details I hadn't heard before, such as the squeak of fingers on wound guitar strings, popped in and out of the mix. Female backing vocals, the buzz of Clapton's bottle slide on the steel-wound strings, and the soft whump of a washtub bass -- all bubbled sweetly into the soundfield. 
 
Conventionally, you'd think that a sound as detailed as I'm writing about would have produced an overall impression of an "analytical," even a clinical sound, but that was far from the case -- what resulted was an even stronger connection to the music. I must have listened to "Tears in Heaven" over a hundred times through various systems over the years, but hearing it with the Phi 200, all the nuances -- Clapton's marvelously percussive nylon-stringed guitar intertwining as intricately as bougainvillea on a bamboo lattice with Andy Fairweather Low's tasteful accompaniment on his own nylon-stringed guitar, Chuck Leavell's mournful synthesizer, Nathan East's tasteful and at times melodic plucking of the bass, the subtle background singing of Katie Kissoon and Tessa Niles, the regret-tinged timbre of Clapton's lead vocal -- came together in what seemed a performance as close to "live" as I've ever heard. This noble dirge of a song, its humble prayer, and its tragic story affected me as never before. It was emotional. 
 
But in those first few weeks I also struggled to sort the character of the Phi 200 from what turned out to be high-frequency distortion picked up somewhere and amplified by the system. The highs in classical music and female voices seemed peakish, even edgy at times, and violins and soprano voices were often oddly ragged. I heard a top-end tizz -- a very fine hash -- that translated into a kind of grit in the treble range. Trying a few different cabling combinations revealed the problem to be one of airborne vibration. My right speaker is right next to my audio rack, and the tops of the CD player and preamp naturally pick up a lot of airborne energy. This normally isn't a problem with my reference monoblock amps, the tubed deHavilland KE50As, or other amps, but the Phi 200 moved so much more air, proved so dynamic and fulsome in top-end extension, that it energized my listening room to the point that I heard problems. 
 
At first, I placed a few ziplock bags filled with rice -- my do-it-myself damping pillows -- atop the preamp. This did the trick, however inelegantly. Later, via Audiogon, I discovered some handsome dampers of solid brass made by edenSound. These chamfered discs, called FatBoys ($39 each), are 3" in diameter and about 1" tall, with Elastomer on the contact end to protect your gear, and completely calmed the excess energy on the preamp chassis. I continued to use the bags of rice on my CD player, and eventually tucked them inside some black cotton Tibetan shoulder purses ($7 each) I found at my local singing-bowl store. I liked that they were decorated with the mandala of the I Ching. 
 
Those problems solved, the Phi 200 provided such tremendous clarity that it made me curious about period instruments and the rapid vocal ornamentations in music from the Italian Baroque, particularly the compositions of Vivaldi. I wanted to pit the amp's speed against its clarity, its ability to keep up with virtuosic performances on multiple instruments, their harmonies and distinct timbres, and hear if it could reproduce these without losing significant detail and thus becoming more impressionistic than precise. 
 
I played several different Vivaldi recordings in my collection -- Fabio Biondi and Europa Galante, the Venice Baroque Orchestra with Giuliano Carmignola, Rachel Podger's La Stravaganza, and several of the operas -- but in the end focused on soprano Sandrine Piau's In Furore: Laudite Pueri e Concerti Sacri, with the Accademia Bizantina directed by Ottavio Donatone (CD, Naïve OP 30416), particularly Vivaldi's motet In furore iustissimae irae for soprano, two violins, and viola e basso. The Phi 200 proved superb with period strings, rendering a fast, clean sound without glare, etch, or that notorious sourness that many complain such instruments have when played without vibrato. The amp captured all the vivaciousness and warp speed of play of the baroque ensemble. Especially satisfying were the overtones and harmonics of the instruments being woven together in an involving musical tapestry. I was able to consider the complexities of tone not only of each instrument, but also the superadded richness of tonalities and drive that emerged from each thematic run of the ensemble's playing. And Piau's singing in the closing Alleluia was a combination of percussive, pulsating trilling and gorgeously rapid roulades. As a test of the amp's agility, speed, and timbral accuracy, Vivaldi and a virtuosic soprano presented no problem. 
 
But for all the pleasures of the Phi 200's speed and accuracy, I wondered about midrange sweetness, and a kind of tonal richness I call saturation, along with the tonal complexity I'd already heard -- the plumminess of a single note, and gravitas vs. vivacity. For this, I listened to J.S. Bach's Suites for Solo Cello in a new digital recording by Jean-Guihen Queyras (CD, Harmonia Mundi 901970.71), and here the contribution of the VAC Phi 200 to my system's sound made for a revelatory and pleasurable experience. In Allemande, the second movement of Suite 4, Queyras's cello sounded rich, resonant, resolute, and made for soaring melodic lines. The sound was big, sonorous, and room-filling, sometimes jumping out of the speakers in a startling way, but pleasing in all its warmth and musicality. The supreme clarity of the sound captured how precise and articulate Queyras's fingering is, how sensuously in time with his bowing. I could hear the cello's body, its depth of resonance and generous warmth, particularly when it picked up the vibrations of the lower strings to resonate in the wood, each note full of microtones and natural-sounding harmonics. Queyras's patient, even playing was never rushed, never ornate with flourishes, but lovingly pensive -- like musical thoughts, completely sensical and yet emotional as well. I could hear his short intakes of breath in rhythm with the beginnings of extended sequences of bowing. The long decay of the cello's resonance was also completely audible, even after Queyras had stopped bowing -- a precious piece of performance detail heard in live concerts but often missing from recordings. It was the best I've ever heard this recording sound. Several nights running, I listened to these two CDs many times through, deep into the early-morning hours, for the sheer enjoyment of their plush yet supremely articulate midrange capably rendered by the Phi 200. 
 
Not to ignore the VAC amp's reproduction of vinyl recordings, I listened to lots of LPs -- jazz, piano, blues, and symphonic music. These analog recordings exhibited a character in keeping with what the Phi 200 revealed of digital recordings. I played a reissue of Holst's The Planets, with Zubin Mehta conducting the Los Angeles Philharmonic (180gm LP, Decca/Speakers Corner SXL 6529). The first movement, Mars, the Bringer of War, presented a fine and articulate timbral palette. Exquisitely rendered were the tonal contrasts between the solo trumpet and horn fanfares, and between the violin section and the piccolo and flutes. Treble extension was very fine and sophisticated, but when the drumstrokes, trombones, tubas, and bass viols are all played at the climax of a crescendo, I missed some of the bottom-end slam and fullness of my reference deHavilland KE50A monoblocks. Yet with the Phi 200, each drumstroke and bass note seemed more contained in the midbass, each sound tighter, more taut and controlled, with perhaps better pitch definition, if a shade lesser in sheer impact. Again, the VAC amp had an easy time precisely distinguishing among the varied timbres of violins, horns, oboes, flutes, and piccolo. There were gorgeous contrasts of the timpani with glockenspiel, flute, harp, bassoon in Mercury, and lots of the varied tonal colors of strings, horns, and woodwinds in Jupiter. I could easily tell the trombones from the French horns. 
 
I compared the VAC Phi 200 with three different power amplifiers: my venerable VAC PA-80/80 (80Wpc; discontinued), my reference deHavilland KE50A tube monoblocks 40W;  and a pair of Herron Audio M1 solid-state monoblocks (150W, . In each case, with the same recordings, the Phi 200 proved superior in resolution, inner detail, imaging, soundstaging, speed, and pace, rhythm, and timing (PRaT). Its top-end and midrange definition, articulation, and dynamics were amazing. The VAC PA-80/80 has a much softer sound, a warmer and more prominent midrange. The deHavilland KE50As are bloomier, giving the notes more body and longer decay, and have a fuller bottom end. But the deHavillands are more Impressionist in approach, more enveloping and perhaps more dramatic; the Phi 200 was more precise. Finally, the solid-state Herron M1s somehow sounded more tube-like than the Phi 200 -- mellower, softer in attack, closer in character to the deHavillands than the Phi 200. All in all, compared to the amps in my collection, the Phi 200 seemed a new beast altogether -- unbeatable in soundstaging and inner detail, wondrous with imaging, speedy in attack, blessed with superb top-end clarity and sparkle and a gorgeous midrange, and exerting a powerful grip on the music's timing and the midbass. 
 
Conclusions 
 
Kevin Hayes has come up with something very special in the Phi 200: a tubed stereo amplifier with the speed, grip, and top-end extension of solid-state, yet with the flow, sparkle, and treble sweetness of tubes. At its listed retail price it's a serious high-end investment, but it deserves to be considered by anyone who's interested in the cutting edge of audio engineering. It's a cliché to say that the sounds of the best tubed and solid-state electronics are now closer to each other than ever before, especially if those sounds have lost something of the magic of vintage gear, but the VAC Phi 200 has a magic all its own -- there's a commanding ghost in this machine that sings clearly, cleanly, and with potent vitality. 
 
. . . Garrett Hongo
The VAC sound is audio-writ large but properly proportioned; it is elegant, opulent and ebullient.
Doug Schroder

The vastness and spatiality of the soundstage with the Phi 200 is quite surprising when heard for the first time. You may have heard many amps with differing power resources, and different levels of clarity. If you have worked primarily with solid-state amps, you likely have not heard the expansiveness a fine tube amp can bring to a system.  

The Phi 200 is a natural winner when it comes to symphonic and chamber music. The flush tonal quality of natural instruments created by the Phi 200 enlivens a score.

The Phi 200 is that good. I know any time I am not hearing sound which is up to my ever escalating standards I can put the Phi 200’s in the rig and get that which I seek. 

 When the guitar is slapped one hears what I heard in the live performance, a powerful wallop, a percussive slam from the close microphone positioning, and a highly amplified signal all reverberating off the auditorium’s wall. 

My experience with the Phi 200 is that I can be assured that no matter which loudspeaker I put into the rig I’ll get top quality sound. 

Once I have the Signature Preamplifier MkII and Phi 200 dialed-in, I do not recall any piece I have terminated due to over-aggressiveness. On the other hand, I do recall replaying favorite pieces successively in an attempt to instill more of the mood, the aura, the loveliness of it.  

As amps have come and gone, the Phi 200 has remained and if I had the means financially they would remain permanently. Their quality, reliability and unimpeachable sound earn them a resounding recommendation.

Pay Not To Play
 
I would pay good money to have Kevin Hayes, owner and designer at VAC, listen to an amplifier. If you purchase a Valve Amplification Company product you are paying Kevin to listen to your product extensively before you use it, and you should be elated. He listens to everypiece of gear which leaves VAC’s premises. Again, it is Kevin who listens, not some other worker. He is the final arbiter of sound quality on every piece of VAC gear which is sold. It is a very good thing when a knowledgeable, passionate person is at the helm of an audio company and singularly treats your component as if it is his. That kind of personal service costs more, but brings some distinct advantages to the audiophile searching for top sound.
 
Kevin is among the most well read, technically informed tube preamp and amp manufacturers in the entirety of the high-end two-channel world. When he was a teenager he pored endlessly over a tattered copy of the Radiotron Designer’s Handbook, and remarks that he has, “… collected and read thousands of pieces of literature on the creation, capture and reproduction of sound.” In describing this he states, “I don’t know why God gave me this passion for music and its reproduction, but it’s been part of the fabric of my being for as long as I can remember.” I can relate to that sense, as when I was in grade school I was already glomming onto a 1977 Lloyds all-in-one system (8 track, turntable and receiver), and shortly after assembled my first rig. I also have felt driven to assemble stereo systems in a search for “musical meaning” in sound reproduction. Consequently, this article brings together the deep desires of two men intensely searching for as close to musical perfection as can be achieved in an audio system. Kevin spends an inordinate amount of time listening to a piece of equipment until he deems the design worthy. I have listened to an inordinate amount of gear, looking for the perfect sound. That search for perfect sound has led me to VAC. 
 
Transformation of An Audiophile
 
In younger days, while Kevin was developing into a tube amp impresario, I was not so passionate about tube amps. I came of age during the ascendancy of solid-state technology and was inevitably swept up in it. When I began to assemble stereo systems I was convinced that solid-state trumped tubes on principle. I made the same assumption as thousands of music lovers; the smaller, cheaper, newer technology had to be better. How simplistic that viewpoint was!
 
Lurking in my mind was a misperception that, in some respects, still plagues the populace - that anything arising from an older technology was suspect of being inferior. Perhaps you have witnessed a person who sees a tube preamp or amp declare, “Tubes! I didn’t know they still made audio equipment with tubes.” Unless a person consumes Hi Fi periodicals, visits the right dealer or internet forum, or attends a Hi Fi show, the bias is likely to remain. Tube amps still seem on the face outdated to many and are treated as suspect devices by others. I see comments on audio sites from individuals who approach tubes as though they are inherently untrustworthy, as if they degrade sonically so quickly and have such poor distortion specs that one can’t be certain of their performance. To such individuals, solid-state is nigh unto infallible. I was like that for a long time. Part of it was that I was not into DIY, and could not afford finer tube gear; part of me wanted to believe that I sacrificed nothing sonically for sticking with solid-state because on the whole it was cheaper.
 
Over the years I have slowly been remade as an audiophile, morphing from a staunch solid-state supporter to a tube amplifier enthusiast. With growing experience hearing tube amps in quality systems, I was forced to admit that they have as much, and in some instances more efficacy than solid-state designs. I now find that I am drawn toward tube amplification like the proverbial moth to the flame. I am increasingly using tube preamps and amps in systems by preference.
 
During this process I have also revised my thinking in terms of use of tubes with less efficient speakers. Experience with the amp under review here, the Valve Amplification Company (VAC) Phi 200, has cemented my belief that solid-state is not the only game in town for electrostatic and magnetic planar speakers. In fact, paying attention more to the timbre of the music, a strong argument can be made that tube amps are the ideal for panel speakers; jacking up Watts is certainly not the only variable in attaining a pleasing result with panels.
 
Tubes and TUBES
 
There are tubes, and then there are some: not all tube amps are created equally. When approaching tube amplification one must determine early on which direction will be taken, the low-power linear circuit topology such as SET (Single-Ended Triode) amps, or larger high-output power stages with push/pull topology and a battery of output tubes. There is an alluring attribute of clarity in many of the simpler, lower power amps which is difficult to match in the higher-powered designs. With economical tube amps, one usually has to make a trade off, purity for power, or vice versa. It is rare to find both in abundance.
 
Having used both types I have at this time concluded that I prefer to trade an extremely small amount of clarity for radically increased power. Ideally, I would never have to do this, but I found myself longing for dynamic power and weight when hearing low-power amps. They simply have a tendency to sound wussy compared to higher-powered tube amps, even when paired with extremely efficient speakers. The search for ultimate-sound low-power amps radically limits the number of speakers to be practically considered, a trade off that I am not willing to make.
 
Given that a system is influenced in terms of signal purity throughout the chain, I determined that I would sacrifice marginally at the amp when it came to clarity and make up the deficiency in the other components, particularly the source. I have found the ability of an amp to create robust dynamic power an aspect too important to skimp on; but the sense of clean power can be enhanced through careful selection of attending components, especially the source and cabling used with the preamp/amp combo.
 
Let it not be misconstrued that I am advocating any intentional lowering of standards in sound quality. When confronted with real-world limitations and budgets for gear, one simply must make choices leading to the best result. In no audio system is there an absolutely perfect route to ideal sound; there are always trade-offs. I seek to trade off the potentially most damaging shortcomings for ones which are potentially least damaging. A good example is the use of power conditioning components, which invariably involve a trade-off of absolute clarity as they extend and complicate the system. One must assess whether the influence of the conditioner is overall a positive or negative.
 
At this point in time I do not typically use power conditioners in systems, as I find that every one I have used has degraded the clarity of the system in an absolute sense. I am the first house in our subdivision and the power transformer sits right outside our back door. I have clean, noise-free power lines and despite trying many power devices which utilize filtering I have always ended up returning to the good ol’ plug-in-the-wall method. This does not mean power treatment is without merit, but simply that I do not benefit greatly from it. Thus, the elimination of the power conditioner improves the overall system clarity and the amplification benefits.
 
A very practical consideration in terms of speaker selection also necessitated this decision to settle on big amps – I enjoy huge panel speakers. These are typically difficult to drive, effectively sidelining smaller tube amps. One possible panacea may be the gain feature of the Ayon Audio CD-5, an extremely fine all-in-one player/preamp, with settings of 4, 6, and 8 Volts output. With it, one has the option of matching smaller amps with less efficient speakers. Save for that indulgence, necessity exists to have ample power to drive a 2-ohm load, and sometimes much lower, typically found in larger panel speakers.
 
Love Affair with Panel Sound 
 
My first experience hearing a panel speaker was in St. Louis at a high-end shop where, shamefully, I cannot recall the name, I was overwhelmed by the majesty of the Magneplanar Tympani. I never dreamed sound could be like that! Over the years I have had the pleasure of hearing a wide variety of pleasing panels. I flipped speakers annually, if not more often, and found myself bouncing between dynamic and planar offerings. In recent years I have been migrating toward full range ESL (Electrostatic Loudspeaker) technology and have adopted the King Sound The King as my reference. Recently, I added a new version of the hybrid dynamic speaker from Legacy Audio, called the Whisper DSW. The Whisper utilizes a 4” magnetic planar midrange, so it also gravitates toward panel sound.
 
As my reference speakers have been upgraded over the past decade, so also has my amplification. In that process, I have expanded from the solid-state end of the amp spectrum to hybrids, to tube amps. This was quite unexpected for someone sold on the merits of solid-state. Once I learned that powerful enough tube amps existed to do the job, I thought that they were all priced into the stratosphere. Wrong. I ended up settling on the compromise position – tube hybrid amplification. My affordable favorite is the capable and beautiful pair of Pathos Classic One MkIII amps operating in mono mode.
 
Of late I have been on a search for a premier amplifier to drive either the DSW or the King. This is no small feat; the Whisper, though having four 15” bass drivers per channel and 95 dB sensitivity is a 4-0hm speaker and an open baffle design. Consequently, it is rated at 22 Hz – 30 kHz +/- 2 dB. It hits 20 Hz comfortably, but to extract larger subwoofer-like bass from it requires an amp with not just enough watts but also higher current. To get both of those in a tube amp usually costs much more than a solid-state amp.
 
On the other end of the speaker spectrum, the Kingsound King is a tough-to-drive electrostatic. It dips to approximately 1.8 Ohms at 20kHz, and though it has a more friendly nominal impedance of 6 Ohms, sensitivity is at 83 dB. These two speakers could hardly be more different from each other! It did not take long to learn that solid-state amps, while providing ample power, introduced problems in terms of sounding technical with one or the other speakers. The Pathi took me way down the road toward perfection with both speakers, but the ultimate answer was not to come until the VAC Phi 200’s showed up at my door.
 
Four lumps of amplification, please!
 
 There are people who take their coffee black and strong. I take my amplification big and strong. Amplification junkies break down into two types; stereo people and biamp/mono people. I’m the latter. Usually, if you give me a speaker with two sets of binding posts the following thought takes possession of my mind immediately, “Four posts… which cable will I bi-wire with and which pair of amps am I going to use?” I have done so many comparisons of amps running stereo compared to passively bi-amped and bi-wired, or actively bi-amped that I no longer wish to assemble my reference system with just one amp. (So sad. Same here.  –Ed.)
 
From the time that I first heard the King at CES 2008 and learned that Kevin used it in voicing the Phi 200, he suggested that I might use the amp with the speaker. Later, as I had taken ownership of the speaker, the possibility that I not follow up with a review of the Phi 200 was unthinkable! Seeing that only one unit was driving the speakers at the show, I assumed that one would be sufficient for the review. Kevin offered that two would be superior. But of course! Now that’s impressive; a manufacturer who offers a second amp to get the reviewing job done right! I had seldom encountered that level of commitment to me from a manufacturer in setting up a review system. It speaks volumes to me about how Kevin is only happy when the sound is correct. The suggestion revealed to me that Kevin is keen on obtaining the optimal sound, and had confidence that his amps would perform at an extremely high level in mono mode. 
 
At the first California Audio Show, the King was shown with the VAC Phi 200 to much interest and approval. There was a technical issue, as only one Phi 200 drove the pair of speakers but was using the 8-ohm posts versus the anticipated 2-ohm posts. Consequently at higher listening levels the amp was pushed to its limit and did not sound as effortless as it is capable. In my listening at home, I have tested all three settings, 1-2 Ohm, 2-4 Ohm, and 4-8 Ohm, and the King was much more controlled by the Phi 200 with the lower 1-2 Ohm terminals in use. The Phi 200 is the kind of amp that one can play a speaker like the King with confidence in stereo mode and work toward a second unit to operate them in mono mode for ultimate performance.
 
In extended use, the Phi 200 does not run terribly hot; I was surprised at how little heat they generated. The Cambridge Audio Azur 840W, a solid-state design, throws off more heat. Only if left on half a day in a smallish room would I think that they might test the limits of the listener’s temperature-comfort tolerance. 
 
Unveiling the Phi 200
 
Perhaps the term unveiling is too strong; I’m here discussing the unpacking, appearance and operation of the amp. “Dis-crating” a high-quality amp can be a bit like the dance of the seven veils, as each layer is carefully stripped away. Surprisingly, no crate was involved; custom foam pieces cradle the amp in a sturdy double box. The casing and transformer covers are nearly of military thickness, fronted by a slab-like faceplate. As a side note, custom formed foam packing pieces are quite expensive. At the time of the delivery of the Legacy Audio Whisper DSW, I was about to toss out an indistinct smaller foam piece perhaps half a meter long which was lying nearby as the transport materials were being collected. Doug Brown of Legacy Audio requested its return, “You wouldn’t believe how expensive these are!” MSRP on the piece of foam - $30. No wonder manufacturers charge hundreds of dollars for a pair of OEM boxes with foam! Take note, owner, as it can save you serious money to save the packaging. 
 
I chortled when I saw daisy chained rubber bands holding a very low tech piece of cloth draped over the thick aluminum face plate. It certainly did the job, as each amp was immaculate. Kevin will not spare a buck to attain ideal sound, but he’s sensible when arranging packaging. He’s not hung up on glam boxes as pretty velour bags inside wooden boxes don’t get the right sound out of a machine. I’ve learned to be less impressed by such things as I work with equipment. Don’t get me wrong, as a thick covering can save a component from shipping damage. I’ve seen more than one speaker’s finish impaired due to flimsy protective transport coverings. Just don’t make the mistake of thinking, “Oooh, high grade bag! This xxxxx has got to sound great!” Some components have great bags and merely acceptable sound. The Phi 200 arrives as a ruby concealed in a paper bag.
 
In terms of finish, black and silver are the two standard VAC colors, but beggars can’t be choosers, so while the Signature Preamp Mk 2 that I reviewed in March 2010 is in graphite color face, the Phi 200s features metallic silver gloss front plate. No matter, VAC gear looks rich and refined with nice, complementary hues. As the Einstein “The Light In The Dark” had a low-profile chassis, so also does the narrow chassis of the Phi 200, in a powder coat matte black finish that is uninterrupted, save for the tubes and backing wall of transformers. Sitting just behind these blocks of impedance transforming windings are the main operational switches.
 
One needs to be careful when handling tube amps as the weight is not necessarily evenly distributed across the chassis’ expanse. Wherever the transformers are, there most of the weight will likely be. In the case of the Phi 200, one must grab the amp nearly at the rear, literally picking it up at ¾ of the way to the back of the unit to prevent it from potentially slipping from one’s grip. It is a good habit to test-lift tube amplifiers to find the balance point. You do not want to be in the middle of transporting one and finding that you chose the wrong place to grab. It’s a scary feeling to have a component turning in your hand because its mass is unevenly distributed. Go about such tasks diligently and save yourself some fear or heartache.
 
Also on the top of the chassis, just in front of each pair of low-level voltage amplifier/phase splitter 6SN7 tubes, are small toggle switches allowing for selection of balanced (XLR) or single-ended (RCA) inputs. Nearby are corresponding holes for the output tubes in the chassis about the diameter of a pencil. These allow access to the bias adjustment points of the amp. A supplied small biasing tool akin to a tiny screwdriver is employed for adjustment of the bias. Behind each KT88-SC kinkless tetrode output tube is a small amber LED for assessing the biasing. This was a painless process as the controls to perform the operation are within easy reach and sight. You may have heard complaints of biasing tube amps being a PITA, but with the Phi 200 it is almost effortless. Using the tool supplied one turns the adjustment until the point at which the LED lights up. Then it is turned back until the LED just turns off. This requires slight movements; no lummoxes need apply.
 
When first installed, one has to baby sit the amp for several bias adjustment steps after the unit is first turned on respectively for 60 seconds, 90 seconds, two minutes, five minutes, and finally after 15-30 minutes. Biasing is also required whenever a tube is changed, and approximately once per month of usage. I found the amp to hold its bias extremely well. I would check often and end up not touching the settings as I could not determine that they had changed. The manual states, “Proper setting is indicated by an LED that is dark when no music is playing, but lights ‘with the beat’ as music is played.” The owner is left to determine how “heavy” the beat is to be. I put on some music with stronger bass line to adjust the bias such that the LED is never off completely but winks almost out before being illuminated by the next beat. When listening to Rapcore or Doom Metal music the light never turned off. Just kidding; I don’t listen to these genres of music.  
 
The connections behind the transformers include 15A IEC for power cord, twin sets of binding posts for left and right channels, each having a common/ground post and three posts for 1-2 Ohm, 2-4 Ohm, and 4-8 Ohm to select placement of the positive speaker lead.
 
There is an aesthetic consideration in the appearance of the Phi 200 which reveals itself when you hook it up; the inputs are behind the transformers, on the top of the chassis. My first reaction is that of appreciated sensibility; it’s far easier to see what you’re doing when setting up the amp than leaning over its side especially if the amps are in an amp stand! Officially, it was done to keep the front-to-back dimension within the space allowed by some cabinets and racks. However, it’s not so captivating to see the mongo power cord arc in the air because it’s too thick to lay flat emerging from the amp’s top mounted IEC receptacle. However, I will gladly endure this slight visual perturbation to use the Phi 200. I weep for any man who can afford this amp and whose wife kills the purchase because the power cord arises into the air. The amp is good enough that I would suggest offering new furniture as compensation. If you have stiff interconnects, they, too, will stick up in the air. If that is a problem, then consider getting longer interconnects and hiding the amps behind the speakers, a tactic which may get you noticeably improved sound.
 
The only other operational quirk I found was the fairly close spacing of 0.75-inch of the Cardas rhodium binding posts, the spacing provision of which is controlled allegedly by the insulation parts supplied by Cardas. Cables with oversized spades are placed too close to be casual about hooking them up. Though it didn’t always appear to be, there was enough room for spades of all cable types used. I made sure to use a binding post wrench, available from Audioquest and Cardas, to prevent possible slippage of the spades. 
 
Reading required
 
Even an Owner’s Manual can reflect on the nature of the designer. The Phi 200’s manual describes features and has no diagrams. It is anticipated that someone who lays out long green for a premium instrument will care enough to read what and what not to do with the amp. Hence, a thorough discussion of the operations in the manual, a walkthrough if you will, describes the experience of using the Phi 200. Starting with the safety notices on the first page, tidbits of advice assist the new owner, among them:
 
Avoid power conditioners that float the ground pin. 
A 12V trigger cable can be used to turn the amp on and off via external device. 
“Pay close attention to power quality, and be aware that different power cords can alter the sound.” (Bravo! An amp manufacturer who acknowledges the critical nature of power cords!) 
Discussion of break in period -  approximately 200 hours. 
Description of the appearance of tubes operating normally, as well as ones which are “running away”, being destroyed due to excessive current when seated improperly or defective. 
Expectations regarding tube life and quality, and VAC selection of its tubes for use with the Phi 200, as well as a list of equivalent tube numbers for tube rolling. 
Explanation of Impedance Matching, including the option of using two different impedance output posts for bi-wiring speakers (However, use of 4-8 Ohm posts are required for Mono amp mode with low efficiency speakers like ESLs). 
 
As one reads, it becomes clear that Kevin anticipates the new owner to consider his amp an instrument for fine music reproduction. Years of experience as a designer and music enthusiast are coalesced into the Manual, and I recommend careful reference to it.
 
“VAC Facts”
 
Before delving into discussion of the sound of the Phi 200, I would first like to stimulate your intellect as to the quality of the Phi 200 and VAC gear in general by alluding to what I call “VAC Facts”. These are lesser known packets of knowledge regarding development of the VAC Phi 200 amplifier. These VAC Facts are not merely for entertainment; they are stepping stones to understanding the radical commitment of Kevin Hayes and VAC to bring you the ultimate in audio componentry. Good sound needs to rest on good design principles and good execution. The VAC Facts speak to these and beckon rationally to those who are seeking ultra high-end electronics. As you read them, these testaments to quality will lead you to conclude that VAC authentically cares deeply about product integrity and sound quality.
 
VAC Fact: The Phi 200’s name is not mysterious, as Kevin merely followed convention in audio circles by using a letter of the Greek Alphabet. It may not be an exaggeration to say that half the Greek alphabet has been sourced to name audio components and technologies.
 
VAC Fact: The company builds “Stereo Beam Power” amplifiers. This is a reference to avoidance of standard Tetrode tube designs. According to Kevin, a “beam tetrode” or “kinkless tetrode” causes the electrons to flow in sheets or vertical beams, while repulsing secondary electrons. The design allows for removal of the third grid inside the tube, leaving the anode and cathode. The design is more efficient and yields greater power output than a pentode tube. The KT66 and KT88 are the most successful implementations of this technology in terms of audio quality.
 
VAC Fact: The Phi 200 is a proudly hand built American product. However, it uses a new twist on the power tube, the KT88-SC. Chinese tube maker Shuguang makes it and the 6SN7, both of which are deemed better than NOS tubes! Kevin states that they are notable not only for superb sound, but superior longevity as well.
 
VAC Fact: The Phi 200 was introduced at the 2008 Rocky Mountain Audio Fest (RMAF). Two revisions have been introduced, namely the addition of the MONO switch, and a LOGO ON/OFF switch.
 
VAC Fact: The KT88-SC power tubes operate in ultra-linear mode and feed two 15-pound VAC output transformers based on classic transformer design.
 
VAC Fact: Kevin adheres to a “divide and conquer” philosophy when designing higher-power amps. Per Kevin, “Most designers go for larger parts; I think more along the lines of parallel processing (which, of course, is now all the rage in DACs and computing).” The Phi 200 in Mono mode is very much like his design for a stand-alone mono amp, and benefits from the design of the Phi 300 which was a Stereo/Mono design.
 
VAC Fact: Kevin shares, “If there is one thing I have learned in twenty-plus years in audio design, it is not to prejudge things..... I never assume that a particular tube type, capacitor, circuit topology, etc. must be the best. I do not let my theories tell me about the real world; I try to let the real world correct and refine my theories. To that end, we conduct frequent R&D projects that run contrary to our assumptions. In this way, we learn, grow and produce much better instruments than we could have imagined.” A sign in VAC’s listening room reads: In theory, there is no difference between theory and practice. But, in practice, there is.
 
VAC Fact: The cost is similar to acquire one Phi 300.1a or two Phi 200. Which would yield superior results? According to the designer, “I think the pair of Phi 200 would have a slight edge with regard to detail, extension and dynamics. Ah, but then there are the Mono 300’s…”
 
VAC Fact: The three transformers of the Phi 200 weigh more than half of the amp’s total weight.
 
VAC Fact: The Phi 200, like all VAC products, is designed such that you can leave it to your grandchildren in your will. It is crafted to last. The anticipated first major service is the refreshment of the power supply capacitors – after approximately 40-50 years!
 
VAC Fact: There are eleven sets of speakers currently being used at VAC for the voicing process: five sets of dynamic, three sets of full-range electrostatic, one set of hybrid electrostatic, and two sets of horn speakers! The amp was not designed solely to drive the King ESL, but the King was used in the voicing of the Phi 200. Improvements to a VAC design are only accepted if it sounds better with some or all speakers tested and worse with none.
 
VAC Fact: The voicing process may take Kevin and VAC engineers up to 1,000 person-hours in some cases; that’s beyond the time taken to get the amps to measure well on the bench! If Kevin does not approve the sound of an individual component (he listens to each one), it does not ship. Production of certain models has ceased at times for up to two months while tracking down a variance in vendor’s products, such as wires or capacitors.
 
VAC Fact: The voicing process of the Phi 200 was thought to be done until a pair of Zingali horn speakers were hooked up. Through the Zingali, the circuit sounded bright, yet soft, which called for an adjustment to increase the control and precision of the top octave. The cure was affected, but the change was completely inaudible on a pair of Thiel speakers.
 
VAC Fact: Kevin’s opinion of Class D amplification, “… we have neither seen nor heard anything in theory or in practice to suggest that Class D would be a good idea with regard to sound quality.”
 
VAC Fact: At the upcoming 2011 Consumer Electronics Show (CES) in Las Vegas, VAC will introduce the Phi 200i, an integrated amplifier mechanically like the Phi 300.1a, but with 110 wpc. It is designed to overcome many of the shortcomings of integrated amps. It uses two separate power transformers, one for the pre and the other for the power amplifier. It will include a genuine line stage as opposed to being an amp with a volume control, and phono stage. Kevin says, “It should be roughly equivalent to the combination of Renaissance MkIII Preamplifier and Phi 200 Amplifier.”  Also on the horizon is the Sigma 160i integrated amplifier (see, another Greek letter name) which will look similar to the Phi 200 a
 
Get a listening VACcination
 
Got the jitters, a bad case of Audiophilia Nervosa? Can’t seem to find that perfect sound? Nothing seems real enough sounding to you? Doctor Doug says get a shot of VAC equipment and you’ll start feeling better. I certainly feel better every time I use VAC gear in the systems I build. I do mean every time. If there has been one amplifier which has never failed me when reaching for top shelf sound, it is the Phi 200.
 
I already stated in the Signature Preamplifier MkII review that the preamp saves other brands of amps from poor performance; it literally preserves them from ignominy. I can say the same of the Phi 200. Of all the amplifiers my hands have touched thus far reviewing – you can check the list of my reviews – the Phi 200 is the amplifier I would keep. Following are the reasons, based on my listening impressions.
 
VAC equipment has an uncharacteristically big, beautiful sound. I first heard the Phi 200 with the King ESL. Am I glad I did, because there is a possibility that under show conditions hearing it with a different amp I may have dismissed it - a huge mistake. The King is extraordinarily good, and has sounded better with the Phi 200 than with any other amps I have used. I have used some good solid-state and hybrid amps with the king – Cambridge Audio Azur 840W amps in Bi-amp configuration, Pathos Classic One MkIII hybrids in Mono mode at 270wpc into 4 Ohms, a pair of Moscode 402Au, and the Einstein “The Light In The Dark”, as well as some others currently under review. I have had the Phi 200 on loan long enough to have compared it in more head-to-head listening tests with other amps than any other amp I have reviewed. I have heard the Phi 200 on about as many speaker systems as Kevin has for voicing. The conclusion is clear: the balance of power, fullness, and correctness is unparalleled. The King sounds good with one Phi 200, but is inspirational with two of them in Mono mode.
 
Recently a local dealer for VAC instruments came to my home twice to hear the King. The first time he heard it with solid-state amplification and thought it was nice. Prior to his return I told him, “Just wait until you hear the King with two Phi 200’s!” This time he brought his own discs, and this time he left with the phone number of Roger DuNaier at Performance Devices, because he had made up his mind he needed to carry the King as his ESL. It speaks well of an amp when a dealer is swayed to carry a line of speakers from hearing a system which has only had it inserted! The Phi 200 is that good. I know any time I am not hearing sound which is up to my ever escalating standards I can put the Phi 200’s in the rig and get that which I seek.

Rodrigo Y Gabriela
 
If you haven’t had opportunity to look up an incendiary guitar duo named Rodrigo Y Gabriela, I encourage you to do so. This fast paced, punch-packing acoustic guitar pairing has become a favorite for listening as well as conducting demos of equipment. I highly recommend their Live in Japan disc.
 
One track, named “FOC” – I’m almost afraid to know the meaning – has an extended percussion segment with the bodies of the guitars used to thump and pound out the driving rhythm. The clarity and depth of the Phi 200 is exemplary, allowing one to hear much further into the acoustic space of the venue than with the aforementioned amps. The Phi 200 seems to harbor more power than its specified rating. When the guitar is slapped one hears what I heard in the live performance, a powerful wallop, a percussive slam from the close microphone positioning, and a highly amplified signal all reverberating off the auditorium’s wall.
 
One does not hear from the VAC what most amps do to Rodrigo’s picking and plucking, a thinning out of the wiry notes. While initially such thinness is quite noticeable and seems captivating as “detail”, after a short while it becomes irritatingly brittle sounding. At first blush the VAC components may seem laid back, too reticent. But when listening to such intense playing  and at higher levels for several minutes, much less a half hour, that more controlled expression of the string’s snap is very welcome as fatigue does not set in. In fact, fatigue never set in with these amps.
 
It reminds me of the lack of strain on the eye looking at a sunset versus summer midday sunlight. The sheer brightness of the sun causes one to squint, to filter out some photons crashing into the iris, but the late afternoon sky is much more forgiving. In the same way, some amps hand the music to your ear “bright and white”, strong and clear but in such a churlish manner that the ear wants to “squint”. Not so with the VAC, as you can put on truly harsh tunes and have the ear wrenching audacity of it ameliorated.
 
I have a couple of nastier test pieces for systems, ones which most systems even at shows fail miserably. One is Lenny Kravitz’s “American Woman”, and another is Apocalyptica’s “Enter the Sandman”. Kravitz plays with the vocals toward the end of the song, distorting his voice out of all proportion to decency. Even on good rigs he sounds so awful that I can usually not listen to the end; he comes across as a robot with a bullhorn singing. As for Apocalyptica, a truly hard driving band with three classically trained cellists and a drummer, I have not much good to say for the music; I just like getting a kick out of seeing if a system can handle it. The strings screech wretchedly, just the kind of effect needed to test the limits of a stereo’s top-end performance!
 
Watch out if you tee up either one of these to hit, because your system is likely to slice and send them sailing “out of bounds”. Only a handful of times have I avoided the cringe-factor when hearing these pieces and one of the only systems to handle them with any kind of aplomb was in my room with the Phi 200. The mollifying effect of the Phi 200 is to make these abominations sound like music. I can actually listen through to the end and pretend like I appreciate it. Anything less than fantastic amplification and these pieces get an automatic penalty; stop the music and move to the next artist.
 
Once I have the Signature Preamplifier MkII and Phi 200 dialed-in, I do not recall any piece I have terminated due to over-aggressiveness. On the other hand, I do recall replaying favorite pieces successively in an attempt to instill more of the mood, the aura, the loveliness of it. I usually want to move ahead, go on to the next experience, but I may repeat a performance when the Phi 200 is in the rig and feel it’s no waste of time. 
 
More Stringent Criteria
 
Increasingly, as I age I am not interested in brightness, or “definition at all costs”. When I was younger I was willing to put up with such antics, but no longer. I have not capitulated on the demand for detail and definition. On the contrary, I demand them more than ever, but with the condition that they must be musically appropriate to the genre and recording. There are only two situations in use of power amps where I can say that both of these demands have been met to my satisfaction. One is with a trio of Coda CS amplifiers (under review) operating the Legacy Audio Whisper DSW in fully active crossover mode, a setup which gives a very unfair advantage to a solid-state amp.
 
The other is the more traditional loudspeaker of either the King Sound King or the Whisper DSW operating in passive crossover mode, powered by the pair of Phi 200 amps. That this setup can compete with a six-channel fully active crossover system is a testament to the authority and quality of the Phi 200. The best part is that the authority and quality is transferrable to any dynamic, full-range ESL or horn speaker system. 
 
No kidding around
 
If you like upbeat vocals, you might want to check out Bobby McFerrin’s VOCAbuLarieS, in which he employs more than fifty singers weaving them into his energized African-inspired choral and solo works. The first track, “Baby”, is infectiously repetitive and upbeat as it brings to mind the runabout antics of a small child.
 
In comparison with the Einstein “The Light In The Dark”, the closest amp in quality to the VAC of those I have used, I found the Phi 200 to offer more heft in the bass singers’ voices, a touch more smoothness in blending all the singers and comparable clarity. When using the Ayon CD-5 as source with its internal preamplifier’s selectable gain setting at MID (6V), vocals sounded as if emanating from oversized heads. This effect was compounded when hearing it through the King, as ESLs tend to expand the center image anyway. With use of the 1-2 Ohm posts on the King and the GAIN of the CD-5 set to LOW (4V), the singers became more life sized and properly weighted. There is a terrific amount of flexibility offered by pairing higher-output sources like the CD-5 with the Phi 200, but you will want to watch out using output over 4V as it will likely begin to “inflate” the amp’s performance. Some people may adore that big-as-the-room sound, but others will want to rein it in.
 
The VAC sound is audio-writ large but properly proportioned; it is elegant, opulent and ebullient. The vastness and spatiality of the soundstage with the Phi 200 is quite surprising when heard for the first time. You may have heard many amps with differing power resources, and different levels of clarity. If you have worked primarily with solid-state amps, you likely have not heard the expansiveness a fine tube amp can bring to a system. 
 
Perfect Storm System
 
The Phi 200 is a natural winner when it comes to symphonic and chamber music. The flush tonal quality of natural instruments created by the Phi 200 enlivens a score. I recently picked up James Horner’s soundtrack for The Perfect Storm, a Deadliest Catch-like account of the Andrea Gail, a long line fishing vessel doomed at sea in one of the worst meteorological disasters to hit the eastern seaboard in a century. As an aside I recommend not only the movie but also the book; so much more of the human element comes through in the painstaking recounting, including a morbid description of what likely the men onboard were undergoing as their ship foundered, sank, and they drowned. The grandeur and gruesomeness of commercial fishing off the Grand Banks is compelling to the spirit of those who labor with their hands as well as those who cheer people finding themselves on the short side of the odds.
 
I like to see what an amp can do with powerfully orchestrated pieces. In The Perfect Storm soundtrack, the periodic wave action flow to the music captures the vicissitudes of the sea. The Phi 200 does not drain the life from the piece, as some amps do. It is easy to be at sea, visualizing the images from the movie; with the VAC I’m not distracted by a question of how that particular horn sounds or why a drum does not seem deep enough. All is rendered with tonal correctness and proper weighting, so I can relax and immerse myself in the moment.
 
Especially rewarding are the tracks “The Decision To Turn Around” and “Rogue Wave”, both of which have attacks of low register horns and tympani. The Phi 200 is exemplary in capturing the surge of the symphony as it crashes in crescendo, emulating the killer waves of the ferocious hurricane. In “Rogue Wave” the last, sustained trumpet blasts speak of panic, heroism – anything that grasps at another moment of hope. The swirling strings and building wall of drums tear at the heart as one conceives the wall of watery grave about to engulf the hapless crew. Following the pounding of the vessel and its sinking an eerie silence ensues, and inevitably the ebb and flow of the ocean’s sub-surface melody is enjoined once again. The humans were no match and will not be remembered by the sea, but washed from memory. The Phi 200 captures the terrific undertow of the score, pulling the ear downward toward the depths in an overwhelmingly compelling fashion. 
 
Ideal for any speaker
 
My experience with the Phi 200 is that I can be assured that no matter which loudspeaker I put into the rig I’ll get top quality sound. About two months ago another manufacturer was visiting for a couple days in order to establish a speaker for review. The VAC components were in use, so it was not surprising to me that I found out later he had enthused to a cable manufacturer that my rig was special. I hadn’t even gotten a chance to work with the speaker for weeks to dial it in. Already with the “first run” the system was charming; the VAC gear was working its magic.
 
I find it difficult to determine which system I prefer, the big panels or the big dynamic hybrids. The Phi 200 in mono drives them both with authority and acuity. With most amps I have to work hard to get a sustainable level of palpability, of convincingly true-to-life sound. Not with the Phi 200. In a matter of one evening I can dial it in to find a viscerally moving experience.
 
Here is a secret about how I build high-end systems. I do not spend weeks or months sitting around pondering their sound. If something does not sound right I act directly and immediately to make the effected repair. Consider that industry leaders head to a show and set up in a room from scratch. They do not have weeks or months to futz with sound. They must get it right as best they can, many times literally overnight. Some are definitely better than others, but most do a commendable job given the schedule and circumstances.
 
I have found that it’s counter-productive to waste weeks and months seeking an optimum sound when the ear senses an obvious defect. If a system doesn’t sound good to me I do not wait on it, I change something! For this reason I keep two or three types of cables on hand in order to tune rigs. There are tens of thousands of permutations available for systems. Why should I waste weeks or months of my life with a so-so sound when I can potentially improve it immediately? The longer I have been in the game the less patience I have to adopt a “wait-and-see” attitude. I have a firm grasp of my electronics collection and media collection, as well as how I demand it to sound. If it’s not where I want it to be, I’m not about to spend weeks suffering its insufficiency. Something’s getting reworked! Of course, finances can slow down the process, but if finances are not hindering and the rig doesn’t sound right, it’s not going to stay that way for long.
 
Imagine the number of audiophiles who sit in discontent at their rig’s sound, pining for improvement! How many hope that it will improve on its own with weeks or even months? If you don’t want to spend the majority of your time as a discontented audiophile, get to work! I spent far too many years hoping for incremental improvements, so I want to encourage those who are frustrated not to accept waiting and doing nothing. If there is an annoying aspect to the system, change a power cord or two, or try a different speaker placement, or put a pillow behind the speaker to test if room treatments might help. Your ears will tell you if you are going in the right direction, just as your eyes tell you when you see a beautiful person. Influence change for improvement rather than be a victim of inaction.
 
However, once a very pleasing sound has been found I slow the process down every bit as dramatically. The ear will tell you when it hears something good. When my ear sends the signal, “Ah! I really like this sound,” I halt the system reconfigurations and spend time enjoying. More often than not the system will remain fixed for some time and I will authentically thrill to the sound of it for weeks. It’s so much better than leaving niggling concerns about the sound unaddressed. If I get my concerns about the sound dealt with up front, I find myself much more content with the system for longer periods of time such that I become reluctant to disassemble the rig!
 
When I’m in “Reconfiguration Mode”, usually cables are the first to be reworked, partly because they can be incrementally changed, and partly because they are easiest to work with physically. If I’m confident of the source’s quality then the next thing to be considered for change is the amp. But never the VAC Phi 200. I have moved it in and out of the rigs I have built enough times that I have heard the devastation resulting from its removal. It has become an “anchor component” which has proven itself the best option no matter which team of components I assemble. Inevitably, it is re-inserted into the system to restore much needed vitality. When another amp’s review work has been concluded, out it goes and in goes the Phi 200. I have preferred over the months to build rigs around it rather than work without it. This confirms Kevin’s voicing process, whereby the amp is conditioned to be compatible with a wide range of speakers.
 
Thus it was that recently when I put the Whisper DSW back into the rig I instinctively reached for the Phi 200’s, no matter the other components and cables. I keep an updated exact system list from power cord for the source to speakers for the “Best Rig” with every speaker system. I could have simply recreated my previous best rig. However, I decided to fly solo and rework the cabling again. In the span of two hours and four partial cable changes, I was content. The results obtained are often so right, so spot-on that I leave it that way for weeks until another review priority forces change. As amps have come and gone, the Phi 200 has remained and if I had the means financially they would remain permanently. Their quality, reliability and unimpeachable sound earn them a resounding recommendation. 
 
In conclusion I leave you with two more VAC Facts.
 
Firstly, Kevin is also interested in the quality of the discovery and reporting in regards to his products as they are used in real-life systems. He is not so concerned with analyzing specifications to death, but rather what works in terms of obtaining the best sound. This review is my most comprehensive to date in terms of an amplifier’s use with other components. I subjected the Phi 200 to more sources, preamps, cables and speakers – systems - than any previously reviewed piece. It yielded top-quality sound with a large body of available components.
 
Secondly, with CES around the corner and enthusiasts hearing his components, I suspect Kevin is about to get a lot busier. If you like what you hear and seek a VAC instrument, be patient. Your patience will be well rewarded. Kevin’s concern is producing a quality instrument above all. You are paying him for the best amp he can build, and he’s going to make sure you get it. That is why he’s going to listen to it before it ships. 
 
Manufacturer’s comment:
"Thank you for the thorough and thoughtful review of the VAC Phi 200, as well as for the courtesy and professionalism always shown us by everyone at Dagogo.
 
A quick note about the VAC / KingSound demonstration at the inaugural 2010 California Audio Show. After discussions with the dealer, Bob Kehn of Audio Image, who presented the room, it was determined that the King’s panels likely were not fully charged most or all of the time, which results in reduced sensitivity and premature clipping of the panels themselves. The problem was that the speakers were left unplugged when the alternate Magico speakers were being demonstrated. Normally I would not have thought of this, but we experienced a similar issue during setup at Axpona; the speakers had to be plugged in (and unplayed) for several hours before they would play normally. Clarity about this is important, as we would not want the King’s to get a reputation for being difficult to drive, nor would we want the stereo Phi 200 to be viewed as marginal for the task!
 
To clarify the bias setting of the output tubes, the proper procedure is performed without music playing, as initially stated in the review. Once the proper settings have been achieved, in normal operation one will notice that the LEDs will be dark when no music is playing, and will light ‘with the beat’ as music is played. However, this is not part of the adjustment procedure, and there is no need to select a particular kind of music, etc.
 
Thank you again for taking the time to review the VAC Phi 200. We count it a privilege".
 
Kind regards,
..........Kevin Hayes / VAC
the VAC’s sonic disposition, which I consider to be among the very few designs with that organic, natural touch. The music was, in fact, better and more melodious than I expected...nothing has been as impressive as the two-piece Renaissance Signature Mk .
INNER EAR

The VAC faithfully reproduced the instruments performing in the high frequency domain. Trumpets had the distinctive bite of horns and it was quite easy to distinguish cornets from other horn instruments. I couldn’t help but be impressed with the VAC’s knack to reproduce saxophone, revealing the swishing, smooth sound of the instrument as it moved air swiftly through its reeds. This, along with the preamp’s ability to extract subtle detail was, again, like a live performance in my listening room.

The system’s ability to handle and control the softest as well as the loudest musical passages — its dynamic range — was beyond compare and it was quite evident that the VAC’s presence heightened the system’s musical caliber.

A Music-Lover’s delight - Aesthetics And Technology Merged
 
My recent audition of the Focal Scala loudspeakers (on this website) was my introduction to this preamplifier. It was used to drive the 300 watt/ch Boulder 1060 power amplifier and accommodate the Teac Esoteric CD playback system — all scheduled for review. This is VAC’s top-of-the-line preamplifier and the most recent component of the Signature series, which, I understand has been around for over eight years. I haven’t paid much attention to VAC, but am familiar with some of the products I have auditioned at trade show and at dealers — and while they all sounded good to me, nothing has been as impressive as the two-piece Renaissance Signature Mk II.
 
As I am of the opinion that the most important component in a system is the preamplifier, I was immediately impressed with the sonic purity and musical authenticity the above-mentioned system communicated. This prompted me to examine and research the VAC’s function as a line-stage component and, of course, a switching device.
 
Appearance
 
Well, if looks alone could communicate sound, you would be impressed. The two components exude elegance and refinement. They offer a touch of class rarely seen in the audio business where utilitarian designs dominate. The VAC components aren’t small and cute, like some expensive electronics I am familiar with, but then again they do not appear ostentatious. Their dimensions hint at their importance, their weight suggest solidity — and the separate power supply demonstrates audio technology done right.
 
The sculptured faceplates must have been made from a solid block of aluminum — they are 3/8 inch thick with the edges chamfered to about 1/4 inch. Finished in silky gold-speckled black, the faceplates are an almost artistic likeness of the VAC’s sound quality. To guarantee quality, all chassis parts and lacquering are done in-house.
 
The main unit features two large gold-plated knobs for gain and input selection and two smaller ones on the left and right of the faceplate function as tape monitor and cinema direct, and mute on/off. Nice, logical layout and highly appreciated by this reviewer who, like many consumers of high-end wears bi-focals and hates to fumble.
 
The rear panel is logically arranged and provides two sets of balanced inputs (earlier versions had one) and they can be set for RCA or XLR connectors. The line-stage version is available with up to six single-ended inputs, or up to two balanced with four single-ended inputs in addition to the tape loop. The units equipped with the phono stage offer a load control.
 
The power supply chassis for the line stage (the phono stage is optional and adds another component) is a visual match with the same size and appearance. On its front are two big meters surrounded by gold-plated frames. These meters monitor heater and main voltages and indicate when the operating voltages are perfect. The finishing touch on both units is VAC’s backlit logos, which glow red when muted and blue when in operation. The main unit measures 18" wide, x 5.5" high x 14.5 deep (plus knobs & connectors); power supply 18" x 3.9" x 14.5" plus connectors
Shipping weight: 80 pounds total (with phono) or 65 pounds (without phono)
 
A snazzy remote control comes with the unit.
 
The Sound
 
Ideally, a really great preamplifier should have little or no sonic signature which to add to a sound system. That however, is not reality, as all components in a system will add (or subtract) sonic peculiarities. A system’s final sound is influenced by all components, beginning with the AC power cord and ending with positioning them in the listening room. When we consider all contributory components of a system, it stands to reason that, ultimately, we hear the result of either a synergistic arrangement, or one that diminishes a musical performance.
 
The trick is to be familiar with enough components to achieve synergy and, most importantly, have at least some knowledge of live music — the only legitimate reference. This said, here is how I find a component’s sonic temperament and get a pretty good idea of its compatibility with other components in a system:
I always use piano recordings that are well known to me; they include Yamaha, Steinway, Baldwin and Boesendorfer pianos — all with their particular personalities. When I can recognize the sonic character of these different pianos, I know that I’m onto something special. I then assess the component’s additional capabilities. I look for its ability to recreate a soundstage, its capability to capture and reproduce harmonics, space, timbre, resolution, and, of course, its musicality. The music I used for this evaluation is part of a collection of well-produced jazz, blues and classical CDs. Rather than talk about my choice of music or one or the other track, I would like to point out that the genre isn’t or should not be as important an issue as that of concluding the musical material in its entirety.
 
I brought my own Wyetech Labs Ruby mono-block power amplifiers to establish a reference with which I am familiar, and evaluated The VAC’s performance based on this and the Boulder system combination. I should state here that in my own systems, I use the Wyetech Labs Ruby preamplifier, which I regard as a credible, indeed a reference component that keeps outperforming most preamps I have run across. On rare occasions, I have found that it was not compatible; although relatively neutral-sounding, it has the propensity to be heartlessly revealing. Simply put, it can sound rather clinical when married with the wrong power amplifier and source components. Nevertheless, my first auditions were with the VAC connected to the Boulder amp with the Esoteric separates as source components. This system arrangement achieved such a high degree of realism that it left me with the impression that I was listening to a piano in the room with me. When I switched to the Wyetech Labs amps, two elements became known.
 
Firstly, it was a good match and allowed the amplifiers to perform at their best. This is a tip-off regarding the VAC’s sonic disposition, which I consider to be among the very few designs with that organic, natural touch. The music was, in fact, better and more melodious than I expected, yet, I recognized the amps’ speed, clarity and articulation (a good thing, for it allows users to choose amplification that suits their taste).
 
Secondly, though I recognized the Wyetech Labs’ sound, I also noticed a slight overall tinge, the sort that actually enhances the musical properties of pitch, rhythm and tonal colour. While this is an entirely personal opinion, I believe that the VAC introduced a stage of musicality, more closely resembling an unamplified performance where there isn’t pro-sound equipment with its colouration and potentially inflated dynamics to deceive the listener. Nevertheless, The Wyetech Lab amps sounded a bit colder than I anticipated.
 
With the VAC connected to the Wytech Labs and Boulder amps, I began to listen and compare the sound of the two system configurations. However, after I had listened to half a dozen tracks on both systems, I decided to continued and play back all of my piano CDs on the Boulder system, which I thought was a better musical arrangement. On it, my piano recordings were more revealing, thus better approximating the various instruments’ signature. This plainly showed that the VAC/Bolder combination presented the synergy needed to elicit the necessary harmonics — the stuff that reveals an instruments personality.
 
The VAC faithfully reproduced the instruments performing in the high frequency domain. Trumpets had the distinctive bite of horns and it was quite easy to distinguish cornets from other horn instruments. I couldn’t help but be impressed with the VAC’s knack to reproduce saxophone, revealing the swishing, smooth sound of the instrument as it moved air swiftly through its reeds. This, along with the preamp’s ability to extract subtle detail was, again, like a live performance in my listening room. 
 
Highs, produced from violins, pianos or triangles, all sounded crystal clear and without even a hint of stridency or glare; yet, the instruments sounded authentic and the system’s resolution was accomplished right up to the dog-whistle range. However, the highs never dominated the midrange frequency segment — the most important part where most of the musical material and voices are. 
 
Voices, whether they were tenors, sopranos, Luis Armstrong or Kathleen Battle, were as natural as I remember them from live performances. The VAC certainly has the ability to “extract” timbre and hue and clearly shows the personality of the singers. I
 
t is interesting to see/hear that complex music written for large orchestras seems to come together harmoniously, but simultaneously allows singling out any one instrument of the orchestra. Inner detail is simply superb and marries effortlessly with dynamics. Forte and fortissimo passages are within a comfortable scale and come across very organic. Nothing seems out of balance and that at very high and very low volumes (If you have neighbors that complain about the volume, turn your system down — you’ll not loose any detail).
 
Bass is made up of frequencies ranging from about 80Hz to 160Hz (upper bass) and from 160Hz downwards. The VAC handles all of it with the proper authority (resolution) and substance. There are loads of harmonics above fundamental notes and I found it pleasing when listening to contrabass, electric or synthetically produced music. It doesn’t dominate, but it is resolute with appropriately reproduced tonal distinction. Bass drums and, my favourite, Hammond B3s literally got me off my seat as I could picture Jimmy Smith and company (on an old CD titled Some Serious Blues) playing for me.
 
The only thing left to say is that imaging isn’t good or even very good, it is out of this world; and it’s out of the speakers. I wouldn’t call it three-dimensional, I’d call multi-dimensional with instruments on the (invisible) soundstage in revealing focus. The soundstage has sensible boundaries and there is a realism relating to the size and location of the instruments. When the setup is right (and mine was) it is difficult to locate the loudspeakers with the eyes closed.
 
Synopsis
 
At the end of the auditioning session, I wound up listening to some CDs just for the pure enjoyment of music. In fact, a couple of weeks later, I returned with contributing Editor David McCallum for one more listening session; and we both simply sat, listened and appreciated the result of this very carefully assembled system. We didn’t really “audition”, we listened to a variety of music — some parts with very complex arrangements — and talked about the system’s knack of not getting in the way by emphasizing one or the other component. Later, when we discussed the sound, we agreed that the entire system was special; not because of any one element being better than we have heard before, but because of its all-round ability to deliver a live-like performance. The system’s ability to handle and control the softest as well as the loudest musical passages — its dynamic range — was beyond compare and it was quite evident that the VAC’s presence heightened the system’s musical caliber.
Simply put, the VAC Phi 300.1 is the best sounding tube power amplifiers made under US$25,000.
Sound by Singer
It’s hard to get your head around the idea that an amplifier which sells for more than US$23,800 is a bargain; but, in fact, when you consider what the VAC Phi 300.1 sounds like and that it is able to translate that sound to just about any speaker out there, regardless of efficiency or load, IT IS. Simply put, the VAC Phi 300.1 is the best sounding tube power amplifiers made under $25,000. Select two of them bridged into mono and you are hard pressed to find anything other than VTL and Zanden which will even give them a run for their money!
 
The VAC Phi™ 300.1 is an extremely potent amplifier with power, superb definition, and great control. Its eight beam power output tubes yield 300 watts in bridged mono mode or 150 watts/channel in stereo mode at the choice of the user. Front panel level controls may be engaged to aid in balancing bi-amplified systems. Both balanced XLR and single-ended RCA inputs are provided. Triode operation may be selected at the flick of a switch. The chassis is machined aluminum, with the tubes beautifully showcased behind 0.75" acrylic glass. Also included are standard 12 volt triggers.
 
The Phi 300.1 is VAC's finest stereo amplifier. It is based on their direct coupled input & driver circuit that results in the fastest, fullest, most detailed sound that they have ever achieved. You will be surprised by details in your recordings that you had never heard before. The ambience and retrieval of reverb and decay information is particularly surprising.
Using eight beam power output tubes and a low-mu octal driver, this amplifier possesses an uncanny ability to reveal every nuance in a recording, while preserve the emotion and feel necessary for a truly musical performance. In addition to finesse, it has great power, impact, control, and a low electrical noise floor. This remarkable overall character makes it suitable for use with speakers ranging from high efficiency to the most difficult and demanding.
 
Both single-ended and balanced (fully balanced amplifier mode) inputs are provided. The chassis is custom machined 0.25" aluminum welded into a solid unitary structure, finished in metallic black paint. The 1" thick aluminum front panel is finished in hand rubbed silver metallic lacquer, with bias meter and tube adjustors that make it easy to maintain and optimize. Output matching taps are provided for 2, 4, and 8 ohm speakers.
 
We thought it would be impossible for any one including VAC to build a better amp than the PHI300.1 so of course they went ahead and did enterTHE VAC Statement 450 monobloc.
The sound of the Statement 450 literally caused our jaws to drop.
Sound by Singer
The sound of the Statement 450 literally caused our jaws to drop. If the Phi 300 is one of the world's best amplifiers, then the Statement 450 is no less than the redefinition of the term "World Class". It is not a subtle improvement. It is a whole new world. 
 
VAC President Kevin Hayes describes its sound as follows: "This is an absolutely startling jump in sound quality. The voices, images, and dynamics are as solid as a concrete wall, and there is an order of magnitude more detail being presented, which manifests not only in hi-fi terms, but in emotion and, for example, being able to picture the expressions that play across a singer's face. It's not a subtle difference, or even a moderate difference; it is a quantum jump." 
 
VAC's "first principles" design approach led us to four critical factors in the design and voicing of the Statement 450: increased precision of control over the drive/output circuit; control over stray interactions within the amplifier; 
   architectural control of mechanical resonances; and avoidance of electrically large, slow components. The result is, predictably, a design completely unique to VAC. 
 
The sound of the Statement 450 literally caused our jaws to drop. If the Phi 300 is one of the world's best amplifiers, then the Statement 450 is no less than the redefinition of the term "World Class". It is not a subtle improvement. It is a whole new world. 
 
VAC President Kevin Hayes describes its sound as follows: "This is an absolutely startling jump in sound quality. The voices, images, and dynamics are as solid as a concrete wall, and there is an order of magnitude more detail being presented, which manifests not only in hi-fi terms, but in emotion and, for example, being able to picture the expressions that play across a singer's face. It's not a subtle difference, or even a moderate difference; it is a quantum jump." 
 
VAC's "first principles" design approach led us to four critical factors in the design and voicing of the Statement 450: increased precision of control over the drive/output circuit; control over stray interactions within the amplifier; architectural control of mechanical resonances; and avoidance of electrically large, slow components. The result is, predictably, a design completely unique to VAC
VAC: Thoughts on Amplifier Design
VAC website

                           - Including why VAC does not make single-ended power amplifiers -

Some audiophiles, drawing on single-ended experience, will assume that a triode amplifier produces vast amounts of second harmonic distortion.  Interestingly, the triode vacuum tube in and of itself is the most linear amplifying device yet devised.  It produces the least distortion, and that distortion is predominately second harmonic, which is relative musical in sound.  By contrast, pentodes produce greater distortion, and the third harmonic tends to dominate.  A transistor generally looks like a very bad pentode.

To state the obvious, a single-ended circuit must be Class A1 or A2.  A push-pull amplifier may be Class A1, A2, AB1, AB2, B1, or B2.  Class A indicates that each output tube handles the full cycle of the audio signal, while AB and B allow some of the devices to cut-off during a portion of the cycle.  Subscript "1" indicates that no grid current is drawn by the output tube, while subscript "2" indicates that the output stage enters the grid current region of operation.  In the grid current region, the impedance presented to the driver stage is abruptly lower, and drive power is required, not just drive voltage.  The grid current region tends to be rather non-linear, and most designers will avoid it.  Single-ended and push-pull circuits may be built with triodes, beam power tubes, pentodes, or the latter two in ultra-linear ("partial triode") mode.

In a Class A push-pull circuit, there is a natural cancellation of even-order harmonic distortion products.  The cancellation is not complete, of course, but it would be unusual to see large amounts of second harmonic distortion from a push-pull circuit (Radiotron Designer's Handbook, 4th ed., 1954, page 571).

Applying this to the Renaissance Series, the circuit is strictly Class A1, and is push-pull with the exception of the very first 6SN7 triode, which operates under conservative conditions and is thus relatively free from distortion (Moir, High Quality Sound Reproduction, page 264).  This single phase splitter triode is interesting, in that the very same electron current flow creates the antiphase push and pull signals, which, given equal impedances within the amp (they are), match exactly.  As such, the signal is not being Cuisinart-ed as with most phase invertors, an objection voiced by many single-end advocates.

Note that a push-pull circuit has no significant ability to cancel odd-order distortion products.  If low distortion performance is required, one must avoid the generation of odd-order harmonics in the first place.  A good triode tube meets this requirement.

Three difficulties are encountered in the design of a single-ended tube power circuit.  Firstly, there is no mechanism to naturally cancel even-order harmonic distortions.  Secondly, significant new distortions may arise in the output transformer.  Thirdly, available power output is greatly limited in a single-ended design, such that it will be spending more of its time in overload for a given volume level.

For background, recall the old children's science project in which a length of wire is coiled around a nail and then connected to a battery.  The DC current from the battery flows through the coil to create an electro-magnet.  The primary winding in a single-ended output transformer is similar to this, and also creates an electro-magnet.  The full DC current for the output tube(s) flows through the transformer primary and strongly magnetizes the core of the transformer.  Thus, much of the core's ability to couple the audio signal is used up by the non-audio DC current, and causes the core to saturate asymmetrically with audio signals (Radiotron, page 247).  Even below saturation, this DC bias increases distortion, especially at low frequencies (Moir, page 283; Radiotron, page 217).  Adding parallel output tubes for more power directly increases the DC magnetization current, thus exacerbates the distortion problem, and requires that more primary inductance be designed into the output transformer.

To deal with this, a less saturable core alloy is often used, but this causes poorer coupling of the audio signal (Radiotron page 207).  Alternately, a large "air gap" may be introduced into the transformer geometry, which again causes aberrations in coupling.  In most cases, a greater amount of core material is used, which may in turn increase some low level (B-H) non-linearities.  The final result is either a higher degree of distortion (all harmonics with the second dominating, increasing with decreasing frequency), a measurably peaked frequency response, or both.

Radiotron summarizes, "...fairly high distortion has the effect of apparently accentuating the bass...It should be emphasized that this is not the same as true bass, and does not constitute fidelity"  (Radiotron, page 616) and notes that this trick was used "In small [radio] receivers, in which the loudspeaker is sometimes incapable of reproducing the bass" (Radiotron, page 676).

Since the distortion in the single-ended transformer is asymmetrical, a system based around this type of amplifier might be more sensitive to absolute polarity.

In a fairly complete summary of single ended output transformers, Duncan Kelly concludes, "Direct current is thoroughly undesirable in audio transformers" (Transformer Distortion, Audio, March 1959, page 44).

These problems do not arise in a push-pull amplifier, in which the primary  halves are oriented in opposing DC directions (Moir, pages 282-284; Radiotron page 207).  The DC magnetization force is thus canceled and is not an issue unless the push and pull output tubes are adjusted to draw different currents.  Any imbalance in DC idle current will lead to greater distortion at low frequencies, just as in a single-ended design (Audio Cyclopedia, 2nd Ed., 1969, pages 1449-1450).   The Renaissance Series maintain a high degree of DC balance due to the self-correcting nature of 300Bs under individual cathode bias.

Please note that the distinction between push-pull and single-ended Class A triode designs does not stem from the tube itself, but from the natural distortion cancellation in push-pull and from the transformer problems in single-ended.  Since a single-ended transistor amplifier may omit the output transformer, it may display yet another set of characteristics.

How the ear deals with the characteristics of a single-ended tube power amplifier is quite interesting.  The human ear is a non-linear encoder of information, and excess second harmonic blends in to form the impression of an additional sub-harmonic.  This technique was deliberately employed in small radios in the 1940's to create a richer sound, then referred to as "synthetic bass" (Radiotron pages 616, 676).  The Radiotron Designer's Handbook notes, "It should be emphasized that this is not the same as true bass, and does not constitute fidelity."

The frequency response errors of some single-ended tube amplifiers tends to create a high frequency boost and a low frequency cut, in one case approximately +/- 3 dB (Stereophile, Jan. 1994, page 108).  The subjective effect of the low frequency loss might perhaps be partially offset by the second harmonic distortion.

Earlier I noted that the triode could be the most linear of amplifying devices.  I left this small hedge because it is possible to build a rather flawed triode as well.  The 300B is a highly linear tube.  In fact, the high voltage supplies in the Renaissance Seventy/Seventy do not vary by one volt over the range from idle to clipping, indicating an absence of rectification effect (distortion).  The type 845 is also a very linear tube, although requiring higher drive voltages, which can result in more overall distortion.  The 211 is a bit more problematic; it requires a large drive voltage and drive power to deliver full output.  In such operation (Class A2) the tube is said to "draw grid current."  Entering the grid current region may cause a sort of crossover behavior as the driver stage is abruptly called to provide significant power into a suddenly lower impedance load (Moir, page 281; Ravenswood, Fixed Bias, Audio, Feb. 1958, page 48).  Amplifiers running subscript 2 operation often may be identified by the use of a power tube (2A3, 300B, etc.) in the driver position.  The 211 and 845 also require very high plate voltages (800-1200 VDC), about twice that of the 300B, and desire a higher load impedance, both of which complicate output transformer design.

It has been asserted by some contemporary designers that one can not hear second harmonic distortion of 10% to 20%, such as may be produced by some single-ended tube amps.  However, I find no corroboration of this, and in the Renaissance Seventy/Seventy hold the sum of all harmonic distortion, including the second, to approximately 2% at clipping without negative feedback.

It is also worth noting that multi-grid tubes, such as the KT88, connected as triodes often do not exhibit linearity comparable to the 300B, 845, or 211 tube types, although this connection may have some advantages over traditional pentode/beam power operation.

In any event, I do not think that THD as such is actually what we hear.  I believe that it shadows something that we do hear in the context of analogue tube equipment. As a case in point, there was a 1987 Journal of the Audio Engineering Society (JAES) publication of a study by Dolby Labs' Louis Fiedler, in which, if memory serves, .005% THD in a digital system was clearly audible to all listeners.  Several times this amount would not be detectable in a similar tube analogue set up.  Some other measurement likely will be found significant in the context of the a/d/a cycle, and will probably be meaningless when applied to tube amplifiers.  At the end of the day, the human auditory system is a marvelously arcane recognizer of patterns, and we are not able to mimic it with our test instruments.

Feedback is another interesting topic.  Traditional theory gives feedback high marks, but this analysis changes when we consider that the "error" signal is fed back into a non-linear amplifier.  Due to this, feedback may lower the overall level of distortion, but it also multiplies its order.  For example, if an amplifier naturally produces second harmonic, feedback will create a second harmonic of that second harmonic, which is the fourth harmonic.  If the basic amplifier has second and third, the fed-back amplifier will contain second, fourth, sixth, and ninth.  As is well known, the higher orders of distortion are more objectionable to the ear than lower orders, and odd orders more offensive than even orders.  Thus it may be possible to lower the level of distortion products and still have the distortion be more audible.

The application of negative voltage feedback also reduces an amplifier's measured output resistance, i.e., it raises the "damping factor."  Here again, the measurement fails to capture the essence of things. In the case of a feedback amplifier, better control of speaker motion is said to occur because the speaker's excess motion creates a voltage (the back e.m.f.) which enters the feedback loop via the amp's output terminals.  The amplifier then acts in a manner opposite the error signal to correct for it.  However, like many theories, this is an oversimplification and, in practice, the opposite result may be obtained.  There are several reasons:

1)   The motion of a speaker's voice coil former may not match the acoustical output due to cone break-up modes and room acoustics.

2)   The motion of the coil former is being sensed by the voice coil.  The coil is designed to be a good driver, but is a lousy sensor, primarily due to its high inductance, which will  create phase anomalies in the back e.m.f.

3)   The back e.m.f. may pass through a cross-over network, which will again alter phase and frequency relations.

4)   A differing back e.m.f. from another driver may be summed in via the crossover, making a composite signal that does not match either individual driver.

5)   The speaker leads may cause additional phase shifts.

By the time the error signal reaches the power amplifier it is arguably an erroneous error signal.  As the power amplifier attempts to correct for this signal, it may actually do the exact wrong thing with respect to the speaker's acoustic output.  Subjectively, I have noted that high feedback amplifiers tend to give the bass a one note boom on certain speakers, and tend to create an electronic glaze in the midrange, possibly attributable to this process.

With regard to damping, I suspect the best approach is to design the amplifier to have as low an output resistance as possible in a static sense and use little or no feedback.  As it happens, the minimum natural output impedance is obtained from a low mu triode amplifier (Williamson & Walker, Amplifiers and Superlatives, JAES, April 1954, page 79).

None of the foregoing is an endorsement or condemnation of any particular amplifier design.  The engineering information seems against single-ended tube amplifiers; to be fair, however, perhaps the added distortion offsets something else in the recording chain, at least under some conditions.  Then again, perhaps something we do not yet know how to measure something that is better with single-ended designs.  The critical ear will help provide the answer: if, for example, part of the sonic character of a single-ended design is attributable to excess 2nd harmonic distortion, then that amplifier will probably sound somewhat full, mushy, or thick, even on instruments that should be clean and fast.  This is the characteristic I perceive in such amplifiers.

Nothing made by the hand of man is perfect. It seems to me that the audio designer's task is to push the frontier of compromise as far away as possible, and then to balance the imperfections in a fashion that serves musical truth.

As we often say, in a battle between theory and the real world, the real world always wins. Or, as Daniel von Recklinghausen once said, "If it measures good and sounds bad, it is bad. If it measures bad and sounds good, you've measured the wrong thing."

Tube Audio at its Finest - If you’re in the market for a reference-level preamp, I heartily endorse auditioning the Signature IIa from VAC. It will take you a long time to exhaust its possibilities—it did me—and you may never find the end of them.
Garrett Hongo
Kevin Hayes has really outdone himself with the VAC Signature IIa preamp. A statement piece at a luxury price, it plays music with extraordinary finesse and drive, accurate timbres, spaciousness in the soundstage, swift attacks and aching decays, and an even spectral balance. Of all the preamps that have been in my system, it is the one that most wisely balances the ofttimes contradictory qualities of superior drive and great finesse. Completely versatile, it can be voiced by rolling tubes to suit just about any ear, has numerous inputs for a multitude of sources, can be fitted with an outstanding phonostage, and be run balanced or single-ended. It performed splendidly with three of my power amplifiers, both tubed and solid-state. Besides all this, it looks flat fantastic, a fancy piece of audio bling perched atop its own power pedestal.
I don’t know if Nicolaus Copernicus was eating oxtail soup, looking at an apple falling from a tree, or cleaning his astrolabe when he thought up his theory of the revolution of celestial spheres, set down in his book De revolutionibus orbium coelestium in 1543. But his superior insight, partly derived from mathematical expertise, changed everything, putting the sun at the center of the universe and not the earth, as most of the governing clergy insisted was the case at the time, and became the defining epiphany of the scientific revolution that followed. After Copernicus, clergy could no longer so readily dismiss a Galileo or a Giordano Bruno by saying, Are you gonna b’lieve me or your own eyes? Scientists came to believe in their own eyes— observation before theory the new motto. Likewise, I’m not sure if Alfred Wegener, a German climatologist and arctic explorer, was peeling an orange in 1915 when he thought—Hey! The coastlines of Africa and South America fit together! He may have just been working on a jigsaw puzzle, but, somehow, he came up with the idea of continental drift—that the earth’s landmasses were once one big supercontinent that then broke apart and moved away from one another, giving rise to the oceans and, some eons and eons later, a new revolutionary paradigm in geology. What is certain, though, is that, every once in a while, we get a shift in the way we think of organizing things, be it astronomy, geology, or fried green tomatoes. Stuff we start noticing just doesn’t make sense using the old way of looking, so we have to change the lenses through which we’ve been seeing as through a glass darkly, clean things up, and come up with fresh new approaches.
 
Kevin Hayes, President of Valve Amplification Company (VAC), has taken fresh approaches to preamp design at least three times since the inception of his company in 1990. I spoke to him recently and the discussion told me much about the “revolutions” in VAC preamps over the past twenty years. Rather than sitting back, practicing science of the caretaker variety and simply refining his existing circuits, Hayes has spent most of his R&D time “interrogating the gross flow of electrons,” identifying where the electronic turbulences are in each given circuit. He wants to see not only what might be improved by parts substitutions, but what entirely different approaches, new topologies, completely different flows of those electrons might bring. For example, in 1998, when VAC issued the aptly named Standard preamp, it altered the VAC lineup, shaking the sun and stars, replacing the original 1991 CPA-1 preamp, and staying in production until 2007—nearly ten years. But, the advent of the Renaissance Signature Mk I pre in 1999 marked a sonic breakthrough for VAC that introduced a new circuit topology—an extremely high-gain, three-stage line section with direct-coupled interstage and transformer-coupled inputs and outputs—and the reliable Standard was eclipsed (if not yet discontinued). Then, very quickly in 2000, Hayes released the Signature Mk II with major changes to 11dB gain and a fully differential circuit with transformer coupling at the inputs. It established yet another major shift in preamp design for VAC and stayed in production another ten years until the recent release of the Signature IIa.
 
Introduced in 2011, the Signature IIa represents the first new iteration of VAC’s flagship, transformer-coupled preamp in over a decade. It sports a small boatload of improvements over the prior Signature II. New are the volume control, key passive parts, variable phono loading, and the character of the chassis (better damping, new “energy termination” solutions). Also new is the option to roll tubes in the linestage.
 
That linestage has 12dB of gain, a frequency response claimed to be flat over the audio band, and an output impedance of 96 ohms. It comes stock with two 12AU7 twin triodes and two E88CC tubes (designed to be swappable). From input to output, the Signature IIa contains no coupling capacitors in order to protect the purity and detail of the hand-wired, direct-coupled triode tubes. There’s no loop negative feedback either, as Hayes wanted the output interface to be completely stable and free from dynamic interactions with an external load. The preamp does not invert phase.
 
As for the fully differential circuit, because the preamp achieves this through transformer coupling, there are fully balanced inputs and outputs. It also means the Signature IIa should sound the same with either RCA or XLR hookups. And, significantly, the transformer isolates the Signature IIa’s sources from the amplifier it is driving.
 
The optional, built-in phonostage (my review unit came phono-equipped) is zero-feedback, capable of both mm and mc operation with variable loading. Moving-coil loads are 470, 300, 250, 200, 150, and 100 ohms, while moving-magnet loads are 100x those. The mm phono is fitted with six 12AX7 triodes and is capable of 44dB gain. In mc mode, two wide-bandwidth transformers (sourced from Lundahl) get switched into the circuit, adding 20dB of gain passively.
 
I’ve been on a preamp quest for a while now, and, in my limited experience, what I’ve found is, features and superior technology aside, tubed preamps are basically designed to create weight and drive or else to have finesse and sophistication. If you look at their spec sheets, you’ll see gain levels that cluster either around 12dB or 20dB and this, generally, tells you what the preamp emphasizes. A gain around the lower figure would lead you to expect finesse über alles. Gain nearer the higher figure suggests tone and drive as foremost. VAC has made preamps in both categories (the Signature I even exceeded the “big on drive” category with a gain of 35dB!) and, given its 12dB gain spec, one might assume the Signature IIa to fall on the finesse side of the fence. And, at first, I thought so too, as, paired with my reference deHavilland KE50A mono amps (40Wpc), it did seem the Signature IIa had all the sophistication of my deHavilland Mercury 3 linestage—lovely with a gentle hand on orchestral music, able to resolve evanescent details and create a subtle, organic flow. But it also somehow sounded “light” to my ear, missing body on strings and sometimes voices, and so I ventured onward, pairing the VAC preamp with power amps that had more output and quickly discovered its strength, tonal weight, speed, serious authority, and ability to throw a big soundstage. The Signature IIa seemed to split the difference between my ad hoc tribes of preamps—or did it just combine the best traits of both?
 
Physically, the Signature IIa is one of the loveliest mechanical things I’ve ever seen. Though my review unit came in black (silver also available), that hardly begins to describe the illusion of depth in the glossy 10mm-thick faceplates of both the control and power units, glittering with gold metallic flakes embedded just under the layered lacquer finish. What’s more, both have as centerpiece an inset, backlit LED logo with the VAC trademark—an encircled lightning bolt beside capital letters spelling out “VAC.” Running underneath the logos are lines of understated gold script silkscreened on, identifying each. The bling-factor on the control unit is pretty high too, as there are two large, rakishly beveled, hand-sized gold knobs marked Volume and Selector, and four smaller outlying ones marked Monitor and Mute on the left, Cinema (for bypass) and Power on the right. Build-quality is superb and each aluminum chassis is finished with an even, flat-black powdercoat.
 
Around back, the preamp absolutely bristles with connectors. These are premium Cardas rhodium types that can stand up to a lot of cable swapping. There are four sets of main outputs, two RCA and two XLR; five line inputs, two with both RCA and XLR jacks; a set of RCA Cine inputs; a tape loop; a control knob for phono loading (if phono is fitted); and a set of mc phono inputs on RCA jacks (converts to a sixth line input if phono is not fitted); a selector knob for mm/mc; and a set of mm phono inputs (RCA). Below these connectors are switches for SE/BAL selection and for adjusting brightness or dimming of the logo. Because the Sig IIa has four sets of main outputs, you can readily bi-amp, either single-ended or balanced.
 
With the VAC Signature IIa, I used four different amps, two sets of speakers, and both balanced and RCA interconnects. For sources, I used analog, CD, and an iMac with a USB DAC. After an initial run-in period of scarcely 50 hours, the preamp distinguished itself in multiple and (I’d previously thought) contradictory areas—finesse, tonal weight, and drive. This preamp created musical momentum in ways that were both powerful and subtle. Add to this, the Signature IIa also demonstrated fine spectral balance and superb dynamic and timbral contrasts. In its performance, it transcended both gross categories of preamp I’d presumed existed. As I mentioned already, though it did not match perfectly with my moderate-power deHavilland KE50A tubed monos, the Signature IIa sounded great with three other amps—a VAC Phi-200 (100Wpc), Herron M1 solid-state monoblocks (150Wpc), and a VAC PA-100/100 (100Wpc). Compared to my reference combo of deHavilland KE50A tube monoblocks and Lamm LL2.1 linestage, the Signature IIa with Herron or VAC amps consistently sounded more polished, with better imaging and a wider and taller soundstage, reaching up to a yard on either side of the speakers and almost as high above them. Believe it or not, the Signature IIa sounded pretty much the same run balanced with Cardas Clear balanced interconnects or run single-ended with Siltech 330i or Cardas Clear unbalanced. As for speakers, both my reference Von Schweikert VR5 HSEs and a review pair of Von Schweikert VR-44s that arrived late in the review period worked terrifically well, with the powered subwoofers of the VR-44s providing more bass presence, detail, and slam. The remote operated smoothly during the entire review period.
 
Near the end of the review period, with the stock sound of the Signature IIa firmly in my ears, I started rolling linestage tubes. On Hayes’s recommendation, I first tried a pair of Philips E88CC SQ tubes manufactured in Heerlen, Holland. A toggle switch near the right tube socket sets the circuit for one of two types (8416 and 12DJ8; or 6DJ8/ECC88, 6922/E88CC), but since the Philips used the same setting as the stock tubes, I didn’t have to flip it. In fact, all the tubes I tried—pairs of Amperex 7308 PQ, Amperex 6922 PQ, Amperex Bugle Boy 6DJ8, Mullard E88CC, and Mullard E188CC (a 7308)—used the same switch setting. To my ear, the Philips and Mullard E188CC tubes sounded smoother, more liquid, sweeter on top, had more weight, and gave more detailed and longer decays than the stock tubes. The Amperex 6922 and 7308 tubes were more resolving than either, perhaps more balanced through the frequencies, and had superb top-end finesse and air—great for voices. The Bugle Boy 6DJ8s were also airy, but spacious, harmonically rich, and sensuous, especially on orchestral strings. Finally, the Mullard E88CC sounded even more spacious and warm—on the verge of “euphonic,” and, to my ears, mostly pleasing. But these weren’t game-changing differences to me, and I was nearly as content listening to the stock Chinese E88CCs.
 
Matched with a VAC Phi-200 stereo amp, the Signature IIa consistently produced a clean, punchy, and speedy sound that was never hard-edged. On most orchestral pieces, notably Alfred Brendel’s CD of Mozart’s Piano Concerto No. 12 in A Major, K414 [Philips], strings were sprightly and airy but authoritative when called for. There was an inner liquidity to piano notes. Attack transients were exceedingly fast, just on the pleasing side of sharp, and I experienced no fatigue. Interior shadings—the notes as they developed—were completely natural, evolved in time, and breathy with life. On Brazilian Dreams [Manchester Craftsmen’s Guild] by Paquito d’Rivera with the New York Voices—a CD I’ve used as a demo at shows—I heard, on tune after tune, an amazing clarity, precision, and punchiness without any etch or analytic quality to the male and female voices, brass, and d’Rivera’s agile alto clarinet. I heard more detail and my listening seemed more alert and lit up.
 
Even with amplified music, the Signature IIa, consistently demonstrated an ample sensuousness as well as excellence with timing, detail, and finesse. Austin’s been the town for live rock for a good couple of decades now and Jimmy Lafave has been one of its local heroes. His live CD Austin Skyline [Bohemia Beat Records] is a treasure. When I spun his cover of 60s hit “Walk Away Renee,” LaFave’s electric rhythm guitar and Larry Wilson’s lead both produced ripe, ringing tones with tasteful plucking and light sustains. Reacting to LaFave’s rough-edged and plaintive veteran wailer’s voice, tinged with smokey shadings, Wilson bent out a clear and bluesy solo, full of aching lamentation. His fills made for open, airy, and privileged interplay with LaFave’s deft frailing and strumming, producing a seamless, sparkling electric tapestry. I noted the drumming had march-like, doublethunks from the kickdrum and that the electric bass was subtle, unobtrusive, and tight. And the organ stayed in the background, too, gently comping and undergirding the whole sonic field until the final choruses, when it emerged and claimed the tune as a dirge. Each of the band’s light crescendos came with a gently rising momentum, making for a succession of sonic swells that captured the ambience and clarity of this live club date.
 
When I hooked the solid-state Herron M1 monoblocks with their 220k ohm input impedance to the Signature IIa, they were absolutely no sweat to drive. The system sound became warmer, more “tubelike” actually, with more emphasis on the smooth midrange, lovely scaling, and an even more organic flow to the music. Turning to analog, for example, I dug out my stereo LP of Yevgeny Mravinsky conducting the Leningrad Philharmonic Orchestra performing Tchaikovsky’s Symphony No. 6 in B Minor, commonly known as “Pathétique” [DG]. I used a ZYX Airy 3 cartridge (0.24mV) and clicked through the resistive loading options of the mc phono, adjusting the convenient dial on the left of the back panel for ragged violins and tinges of grey in the treble, trying to find the most clear, sensuous, and dynamic sound. On this and other LPs, I seemed to set the load either at 150 ohms or 200 ohms. On Adagio-Allegro non troppo, the first movement, there were gorgeously dark and delicate shadings from the violins at first and big, dark notes from the bass viols. I got a big soundstage, the scaling was impressive, and where came the movement of the theme from the second to first violins, it was a sweet and gentle thing that gave a real sense of spaciousness in the orchestra. Languorous passages with solo oboe fell away to a septet of woodwinds, then pianissimo brass fanfares. Later, there were sudden bursts of orchestral energy, quick turns of pace, and occasional splashes of brass turning to crescendo. The tonal richness of cellos and basses contrasted with the gentler shadings of violins and the piercing sweetness of a clarinet. The abundance of complex orchestral gestures and motifs, the alternately grave and dashing movements of the theme, all showed Tchaikovsky’s orchestral painting at its most tragic and complex, attesting to the Signature IIa phonostage’s sophistication with dynamic range and multiplicities of timbre, showing its breadth of power to communicate Tchaikovsky’s rich flows of momentum and tides of psychological expressivity in orchestration.
 
The phono also performed with wonderful tonal weight, detail, and timing via its mm inputs with my Ortofon GM Mono Mk II SPU cartridge (3.0mV). Dave Brubeck’s “Blue Rondo à la Turk” from the immortal Time Out LP [Columbia] spun with speedy, sparkling highs from Brubeck’s piano. There was a propulsive momentum with drums, bass, and piano tripling in unison on the famous theme. Paul Desmond’s alto sounded cool and sweet with small dynamic explosions. When Joe Morello hit the fan of his ride cymbal repeatedly, punctuating the rhythm, the sound shimmered out in time with the beat. But when he hit the cap, the cymbal rang like a damped cowbell. The Signature IIa with the Herron monoblocks created a sound that had real living presence to it.
 
Finally, I paired the Signature IIa with my VAC PA-100/100 stereo amp (based on the 1947 Williamson circuit). This sound was always rich and resolving, particularly suited to voices and strings. Returning to digital playback, I selected a piece of Baroque sacred music that never fails to move me. Its 13th century text is a sorrowful hymn to Mary set by Giovanni Battista Pergolesi in 1736. I’ve numerous recordings of it, but I chose Stabat Mater: A Tribute to Pergolesi [DG], a recent CD I ripped to Apple Lossless on my iMac’s hard drive running Leopard 10.6.8 and played back via iTunes (10.5.3) and a JoLida Glass Tube DAC. With Anna Netrebko (soprano) and Marianna Pizzolato (contralto) singing with the Orchestra dell’Accademia Nazionale di Santa Cecilio directed by Antonio Pappano, the title tracks opened with a beautiful duet, Stabat Mater delorosa, interweaving vocal parts but offering distinct timbres between singers. Pizzolato’s contralto was at first smoother, more liquid, sometimes with a slight stylistic thickness in her throat. She sang with rapid tremolos and brilliantly suspended topnotes that spun out over a conjunct bassline. Netrebko’s soprano sounded thinner, but much more agile, and, partly because of the close-miking, partly due to the Signature IIa’s resolving abilities, I heard very subtle shadings of grief and passion in her voice as she addressed herself directly to Mary mourning the death of Jesus. I found this level of detail extremely touching and appropriate to the somber dignity of the music. And the Baroque violins, played without modern vibrato to sweeten the sound of the bow crossing the strings, nonetheless sounded rich, lush, and detailed.
 
Through the rest of the eleven movements, both singers had numerous shifts of vocal intensity—moderate volumes rising to full-out song, then whispering, and full-out again with passionate topnotes held a good long while, attesting to the system’s power. And when they sang together, there wasn’t just a layering of their voices, but a thrilling intensity too, as they reached dramatically, with precisely differing timbres and vocal registers, for volume and harmony together. The system with the Signature IIa preamp sang along, never ragged or harsh in the difficult sustained topnotes and dynamic peaks, always producing a clear and emotionally compelling sound sensitive to all the glorious subtleties of this superb vocal performance.
 
Kevin Hayes has really outdone himself with the VAC Signature IIa preamp. A statement piece at a luxury price, it plays music with extraordinary finesse and drive, accurate timbres, spaciousness in the soundstage, swift attacks and aching decays, and an even spectral balance. Of all the preamps that have been in my system, it is the one that most wisely balances the ofttimes contradictory qualities of superior drive and great finesse. Completely versatile, it can be voiced by rolling tubes to suit just about any ear, has numerous inputs for a multitude of sources, can be fitted with an outstanding phonostage, and be run balanced or single-ended. It performed splendidly with three of my power amplifiers, both tubed and solid-state. Besides all this, it looks flat fantastic, a fancy piece of audio bling perched atop its own power pedestal.
 
If you’re in the market for a reference-level preamp, I heartily endorse auditioning the Signature IIa from VAC. It will take you a long time to exhaust its possibilities—it did me—and you may never find the end of them. That is, not until Kevin Hayes next cleans his astrolabe or peels an orange.
 
For anyone looking for true reference level amplification, the VAC Sigma 160i may well put an end to your search. I give it the highest possible recommendation.
Audio Forum members comments

The charcteristics of the Sigma is going to sound cliche but imagine mating the best characteristics of solid state....crisp snappy bass with the best of tubes, smooth articulate mid range with gorgeous highs. I have about 500 to 600 hours logged so far and it keeps getting better.  The phono stage is terrific.

09-10-11: Ghasley
Mwilliams, I am the proud owner of a VAC Sigma 160i amp mated to a pair of Wilson Audio Duettes. The 160i is simply stunning. I will try to describe for you. My recent amp journey was a Naim Supernait, then to a VAC Phi 200 driven directly by a Berkeley Alpha DAC, now the Sigma.
 
The charcteristics of the Sigma is going to sound cliche but imagine mating the best characteristics of solid state....crisp snappy bass with the best of tubes, smooth articulate mid range with gorgeous highs. I have about 500 to 600 hours logged so far and it keeps getting better. The phono stage is terrific. This is the amp Kevin Hayes has in his home.
 
This amp is NOT bloomy at all.....it has prat, snap, excellent bass and it is very romantic sounding without going too far. I have installed NOS Mullard 12ax7's in the phono section and NOS 12au7's in the input stage, all other tubes are stock from VAC. Everyone has different value judgements but I believe this integrated is fabulous and it has ended my search. My setup is presently a REGA P5/Exact2, Playback Designs MPD-3/Mac Mini, Vac Sigma 160i, Wilson Duettes (no sub, doesn't need one in my largish room), Running Springs Jaco. cabling is Cardas Clear Light interconnects/Speaker Cables, Cardas Clear M power cables.
 
Seek out a demo, Every dealer i spoke to about it prior to my purchase was quite effusive about the sound (when are they not!) yet I have to agree.

Good luck
.......Ghasely.

I heard the VAC Sigma 160i at RMAF last weekend. It blew me away. I ran it through all my demo CDs and a few of the LPs they had there. I went back to the room twice. I probably spent at least an hour total listening to this setup (nicely matched with Tannoy Definitive T10 speakers).
 
I have an Art Audio Vinyl reference, Joule Electra LA-150 MkII, and Genesis M60 monoblocks and have been totally delighted with that combination. The 160i has me seriously thinking of going to integrated. 
 
The 160i at RMAF had the MC phono section and I was doubtful that it could be equal to the best separate phono pre. My doubts were dashed. Kevin has designed a tour de force for the vinyl lover. 
 
The amp is detailed but liquid and smooth and the bass is completely authoritative without any bloom.
 
The VAC 160i, simply put, makes beautiful music
.........Ikkyu2
 
Well a week or so after my earlier reply to this post, I took the plunge and purchased the Sigma 160i with MC phono and balanced input.
 
Break-in was about 220 hours (including the 50 hours it gets before leaving the VACtory). It has about 300 hours on it now. I put a pair of NOS Mullard 12AX7's in the phono section yesterday. It is hands down as good as my Art Audio Vinyl Reference (both using Lundahl transformers). 
 
The balanced input gives more transparency and dynamics than the RCA inputs when used with a studio master tape recorder (Otari MTR-15).
 
The bass is solid-state deep and taught and the power and neutrality are superb. It is plugged directly into a 20 amp dedicated circuit with a Shunyata Anaconda Helix power cord. I use the Hi-Fi Tuning fuses in all my gear and bought the 5A Supreme fuse for the 160i.
 
I hesitated long and hard in going the integrated route because I was very, very happy with the music made by the aforementioned Vinyl Reference with Joule Electra LA-150 MkII preamp and Genesis M60 monoblocks. I have absolutely No Regrets musically, financially, or aesthetically!
 
The VAC integrated allowed me to get rid of three HRS isolation bases, three expensive power cords, and two pairs of reference interconnects - an investment about equal to the separate components. My music room is a whole lot less cluttered-looking to boot.
 
For anyone looking for true reference level amplification and who has speakers that can be driven with 85 tube watts per channel, the VAC Sigma 160i may well put an end to your search. I give it the highest possible recommendation.
.........Ikkyu2
 

As a matter of fact, I liked it so much tooo that I bought the VAC 160 (w/MC phono and bal options), Tannoy DC10Ts aI plan to add the new Clearaudio Ovation Wood table , 

I rcvd my Vac 160I two weeks ago and have about 100 hours and another 100 hours to reach full break in. 

 
It's a beautiful sounding amp with amazing body and weight to wood instruments and holographic imaging. You would think live performers are in your house

...............Jim

I have had my VAC 160 with optional MC Phono and Bal input for about 6 months now. I am thoroughly satisfied with this purchase and enjoy using it every day - no buyers remorse or interest in looking for anything else. I have a very nice digital setup with Macbook and ARC DAC8 that I enjoy for many reasons, but I have to say the synergy using the VAC MC phono is more compelling to me than any digital I have heard or owned. 
 
Although relatively new to vinyl, I find I listen to it much more often than digital now with this system. I have never heard anything better at this price point and I think that it probably competes well above its class. The simplicity and reduction in the number of boxes and cords is a bonus for me, but the magical sound of this combo is what lures me back to listening more than I have in the past with other systems. 
 
This hobby is very individualistic and we all have different preferences and priorities but I would suggest, without reservation, an audition to anyone looking for a high end integrated to see if you like it as much as I do.
...............Jgc

As amps have come and gone, the Phi 200 has remained.......their quality, reliability and unimpeachable sound earn them a resounding recommendation.
Doug Schroeder - Dagogo

Kevin is among the most well read, technically informed tube preamp and amp manufacturers in the entirety of the high-end two-channel world. He is not so concerned with analyzing specifications to death, but rather what works in terms of obtaining the best sound. This review is my most comprehensive to date in terms of an amplifier’s use with other components. I subjected the Phi 200 to more sources, preamps, cables and speakers – systems – than any previously reviewed piece. It yielded top-quality sound with a large body of available components. Kevin’s concern is producing a quality instrument above all. You are paying him for the best amp he can build, and he’s going to make sure you get it. That is why he’s going to listen to it before it ships.

My experience with the Phi 200 is that I can be assured that no matter which loudspeaker I put into the rig I’ll get top quality sound. 

The Phi 200 is a natural winner when it comes to symphonic and chamber music. The flush tonal quality of natural instruments created by the Phi 200 enlivens a score. The Phi 200 is exemplary in capturing the surge of the symphony as it crashes in crescendo, emulating the killer waves of the ferocious hurricane.

The VAC sound is audio-writ large but properly proportioned; it is elegant, opulent and ebullient. The vastness and spatiality of the soundstage with the Phi 200 is quite surprising when heard for the first time. You may have heard many amps with differing power resources, and different levels of clarity. If you have worked primarily with solid-state amps, you likely have not heard the expansiveness a fine tube amp can bring to a system.

Pay Not To Play
I would pay good money to have Kevin Hayes, owner and designer at VAC, listen to an amplifier. If you purchase a Valve Amplification Company product you are paying Kevin to listen to your product extensively before you use it, and you should be elated. He listens to everypiece of gear which leaves VAC’s premises. Again, it is Kevin who listens, not some other worker. He is the final arbiter of sound quality on every piece of VAC gear which is sold. It is a very good thing when a knowledgeable, passionate person is at the helm of an audio company and singularly treats your component as if it is his. That kind of personal service costs more, but brings some distinct advantages to the audiophile searching for top sound.
 
Kevin is among the most well read, technically informed tube preamp and amp manufacturers in the entirety of the high-end two-channel world. When he was a teenager he pored endlessly over a tattered copy of the Radiotron Designer’s Handbook, and remarks that he has, “… collected and read thousands of pieces of literature on the creation, capture and reproduction of sound.” In describing this he states, “I don’t know why God gave me this passion for music and its reproduction, but it’s been part of the fabric of my being for as long as I can remember.” I can relate to that sense, as when I was in grade school I was already glomming onto a 1977 Lloyds all-in-one system (8 track, turntable and receiver), and shortly after assembled my first rig. I also have felt driven to assemble stereo systems in a search for “musical meaning” in sound reproduction. Consequently, this article brings together the deep desires of two men intensely searching for as close to musical perfection as can be achieved in an audio system. Kevin spends an inordinate amount of time listening to a piece of equipment until he deems the design worthy. I have listened to an inordinate amount of gear, looking for the perfect sound. That search for perfect sound has led me to VAC.
 
Transformation of An Audiophile
In younger days, while Kevin was developing into a tube amp impresario, I was not so passionate about tube amps. I came of age during the ascendancy of solid-state technology and was inevitably swept up in it. When I began to assemble stereo systems I was convinced that solid-state trumped tubes on principle. I made the same assumption as thousands of music lovers; the smaller, cheaper, newer technology had to be better. How simplistic that viewpoint was!
 
Lurking in my mind was a misperception that, in some respects, still plagues the populace – that anything arising from an older technology was suspect of being inferior. Perhaps you have witnessed a person who sees a tube preamp or amp declare, “Tubes! I didn’t know they still made audio equipment with tubes.” Unless a person consumes Hi Fi periodicals, visits the right dealer or internet forum, or attends a Hi Fi show, the bias is likely to remain. Tube amps still seem on the face outdated to many and are treated as suspect devices by others. I see comments on audio sites from individuals who approach tubes as though they are inherently untrustworthy, as if they degrade sonically so quickly and have such poor distortion specs that one can’t be certain of their performance. To such individuals, solid-state is nigh unto infallible. I was like that for a long time. Part of it was that I was not into DIY, and could not afford finer tube gear; part of me wanted to believe that I sacrificed nothing sonically for sticking with solid-state because on the whole it was cheaper.
 
Over the years I have slowly been remade as an audiophile, morphing from a staunch solid-state supporter to a tube amplifier enthusiast. With growing experience hearing tube amps in quality systems, I was forced to admit that they have as much, and in some instances more efficacy than solid-state designs. I now find that I am drawn toward tube amplification like the proverbial moth to the flame. I am increasingly using tube preamps and amps in systems by preference.
 
During this process I have also revised my thinking in terms of use of tubes with less efficient speakers. Experience with the amp under review here, the Valve Amplification Company (VAC) Phi 200, has cemented my belief that solid-state is not the only game in town for electrostatic and magnetic planar speakers. In fact, paying attention more to the timbre of the music, a strong argument can be made that tube amps are the ideal for panel speakers; jacking up Watts is certainly not the only variable in attaining a pleasing result with panels.
 
Tubes and TUBES
There are tubes, and then there are some: not all tube amps are created equally. When approaching tube amplification one must determine early on which direction will be taken, the low-power linear circuit topology such as SET (Single-Ended Triode) amps, or larger high-output power stages with push/pull topology and a battery of output tubes. There is an alluring attribute of clarity in many of the simpler, lower power amps which is difficult to match in the higher-powered designs. With economical tube amps, one usually has to make a trade off, purity for power, or vice versa. It is rare to find both in abundance.
 
Having used both types I have at this time concluded that I prefer to trade an extremely small amount of clarity for radically increased power. Ideally, I would never have to do this, but I found myself longing for dynamic power and weight when hearing low-power amps. They simply have a tendency to sound wussy compared to higher-powered tube amps, even when paired with extremely efficient speakers. The search for ultimate-sound low-power amps radically limits the number of speakers to be practically considered, a trade off that I am not willing to make.
 
Given that a system is influenced in terms of signal purity throughout the chain, I determined that I would sacrifice marginally at the amp when it came to clarity and make up the deficiency in the other components, particularly the source. I have found the ability of an amp to create robust dynamic power an aspect too important to skimp on; but the sense of clean power can be enhanced through careful selection of attending components, especially the source and cabling used with the preamp/amp combo.
 
Let it not be misconstrued that I am advocating any intentional lowering of standards in sound quality. When confronted with real-world limitations and budgets for gear, one simply must make choices leading to the best result. In no audio system is there an absolutely perfect route to ideal sound; there are always trade-offs. I seek to trade off the potentially most damaging shortcomings for ones which are potentially least damaging. A good example is the use of power conditioning components, which invariably involve a trade-off of absolute clarity as they extend and complicate the system. One must assess whether the influence of the conditioner is overall a positive or negative.
 
At this point in time I do not typically use power conditioners in systems, as I find that every one I have used has degraded the clarity of the system in an absolute sense. I am the first house in our subdivision and the power transformer sits right outside our back door. I have clean, noise-free power lines and despite trying many power devices which utilize filtering I have always ended up returning to the good ol’ plug-in-the-wall method. This does not mean power treatment is without merit, but simply that I do not benefit greatly from it. Thus, the elimination of the power conditioner improves the overall system clarity and the amplification benefits.
 
A very practical consideration in terms of speaker selection also necessitated this decision to settle on big amps – I enjoy huge panel speakers. These are typically difficult to drive, effectively sidelining smaller tube amps. One possible panacea may be the gain feature of the Ayon Audio CD-5, an extremely fine all-in-one player/preamp, with settings of 4, 6, and 8 Volts output. With it, one has the option of matching smaller amps with less efficient speakers. Save for that indulgence, necessity exists to have ample power to drive a 2-ohm load, and sometimes much lower, typically found in larger panel speakers.
 
Love Affair with Panel Sound
My first experience hearing a panel speaker was in St. Louis at a high-end shop where, shamefully, I cannot recall the name, I was overwhelmed by the majesty of the Magneplanar Tympani. I never dreamed sound could be like that! Over the years I have had the pleasure of hearing a wide variety of pleasing panels. I flipped speakers annually, if not more often, and found myself bouncing between dynamic and planar offerings. In recent years I have been migrating toward full range ESL (Electrostatic Loudspeaker) technology and have adopted the King Sound The King as my reference. Recently, I added a new version of the hybrid dynamic speaker from Legacy Audio, called the Whisper DSW. The Whisper utilizes a 4” magnetic planar midrange, so it also gravitates toward panel sound.
 
As my reference speakers have been upgraded over the past decade, so also has my amplification. In that process, I have expanded from the solid-state end of the amp spectrum to hybrids, to tube amps. This was quite unexpected for someone sold on the merits of solid-state. Once I learned that powerful enough tube amps existed to do the job, I thought that they were all priced into the stratosphere. Wrong. I ended up settling on the compromise position – tube hybrid amplification. My affordable favorite is the capable and beautiful pair of Pathos Classic One MkIII amps operating in mono mode.
 
Of late I have been on a search for a premier amplifier to drive either the DSW or the King. This is no small feat; the Whisper, though having four 15” bass drivers per channel and 95 dB sensitivity is a 4-0hm speaker and an open baffle design. Consequently, it is rated at 22 Hz – 30 kHz +/- 2 dB. It hits 20 Hz comfortably, but to extract larger subwoofer-like bass from it requires an amp with not just enough watts but also higher current. To get both of those in a tube amp usually costs much more than a solid-state amp.
 
On the other end of the speaker spectrum, the Kingsound King is a tough-to-drive electrostatic. It dips to approximately 1.8 Ohms at 20kHz, and though it has a more friendly nominal impedance of 6 Ohms, sensitivity is at 83 dB. These two speakers could hardly be more different from each other! It did not take long to learn that solid-state amps, while providing ample power, introduced problems in terms of sounding technical with one or the other speakers. The Pathi took me way down the road toward perfection with both speakers, but the ultimate answer was not to come until the VAC Phi 200’s showed up at my door.
 
Four lumps of amplification, please!
There are people who take their coffee black and strong. I take my amplification big and strong. Amplification junkies break down into two types; stereo people and biamp/mono people. I’m the latter. Usually, if you give me a speaker with two sets of binding posts the following thought takes possession of my mind immediately, “Four posts… which cable will I bi-wire with and which pair of amps am I going to use?” I have done so many comparisons of amps running stereo compared to passively bi-amped and bi-wired, or actively bi-amped that I no longer wish to assemble my reference system with just one amp. (So sad. Same here. –Ed.)
 
From the time that I first heard the King at CES 2008 and learned that Kevin used it in voicing the Phi 200, he suggested that I might use the amp with the speaker. Later, as I had taken ownership of the speaker, the possibility that I not follow up with a review of the Phi 200 was unthinkable! Seeing that only one unit was driving the speakers at the show, I assumed that one would be sufficient for the review. Kevin offered that two would be superior. But of course! Now that’s impressive; a manufacturer who offers a second amp to get the reviewing job done right! I had seldom encountered that level of commitment to me from a manufacturer in setting up a review system. It speaks volumes to me about how Kevin is only happy when the sound is correct. The suggestion revealed to me that Kevin is keen on obtaining the optimal sound, and had confidence that his amps would perform at an extremely high level in mono mode.
 
At the first California Audio Show, the King was shown with the VAC Phi 200 to much interest and approval. There was a technical issue, as only one Phi 200 drove the pair of speakers but was using the 8-ohm posts versus the anticipated 2-ohm posts. Consequently at higher listening levels the amp was pushed to its limit and did not sound as effortless as it is capable. In my listening at home, I have tested all three settings, 1-2 Ohm, 2-4 Ohm, and 4-8 Ohm, and the King was much more controlled by the Phi 200 with the lower 1-2 Ohm terminals in use. The Phi 200 is the kind of amp that one can play a speaker like the King with confidence in stereo mode and work toward a second unit to operate them in mono mode for ultimate performance.
 
In extended use, the Phi 200 does not run terribly hot; I was surprised at how little heat they generated. The Cambridge Audio Azur 840W, a solid-state design, throws off more heat. Only if left on half a day in a smallish room would I think that they might test the limits of the listener’s temperature-comfort tolerance.
 
Unveiling the Phi 200
Perhaps the term unveiling is too strong; I’m here discussing the unpacking, appearance and operation of the amp. “Dis-crating” a high-quality amp can be a bit like the dance of the seven veils, as each layer is carefully stripped away. Surprisingly, no crate was involved; custom foam pieces cradle the amp in a sturdy double box. The casing and transformer covers are nearly of military thickness, fronted by a slab-like faceplate. As a side note, custom formed foam packing pieces are quite expensive. At the time of the delivery of the Legacy Audio Whisper DSW, I was about to toss out an indistinct smaller foam piece perhaps half a meter long which was lying nearby as the transport materials were being collected. Doug Brown of Legacy Audio requested its return, “You wouldn’t believe how expensive these are!” MSRP on the piece of foam – $30. No wonder manufacturers charge hundreds of dollars for a pair of OEM boxes with foam! Take note, owner, as it can save you serious money to save the packaging.
 
I chortled when I saw daisy chained rubber bands holding a very low tech piece of cloth draped over the thick aluminum face plate. It certainly did the job, as each amp was immaculate. Kevin will not spare a buck to attain ideal sound, but he’s sensible when arranging packaging. He’s not hung up on glam boxes as pretty velour bags inside wooden boxes don’t get the right sound out of a machine. I’ve learned to be less impressed by such things as I work with equipment. Don’t get me wrong, as a thick covering can save a component from shipping damage. I’ve seen more than one speaker’s finish impaired due to flimsy protective transport coverings. Just don’t make the mistake of thinking, “Oooh, high grade bag! This xxxxx has got to sound great!” Some components have great bags and merely acceptable sound. The Phi 200 arrives as a ruby concealed in a paper bag.
 
In terms of finish, black and silver are the two standard VAC colors, but beggars can’t be choosers, so while the Signature Preamp Mk 2 that I reviewed in March 2010 is in graphite color face, the Phi 200s features metallic silver gloss front plate. No matter, VAC gear looks rich and refined with nice, complementary hues. As the Einstein “The Light In The Dark” had a low-profile chassis, so also does the narrow chassis of the Phi 200, in a powder coat matte black finish that is uninterrupted, save for the tubes and backing wall of transformers. Sitting just behind these blocks of impedance transforming windings are the main operational switches.
 
One needs to be careful when handling tube amps as the weight is not necessarily evenly distributed across the chassis’ expanse. Wherever the transformers are, there most of the weight will likely be. In the case of the Phi 200, one must grab the amp nearly at the rear, literally picking it up at ¾ of the way to the back of the unit to prevent it from potentially slipping from one’s grip. It is a good habit to test-lift tube amplifiers to find the balance point. You do not want to be in the middle of transporting one and finding that you chose the wrong place to grab. It’s a scary feeling to have a component turning in your hand because its mass is unevenly distributed. Go about such tasks diligently and save yourself some fear or heartache.
 
Also on the top of the chassis, just in front of each pair of low-level voltage amplifier/phase splitter 6SN7 tubes, are small toggle switches allowing for selection of balanced (XLR) or single-ended (RCA) inputs. Nearby are corresponding holes for the output tubes in the chassis about the diameter of a pencil. These allow access to the bias adjustment points of the amp. A supplied small biasing tool akin to a tiny screwdriver is employed for adjustment of the bias. Behind each KT88-SC kinkless tetrode output tube is a small amber LED for assessing the biasing. This was a painless process as the controls to perform the operation are within easy reach and sight. You may have heard complaints of biasing tube amps being a PITA, but with the Phi 200 it is almost effortless. Using the tool supplied one turns the adjustment until the point at which the LED lights up. Then it is turned back until the LED just turns off. This requires slight movements; no lummoxes need apply.
 
When first installed, one has to baby sit the amp for several bias adjustment steps after the unit is first turned on respectively for 60 seconds, 90 seconds, two minutes, five minutes, and finally after 15-30 minutes. Biasing is also required whenever a tube is changed, and approximately once per month of usage. I found the amp to hold its bias extremely well. I would check often and end up not touching the settings as I could not determine that they had changed. The manual states, “Proper setting is indicated by an LED that is dark when no music is playing, but lights ‘with the beat’ as music is played.” The owner is left to determine how “heavy” the beat is to be. I put on some music with stronger bass line to adjust the bias such that the LED is never off completely but winks almost out before being illuminated by the next beat. When listening to Rapcore or Doom Metal music the light never turned off. Just kidding; I don’t listen to these genres of music.
 
The connections behind the transformers include 15A IEC for power cord, twin sets of binding posts for left and right channels, each having a common/ground post and three posts for 1-2 Ohm, 2-4 Ohm, and 4-8 Ohm to select placement of the positive speaker lead.
 
Phi foibles
There is an aesthetic consideration in the appearance of the Phi 200 which reveals itself when you hook it up; the inputs are behind the transformers, on the top of the chassis. My first reaction is that of appreciated sensibility; it’s far easier to see what you’re doing when setting up the amp than leaning over its side especially if the amps are in an amp stand! Officially, it was done to keep the front-to-back dimension within the space allowed by some cabinets and racks. However, it’s not so captivating to see the mongo power cord arc in the air because it’s too thick to lay flat emerging from the amp’s top mounted IEC receptacle. However, I will gladly endure this slight visual perturbation to use the Phi 200. I weep for any man who can afford this amp and whose wife kills the purchase because the power cord arises into the air. The amp is good enough that I would suggest offering new furniture as compensation. If you have stiff interconnects, they, too, will stick up in the air. If that is a problem, then consider getting longer interconnects and hiding the amps behind the speakers, a tactic which may get you noticeably improved sound.
 
The only other operational quirk I found was the fairly close spacing of 0.75-inch of the Cardas rhodium binding posts, the spacing provision of which is controlled allegedly by the insulation parts supplied by Cardas. Cables with oversized spades are placed too close to be casual about hooking them up. Though it didn’t always appear to be, there was enough room for spades of all cable types used. I made sure to use a binding post wrench, available from Audioquest and Cardas, to prevent possible slippage of the spades.
 
Reading required
Even an Owner’s Manual can reflect on the nature of the designer. The Phi 200’s manual describes features and has no diagrams. It is anticipated that someone who lays out long green for a premium instrument will care enough to read what and what not to do with the amp. Hence, a thorough discussion of the operations in the manual, a walkthrough if you will, describes the experience of using the Phi 200. Starting with the safety notices on the first page, tidbits of advice assist the new owner, among them:
 
Avoid power conditioners that float the ground pin.
A 12V trigger cable can be used to turn the amp on and off via external device.
“Pay close attention to power quality, and be aware that different power cords can alter the sound.” (Bravo! An amp manufacturer who acknowledges the critical nature of power cords!)
Discussion of break in period – approximately 200 hours.
Description of the appearance of tubes operating normally, as well as ones which are “running away”, being destroyed due to excessive current when seated improperly or defective.
Expectations regarding tube life and quality, and VAC selection of its tubes for use with the Phi 200, as well as a list of equivalent tube numbers for tube rolling.
Explanation of Impedance Matching, including the option of using two different impedance output posts for bi-wiring speakers (However, use of 4-8 Ohm posts are required for Mono amp mode with low efficiency speakers like ESLs).
 
As one reads, it becomes clear that Kevin anticipates the new owner to consider his amp an instrument for fine music reproduction. Years of experience as a designer and music enthusiast are coalesced into the Manual, and I recommend careful reference to it.
 
“VAC Facts”
Before delving into discussion of the sound of the Phi 200, I would first like to stimulate your intellect as to the quality of the Phi 200 and VAC gear in general by alluding to what I call “VAC Facts”. These are lesser known packets of knowledge regarding development of the VAC Phi 200 amplifier. These VAC Facts are not merely for entertainment; they are stepping stones to understanding the radical commitment of Kevin Hayes and VAC to bring you the ultimate in audio componentry. Good sound needs to rest on good design principles and good execution. The VAC Facts speak to these and beckon rationally to those who are seeking ultra high-end electronics. As you read them, these testaments to quality will lead you to conclude that VAC authentically cares deeply about product integrity and sound quality.
 
VAC Fact: The Phi 200’s name is not mysterious, as Kevin merely followed convention in audio circles by using a letter of the Greek Alphabet. It may not be an exaggeration to say that half the Greek alphabet has been sourced to name audio components and technologies.
 
VAC Fact: The company builds “Stereo Beam Power” amplifiers. This is a reference to avoidance of standard Tetrode tube designs. According to Kevin, a “beam tetrode” or “kinkless tetrode” causes the electrons to flow in sheets or vertical beams, while repulsing secondary electrons. The design allows for removal of the third grid inside the tube, leaving the anode and cathode. The design is more efficient and yields greater power output than a pentode tube. The KT66 and KT88 are the most successful implementations of this technology in terms of audio quality.
 
VAC Fact: The Phi 200 is a proudly hand built American product. However, it uses a new twist on the power tube, the KT88-SC. Chinese tube maker Shuguang makes it and the 6SN7, both of which are deemed better than NOS tubes! Kevin states that they are notable not only for superb sound, but superior longevity as well.
 
VAC Fact: The Phi 200 was introduced at the 2008 Rocky Mountain Audio Fest (RMAF). Two revisions have been introduced, namely the addition of the MONO switch, and a LOGO ON/OFF switch.
 
VAC Fact: The KT88-SC power tubes operate in ultra-linear mode and feed two 15-pound VAC output transformers based on classic transformer design.
 
VAC Fact: Kevin adheres to a “divide and conquer” philosophy when designing higher-power amps. Per Kevin, “Most designers go for larger parts; I think more along the lines of parallel processing (which, of course, is now all the rage in DACs and computing).” The Phi 200 in Mono mode is very much like his design for a stand-alone mono amp, and benefits from the design of the Phi 300 which was a Stereo/Mono design.
 
VAC Fact: Kevin shares, “If there is one thing I have learned in twenty-plus years in audio design, it is not to prejudge things….. I never assume that a particular tube type, capacitor, circuit topology, etc. must be the best. I do not let my theories tell me about the real world; I try to let the real world correct and refine my theories. To that end, we conduct frequent R&D projects that run contrary to our assumptions. In this way, we learn, grow and produce much better instruments than we could have imagined.” A sign in VAC’s listening room reads: In theory, there is no difference between theory and practice. But, in practice, there is.
 
VAC Fact: The cost is similar to acquire one Phi 300.1a or two Phi 200. Which would yield superior results? According to the designer, “I think the pair of Phi 200 would have a slight edge with regard to detail, extension and dynamics. Ah, but then there are the Mono 300’s…”
 
VAC Fact: The three transformers of the Phi 200 weigh more than half of the amp’s total weight.
 
VAC Fact: The Phi 200, like all VAC products, is designed such that you can leave it to your grandchildren in your will. It is crafted to last. The anticipated first major service is the refreshment of the power supply capacitors – after approximately 40-50 years!
 
VAC Fact: There are eleven sets of speakers currently being used at VAC for the voicing process: five sets of dynamic, three sets of full-range electrostatic, one set of hybrid electrostatic, and two sets of horn speakers! The amp was not designed solely to drive the King ESL, but the King was used in the voicing of the Phi 200. Improvements to a VAC design are only accepted if it sounds better with some or all speakers tested and worse with none.
 
VAC Fact: The voicing process may take Kevin and VAC engineers up to 1,000 person-hours in some cases; that’s beyond the time taken to get the amps to measure well on the bench! If Kevin does not approve the sound of an individual component (he listens to each one), it does not ship. Production of certain models has ceased at times for up to two months while tracking down a variance in vendor’s products, such as wires or capacitors.
 
VAC Fact: The voicing process of the Phi 200 was thought to be done until a pair of Zingali horn speakers were hooked up. Through the Zingali, the circuit sounded bright, yet soft, which called for an adjustment to increase the control and precision of the top octave. The cure was affected, but the change was completely inaudible on a pair of Thiel speakers.
 
VAC Fact: Kevin’s opinion of Class D amplification, “… we have neither seen nor heard anything in theory or in practice to suggest that Class D would be a good idea with regard to sound quality.”
 
VAC Fact: At the upcoming 2011 Consumer Electronics Show (CES) in Las Vegas, VAC will introduce the Phi 200i, an integrated amplifier mechanically like the Phi 300.1a, but with 110 wpc. It is designed to overcome many of the shortcomings of integrated amps. It uses two separate power transformers, one for the pre and the other for the power amplifier. It will include a genuine line stage as opposed to being an amp with a volume control, and phono stage. Kevin says, “It should be roughly equivalent to the combination of Renaissance MkIII Preamplifier and Phi 200 Amplifier.” Also on the horizon is the Sigma 160i integrated amplifier (see, another Greek letter name) which will look similar to the Phi 200 and cost approximately $9,900 (NZ$15,495 incl GST).
 
Get a listening VACcination
Got the jitters, a bad case of Audiophilia Nervosa? Can’t seem to find that perfect sound? Nothing seems real enough sounding to you? Doctor Doug says get a shot of VAC equipment and you’ll start feeling better. I certainly feel better every time I use VAC gear in the systems I build. I do mean every time. If there has been one amplifier which has never failed me when reaching for top shelf sound, it is the Phi 200.
 
I already stated in the Signature Preamplifier MkII review that the preamp saves other brands of amps from poor performance; it literally preserves them from ignominy. I can say the same of the Phi 200. Of all the amplifiers my hands have touched thus far reviewing – you can check the list of my reviews – the Phi 200 is the amplifier I would keep. Following are the reasons, based on my listening impressions.
 
VAC equipment has an uncharacteristically big, beautiful sound. I first heard the Phi 200 with the King ESL. Am I glad I did, because there is a possibility that under show conditions hearing it with a different amp I may have dismissed it – a huge mistake. The King is extraordinarily good, and has sounded better with the Phi 200 than with any other amps I have used. I have used some good solid-state and hybrid amps with the king – Cambridge Audio Azur 840W amps in Bi-amp configuration, Pathos Classic One MkIII hybrids in Mono mode at 270wpc into 4 Ohms, a pair of Moscode 402Au, and the Einstein “The Light In The Dark”, as well as some others currently under review. I have had the Phi 200 on loan long enough to have compared it in more head-to-head listening tests with other amps than any other amp I have reviewed. I have heard the Phi 200 on about as many speaker systems as Kevin has for voicing. The conclusion is clear: the balance of power, fullness, and correctness is unparalleled. The King sounds good with one Phi 200, but is inspirational with two of them in Mono mode.
 
Recently a local dealer for VAC instruments came to my home twice to hear the King. The first time he heard it with solid-state amplification and thought it was nice. Prior to his return I told him, “Just wait until you hear the King with two Phi 200’s!” This time he brought his own discs, and this time he left with the phone number of Roger DuNaier at Performance Devices, because he had made up his mind he needed to carry the King as his ESL. It speaks well of an amp when a dealer is swayed to carry a line of speakers from hearing a system which has only had it inserted! The Phi 200 is that good. I know any time I am not hearing sound which is up to my ever escalating standards I can put the Phi 200’s in the rig and get that which I seek.
 
Rodrigo Y Gabriela
If you haven’t had opportunity to look up an incendiary guitar duo named Rodrigo Y Gabriela, I encourage you to do so. This fast paced, punch-packing acoustic guitar pairing has become a favorite for listening as well as conducting demos of equipment. I highly recommend their Live in Japan disc.
 
One track, named “FOC” – I’m almost afraid to know the meaning – has an extended percussion segment with the bodies of the guitars used to thump and pound out the driving rhythm. The clarity and depth of the Phi 200 is exemplary, allowing one to hear much further into the acoustic space of the venue than with the aforementioned amps. The Phi 200 seems to harbor more power than its specified rating. When the guitar is slapped one hears what I heard in the live performance, a powerful wallop, a percussive slam from the close microphone positioning, and a highly amplified signal all reverberating off the auditorium’s wall.
 
One does not hear from the VAC what most amps do to Rodrigo’s picking and plucking, a thinning out of the wiry notes. While initially such thinness is quite noticeable and seems captivating as “detail”, after a short while it becomes irritatingly brittle sounding. At first blush the VAC components may seem laid back, too reticent. But when listening to such intense playing and at higher levels for several minutes, much less a half hour, that more controlled expression of the string’s snap is very welcome as fatigue does not set in. In fact, fatigue never set in with these amps.
 
It reminds me of the lack of strain on the eye looking at a sunset versus summer midday sunlight. The sheer brightness of the sun causes one to squint, to filter out some photons crashing into the iris, but the late afternoon sky is much more forgiving. In the same way, some amps hand the music to your ear “bright and white”, strong and clear but in such a churlish manner that the ear wants to “squint”. Not so with the VAC, as you can put on truly harsh tunes and have the ear wrenching audacity of it ameliorated.
 
I have a couple of nastier test pieces for systems, ones which most systems even at shows fail miserably. One is Lenny Kravitz’s “American Woman”, and another is Apocalyptica’s “Enter the Sandman”. Kravitz plays with the vocals toward the end of the song, distorting his voice out of all proportion to decency. Even on good rigs he sounds so awful that I can usually not listen to the end; he comes across as a robot with a bullhorn singing. As for Apocalyptica, a truly hard driving band with three classically trained cellists and a drummer, I have not much good to say for the music; I just like getting a kick out of seeing if a system can handle it. The strings screech wretchedly, just the kind of effect needed to test the limits of a stereo’s top-end performance!
 
Watch out if you tee up either one of these to hit, because your system is likely to slice and send them sailing “out of bounds”. Only a handful of times have I avoided the cringe-factor when hearing these pieces and one of the only systems to handle them with any kind of aplomb was in my room with the Phi 200. The mollifying effect of the Phi 200 is to make these abominations sound like music. I can actually listen through to the end and pretend like I appreciate it. Anything less than fantastic amplification and these pieces get an automatic penalty; stop the music and move to the next artist.
 
Once I have the Signature Preamplifier MkII and Phi 200 dialed-in, I do not recall any piece I have terminated due to over-aggressiveness. On the other hand, I do recall replaying favorite pieces successively in an attempt to instill more of the mood, the aura, the loveliness of it. I usually want to move ahead, go on to the next experience, but I may repeat a performance when the Phi 200 is in the rig and feel it’s no waste of time.
 
More Stringent Criteria
Increasingly, as I age I am not interested in brightness, or “definition at all costs”. When I was younger I was willing to put up with such antics, but no longer. I have not capitulated on the demand for detail and definition. On the contrary, I demand them more than ever, but with the condition that they must be musically appropriate to the genre and recording. There are only two situations in use of power amps where I can say that both of these demands have been met to my satisfaction. One is with a trio of Coda CS amplifiers (under review) operating the Legacy Audio Whisper DSW in fully active crossover mode, a setup which gives a very unfair advantage to a solid-state amp.
 
The other is the more traditional loudspeaker of either the King Sound King or the Whisper DSW operating in passive crossover mode, powered by the pair of Phi 200 amps. That this setup can compete with a six-channel fully active crossover system is a testament to the authority and quality of the Phi 200. The best part is that the authority and quality is transferrable to any dynamic, full-range ESL or horn speaker system.
 
No kidding around
If you like upbeat vocals, you might want to check out Bobby McFerrin’s VOCAbuLarieS, in which he employs more than fifty singers weaving them into his energized African-inspired choral and solo works. The first track, “Baby”, is infectiously repetitive and upbeat as it brings to mind the runabout antics of a small child.
 
In comparison with the Einstein “The Light In The Dark”, the closest amp in quality to the VAC of those I have used, I found the Phi 200 to offer more heft in the bass singers’ voices, a touch more smoothness in blending all the singers and comparable clarity. When using the Ayon CD-5 as source with its internal preamplifier’s selectable gain setting at MID (6V), vocals sounded as if emanating from oversized heads. This effect was compounded when hearing it through the King, as ESLs tend to expand the center image anyway. With use of the 1-2 Ohm posts on the King and the GAIN of the CD-5 set to LOW (4V), the singers became more life sized and properly weighted. There is a terrific amount of flexibility offered by pairing higher-output sources like the CD-5 with the Phi 200, but you will want to watch out using output over 4V as it will likely begin to “inflate” the amp’s performance. Some people may adore that big-as-the-room sound, but others will want to rein it in.
 
The VAC sound is audio-writ large but properly proportioned; it is elegant, opulent and ebullient. The vastness and spatiality of the soundstage with the Phi 200 is quite surprising when heard for the first time. You may have heard many amps with differing power resources, and different levels of clarity. If you have worked primarily with solid-state amps, you likely have not heard the expansiveness a fine tube amp can bring to a system.
 
Perfect Storm System
The Phi 200 is a natural winner when it comes to symphonic and chamber music. The flush tonal quality of natural instruments created by the Phi 200 enlivens a score. I recently picked up James Horner’s soundtrack for The Perfect Storm, a Deadliest Catch-like account of the Andrea Gail, a long line fishing vessel doomed at sea in one of the worst meteorological disasters to hit the eastern seaboard in a century. As an aside I recommend not only the movie but also the book; so much more of the human element comes through in the painstaking recounting, including a morbid description of what likely the men onboard were undergoing as their ship foundered, sank, and they drowned. The grandeur and gruesomeness of commercial fishing off the Grand Banks is compelling to the spirit of those who labor with their hands as well as those who cheer people finding themselves on the short side of the odds.
 
I like to see what an amp can do with powerfully orchestrated pieces. In The Perfect Storm soundtrack, the periodic wave action flow to the music captures the vicissitudes of the sea. The Phi 200 does not drain the life from the piece, as some amps do. It is easy to be at sea, visualizing the images from the movie; with the VAC I’m not distracted by a question of how that particular horn sounds or why a drum does not seem deep enough. All is rendered with tonal correctness and proper weighting, so I can relax and immerse myself in the moment.
 
Especially rewarding are the tracks “The Decision To Turn Around” and “Rogue Wave”, both of which have attacks of low register horns and tympani. The Phi 200 is exemplary in capturing the surge of the symphony as it crashes in crescendo, emulating the killer waves of the ferocious hurricane. In “Rogue Wave” the last, sustained trumpet blasts speak of panic, heroism – anything that grasps at another moment of hope. The swirling strings and building wall of drums tear at the heart as one conceives the wall of watery grave about to engulf the hapless crew. Following the pounding of the vessel and its sinking an eerie silence ensues, and inevitably the ebb and flow of the ocean’s sub-surface melody is enjoined once again. The humans were no match and will not be remembered by the sea, but washed from memory. The Phi 200 captures the terrific undertow of the score, pulling the ear downward toward the depths in an overwhelmingly compelling fashion.
 
Ideal for any speaker
My experience with the Phi 200 is that I can be assured that no matter which loudspeaker I put into the rig I’ll get top quality sound. About two months ago another manufacturer was visiting for a couple days in order to establish a speaker for review. The VAC components were in use, so it was not surprising to me that I found out later he had enthused to a cable manufacturer that my rig was special. I hadn’t even gotten a chance to work with the speaker for weeks to dial it in. Already with the “first run” the system was charming; the VAC gear was working its magic.
 
I find it difficult to determine which system I prefer, the big panels or the big dynamic hybrids. The Phi 200 in mono drives them both with authority and acuity. With most amps I have to work hard to get a sustainable level of palpability, of convincingly true-to-life sound. Not with the Phi 200. In a matter of one evening I can dial it in to find a viscerally moving experience.
 
Here is a secret about how I build high-end systems. I do not spend weeks or months sitting around pondering their sound. If something does not sound right I act directly and immediately to make the effected repair. Consider that industry leaders head to a show and set up in a room from scratch. They do not have weeks or months to futz with sound. They must get it right as best they can, many times literally overnight. Some are definitely better than others, but most do a commendable job given the schedule and circumstances.
 
I have found that it’s counter-productive to waste weeks and months seeking an optimum sound when the ear senses an obvious defect. If a system doesn’t sound good to me I do not wait on it, I change something! For this reason I keep two or three types of cables on hand in order to tune rigs. There are tens of thousands of permutations available for systems. Why should I waste weeks or months of my life with a so-so sound when I can potentially improve it immediately? The longer I have been in the game the less patience I have to adopt a “wait-and-see” attitude. I have a firm grasp of my electronics collection and media collection, as well as how I demand it to sound. If it’s not where I want it to be, I’m not about to spend weeks suffering its insufficiency. Something’s getting reworked! Of course, finances can slow down the process, but if finances are not hindering and the rig doesn’t sound right, it’s not going to stay that way for long.
 
Imagine the number of audiophiles who sit in discontent at their rig’s sound, pining for improvement! How many hope that it will improve on its own with weeks or even months? If you don’t want to spend the majority of your time as a discontented audiophile, get to work! I spent far too many years hoping for incremental improvements, so I want to encourage those who are frustrated not to accept waiting and doing nothing. If there is an annoying aspect to the system, change a power cord or two, or try a different speaker placement, or put a pillow behind the speaker to test if room treatments might help. Your ears will tell you if you are going in the right direction, just as your eyes tell you when you see a beautiful person. Influence change for improvement rather than be a victim of inaction.
 
However, once a very pleasing sound has been found I slow the process down every bit as dramatically. The ear will tell you when it hears something good. When my ear sends the signal, “Ah! I really like this sound,” I halt the system reconfigurations and spend time enjoying. More often than not the system will remain fixed for some time and I will authentically thrill to the sound of it for weeks. It’s so much better than leaving niggling concerns about the sound unaddressed. If I get my concerns about the sound dealt with up front, I find myself much more content with the system for longer periods of time such that I become reluctant to disassemble the rig!
 
When I’m in “Reconfiguration Mode”, usually cables are the first to be reworked, partly because they can be incrementally changed, and partly because they are easiest to work with physically. If I’m confident of the source’s quality then the next thing to be considered for change is the amp. But never the VAC Phi 200. I have moved it in and out of the rigs I have built enough times that I have heard the devastation resulting from its removal. It has become an “anchor component” which has proven itself the best option no matter which team of components I assemble. Inevitably, it is re-inserted into the system to restore much needed vitality. When another amp’s review work has been concluded, out it goes and in goes the Phi 200. I have preferred over the months to build rigs around it rather than work without it. This confirms Kevin’s voicing process, whereby the amp is conditioned to be compatible with a wide range of speakers.
 
Thus it was that recently when I put the Whisper DSW back into the rig I instinctively reached for the Phi 200’s, no matter the other components and cables. I keep an updated exact system list from power cord for the source to speakers for the “Best Rig” with every speaker system. I could have simply recreated my previous best rig. However, I decided to fly solo and rework the cabling again. In the span of two hours and four partial cable changes, I was content. The results obtained are often so right, so spot-on that I leave it that way for weeks until another review priority forces change. As amps have come and gone, the Phi 200 has remained and if I had the means financially they would remain permanently. Their quality, reliability and unimpeachable sound earn them a resounding recommendation.
 
In conclusion I leave you with two more VAC Facts.
Firstly, Kevin is also interested in the quality of the discovery and reporting in regards to his products as they are used in real-life systems. He is not so concerned with analyzing specifications to death, but rather what works in terms of obtaining the best sound. This review is my most comprehensive to date in terms of an amplifier’s use with other components. I subjected the Phi 200 to more sources, preamps, cables and speakers – systems – than any previously reviewed piece. It yielded top-quality sound with a large body of available components.
 
Secondly, with CES around the corner and enthusiasts hearing his components, I suspect Kevin is about to get a lot busier. If you like what you hear and seek a VAC instrument, be patient. Your patience will be well rewarded. Kevin’s concern is producing a quality instrument above all. You are paying him for the best amp he can build, and he’s going to make sure you get it. That is why he’s going to listen to it before it ships.
 
Manufacturer’s comment:
Thank you for the thorough and thoughtful review of the VAC Phi 200, as well as for the courtesy and professionalism always shown us by everyone at Dagogo.
 
A quick note about the VAC / KingSound demonstration at the inaugural 2010 California Audio Show. After discussions with the dealer, Bob Kehn of Audio Image, who presented the room, it was determined that the King’s panels likely were not fully charged most or all of the time, which results in reduced sensitivity and premature clipping of the panels themselves. The problem was that the speakers were left unplugged when the alternate Magico speakers were being demonstrated. Normally I would not have thought of this, but we experienced a similar issue during setup at Axpona; the speakers had to be plugged in (and unplayed) for several hours before they would play normally. Clarity about this is important, as we would not want the King’s to get a reputation for being difficult to drive, nor would we want the stereo Phi 200 to be viewed as marginal for the task!
 
To clarify the bias setting of the output tubes, the proper procedure is performed without music playing, as initially stated in the review. Once the proper settings have been achieved, in normal operation one will notice that the LEDs will be dark when no music is playing, and will light ‘with the beat’ as music is played. However, this is not part of the adjustment procedure, and there is no need to select a particular kind of music, etc.
 
Thank you again for taking the time to review the VAC Phi 200. We count it a privilege.
 
Kind regards,
 
Kevin Hayes / VAC
 
The Signature proved to be one of my "audio epiphanies"—a point where my system moved to a new plane that redefined the intensity of my connection to the music
Brian Damkroger

With the "right supporting cast," the VAC Renaissance Signature Mk.II is the best preamp I've auditioned. Its resolution of low-level spatial, temporal, and timbral detail, and its uncanny coherence across the realms of space, frequency, and loudness, put it in a class by itself. These strengths made listening to a musical performance through the Signature a more moving experience for me, and one step closer to the real thing.

I had a wonderful audio moment the other night. It was late in the evening, after a long day. I was standing in the middle of my makeshift listening room—Trish's dining room—and in spite of the fact that we were moving in just a few weeks, I'd just unpacked and set up my combo of VPI TNT Mk.V-HR turntable and tonearm with Grado Statement cartridge and dug a box of LPs out of the stacks in the garage. I cued up Dave Brubeck's Time Out (Columbia/Classic CS 8192), and the first notes of "Blue Rondo à la Turk" froze me in my tracks.
 
The music hadn't just started, it had come to life. I sat down, mesmerized, and the stress and pressures of the day melted away, replaced with feelings and emotions from other times and places. There was a tinge of the electric excitement that permeates the air before a concert, when the lights dim and the performers take the stage. There was also the simple joy of being swept away by music. But most of what I was feeling, I think, was a lightness and happiness that reminded me of discovering music and audio in college and grad school, a joy that, in the recent frantic weeks and months of swirling logistics, merging families, moving, and endless business travel, had somehow gotten lost.
 
Aromatherapy is based on the premise that a profound, direct connection exists between the olfactory receptors and the brain—how the smell of new-mown grass, for example, can make us feel the way we did as a child. I occasionally experience the same sort of thing based on my hearing. Sounds—often music, but not always—can take me back to other times and places. Not just remind me of them, but actually re-create the feelings I had. As I've traveled through the world of high-end audio, I've often found that inserting into my system a new, profoundly better component, one that raises the system's performance to a higher plateau, can re-establish this connection, or make it noticeably more direct. In this case, the source was easily identified: the Valve Amplification Company's Renaissance Signature Mk.II preamplifier.
 
A Renaissance preamp at last! 
The Renaissance Signature was released in 2000 after six years of development by designer Kevin Hayes. At $17,000 ($13,000 without phono stage), it was VAC's top model, and the first VAC preamp to bear the "Renaissance" name. Now, the Signature has been extensively updated and become the "Mk.II." The most notable changes between the original Signature and the Mk.II are the use of both input and output coupling transformers in the line stage, and the deletion of the pair of 12AX7 tubes from the line stage, leaving only a pair of 8417 dual-triodes as a differential gain stage, and a pair of 12AU7s as the buffer circuit for the tape output.
 
The bulk of the design elements that made the original Signature so special remain in place. There are no coupling capacitors in the signal path and no loop negative feedback. The gain stage is fully differential, and consists of direct-heated triodes. On the input side, the Input Selector switch both selects the source and sets the grounding for balanced or unbalanced sources, the latter converted to a differential configuration at the input transformer.
 
Both balanced (XLR) and unbalanced (RCA) outputs are provided, with a rear-panel selector switch selecting between the two and, again, establishing the appropriate grounding configuration. The output transformer not only converts the differential signal to unbalanced if necessary, but also allows the Signature Mk.II to drive virtually any combination of cable and amplifier inputs. In fact, the VAC's current capabilities are said to rival those of many small class-A1 power amplifiers.
 
The VAC's phono stage is an unusual configuration, and struck me as a throwback to an earlier time. Through the MM (moving-magnet) inputs, it provides 44dB of gain via a single, fully differential gain stage, implemented via six 12AX7 dual-triode tubes. Through the MC (moving-coil) inputs—and when that rear-panel switch is flipped—rather than increase the gain actively, the switch inserts a pair of wide-bandwidth transformers into the circuit to achieve an additional 20dB of gain. In either case, it uses passive equalization. I did the bulk of my listening using either a Grado Statement or a Benz Micro L04 cartridge, and the MC inputs provided the best mix of detail, depth, texture, and dynamics.
 
The Signature looks gorgeous. Its faceplate is a thick, softly sculpted slab of aluminum finished in a flawless, glossy black embedded with gold flecks that beautifully complement the heavy, gold-plated knobs. There are large knobs for Input Selection and Volume, flanked by two smaller ones on each end: Mute and On/Off on the right, Tape Monitor and Cinema/Direct on the left. The Cinema input provides a fixed-gain path from input to output, allowing a user to send the front channels of a home theater or surround system through the main audio circuit, but controlling the level with a processor or A/V preamp.
The Signature's lower chassis, which houses completely separate power supplies for the line and phono stages, mirrors the main unit's shape, size, and cosmetics. Its front panel houses two large, gold-rimmed, backlit meters, which monitor the heater and main, B+, voltages. No scales or numbers are provided, but a dot at the center of the meter's range indicates the proper operating voltage. Both chassis have nifty backlit VAC logos that glow red when the unit is muted, blue during operation.
 
Listening: Do you believe in magic? 
I've already tipped my hand that, when everything clicks, the VAC Renaissance Signature was capable of truly magical performance. But what exactly was it about this preamp that made it so captivating, and how did it measure up in all of the areas we audiophiles hold dear?
 
The single most impressive thing about the VAC, and the area where it stood head and shoulders above any other preamp I'd heard, was its resolution. At low levels, whether a single plaintive note fading ephemerally into the surrounding ambience or a subtle countermelody buried deep in the orchestration, the Signature retrieved more tonal, spatial, and temporal information than any other unit I've heard. With the VAC, there was never any question that an orchestral section was composed of multiple instruments, each in a distinct position and each with a characteristic tone, texture, and presence. A lot of top-quality gear reveals this level of detail in the major components of the orchestration, or in the front half of the stage, but where the VAC really stood out was in how well, at lower levels, it reproduced details of instruments buried way down in the mix or at the rear of the stage.
 
On record after record, subtle countermelodies I'd not even been aware of emerged distinct, detailed, and articulate. The very soft trumpet passages about two-thirds of the way through Saint-Saëns' Bacchanale, from the Paris Conservatoire Orchestra's Ballet Music from the Opera, Anatole Fistoulari conducting (LP, RCA/Classic LSC-2400), were good examples. I might have been dimly aware of their presence before, but with the VAC, the trumpets were distinct, detailed, and tangible instruments, each one richly portrayed and contributing its subtle tonal shadings and phrasings to the multiple countermelodies.
 
Another example was the soft oboe line shadowing Artur Rubinstein's solo piano through the early portions of his performance of Brahms' Piano Concerto 1, with Fritz Reiner conducting the Chicago Symphony (LP, RCA/Classic LSC-1831). As in the trumpet passages in the Bacchanale, the oboe was not only obvious, but lovingly portrayed, with complex, woody tonal colors and a level of detail that made me think I could hear every expression, every nuance of phrasing and dynamic shading.
 
The VAC's re-creation of nuance was equally as good—if perhaps not unique—on more prominent components of the orchestration, adding dimensionality to Rubinstein's piano on the Brahms, for example, and additional layers of subtlety to his playing. One thing that stood out was that, with the VAC, the cushion of air surrounding the piano was distinct from and clearly outlined the instrument, rather than the two merging into a single, diffuse image. The effect was to add dimensionality and solidity to the piano, and additional life and realism to the performance.
 
The VAC's resolution was similarly excellent, though not unusually so, at the loud end of the spectrum. Full-bore orchestral crescendos were appropriately enveloping and overwhelming in their weight and power, without ever losing focus or becoming confused. Midway through the first movement of the Reiner/Chicago reading of Bartók's Concerto for Orchestra (LP, RCA/Classic LSC-1934) the trumpets explode in full-tilt crescendos. Through it all, they retained their unique identities and brassy bite without ever getting overbearing, hard, or edgy. Massed violin crescendos, no matter how intense, remained a coherent group of individual instruments, never becoming hard or steely.
 
The reproduction of dynamic contrasts, like the resolution of detail and tonal nuance, was another area where the VAC's performance was truly special. Most good components reproduce dynamic contrasts evenly and well across the middle range of frequency and loudness. The VAC extended that range from the upper bass to the lower treble, and from the softest pppp whispers to the loudest ffff crescendos. Those subtle, nearly buried countermelodies weren't just wonderfully detailed; their microdynamic shadings were beautifully articulated as well. Every nuance was clear, and seemed much more obvious and dramatic than with other preamps.
 
This combination of superb low-level dynamics and incredible resolution of detail resulted in jaw-dropping re-creations of original ambient environments. Halls—their sound, their boundaries, their space—were stunningly portrayed, and much more integrated with the instruments and their surrounding spaces than I'd ever heard before. Once I'd heard the VAC, it became apparent that, typically, only the grossest of ambient cues are reproduced, which leaves things a bit disjointed and incoherent as the level drops. With the VAC, the coherence—the weaving together of the instruments, surrounding air, and the hall itself—was much more complete and much more realistic.
 
Midway through the Saint-Saëns Bacchanale is a delicate exchange between the woodwinds and French horn. With the VAC, it wasn't simply point/counterpoint, but more like a tennis match, the lines bouncing back and forth between the instruments, their location and interaction with the surrounding space and hall boundaries transcribing an arc through the air above the orchestra. This particular passage was especially captivating because the span so beautifully described was truly three-dimensional, traveling not only laterally but also front to back and vertically, describing the relative heights of the instruments as well as their positions on the stage.
The VAC did an excellent job of soundstage reproduction as well, though no better than most top-quality preamps I've used. Similarly, the VAC was tonally neutral from the upper bass through the lower treble, but not uniquely so. In fact, I've heard gear—the Audio Research Reference 2 preamp and the Sonic Frontiers Power Three amps, for examples—that sounded more neutral than the VAC. In comparison, the VAC sounded slightly soft at the frequency extremes. This was partially due to slightly attenuated dynamic contrasts, which I'll discuss in a bit, but the VAC did sound slightly rolled-off, particularly at the very top. The piccolos in "Dance of the Moorish Slaves," from Verdi's Aida (Ballet Music from the Opera), or the triangles in Bacchanale, were gorgeously detailed and had a beautiful, complex ring, but didn't seem to cut through the air as crisply and cleanly as they should have. Nor did they have the sharp initial transient, or the endless waves of higher and higher overtones emanating outward from their center.
 
On the bottom end, the VAC's extension was good, with sufficient weight, and double basses, timpani, and bass drums were rich in tonal color and beautifully detailed. But the dynamic contrasts just weren't as large or as sharp as they were from the upper bass through the lower treble. For example, the initial transient of a bass drum, the whooompf, didn't start as sharply or traverse as great a dynamic range as it does in real life—or as it does with some other top-drawer preamps.
 
One aspect of the VAC's sound that left me scratching my head was its speed, or lack thereof. On one hand, the Signature handled everything I threw at it with agility and aplomb. "Dance of the Moorish Slaves" is a raucous cacophony of sounds, chock-full of fast transients, and the VAC handled it beautifully. And, as I've mentioned above, the scale of the VAC's dynamic contrasts is at least a match for other preamps, except perhaps at the frequency extremes. On the other hand, the Signature just didn't sound as fast as some other preamps I've heard. It left me wondering whether the VAC was softening transients slightly, perhaps due to its use of transformer coupling—or whether the Signature's additional low-level detail and tonal richness were just contributing a greater continuity, and other components might be leaving things just a touch rough around the edges, and thus sounding faster and more abrupt.
 
One last component of the VAC's sound, and perhaps a reason that some other units can sound more neutral, was its texture. To say that the Signature had a "liquid" texture is too gross. To even compare it to a desert—er, California—afternoon with just a touch of humidity is still overstating it. Think of a cold, crisp mountain dawn. When you've got a handle on that, fast forward to about 11am, when things are just starting to warm up. It's still as crystal-clear as it was at sunup, but everything seems just a bit softer. That's the VAC—just the faintest sort of softening or sweetening.
 
All of the reference recordings cited here are LPs. Although I had excellent CD players to use, I never found a combination of player and cable that matched the performance I got from the VAC with vinyl, or that revealed the Signature's true glories. This isn't a criticism of its line stage, for it was part of the circuit for vinyl playback as well. If anything, it points out how finely tuned a system must be to really appreciate a component like the VAC, and how carefully associated components must be selected. The choice of interconnect between the VAC and my VTL Ichiban power amps, for example, made a night-and-day difference in the system's sound. Neither the AudioQuest Anaconda nor the Nordost Valhalla—both superb cables—worked at all for that connection, the former sounding slightly opaque, the latter quite forward and two-dimensional. It was only when I installed the Nirvana SX-Ltd. interconnects that the VAC truly sang. Kinda scary, but without the right supporting cast, the Signature was "just another great preamp."
 
Conclusions 
With the "right supporting cast," the VAC Renaissance Signature Mk.II is the best preamp I've auditioned. Its resolution of low-level spatial, temporal, and timbral detail, and its uncanny coherence across the realms of space, frequency, and loudness, put it in a class by itself. These strengths made listening to a musical performance through the Signature a more moving experience for me, and one step closer to the real thing.
 
The Signature was not entirely transparent, however. It contributed to the sound a softening and sweetening, however slight, that I heard throughout the frequency spectrum but most clearly at the extremes.
 
The Renaissance Signature is expensive, and mercilessly revealing of shortcomings in surrounding components and cables, almost to the point of undue sensitivity. It must be paired with the very best sources and cables to truly shine, and will be appreciated only if followed by truly superb amplification and speakers. All in all, it's not a prospect for the faint of checkbook.
 
But if the most realistic, most engaging, most mesmerizing re-creation of a musical event is your goal, the VAC Renaissance Signature Mk.II demands an audition. The Signature proved to be one of my "audio epiphanies"—a point where my system moved to a new plane that redefined the intensity of my connection to the music. Unfortunately, such experiences also tend to redefine my expectations of what an audio system—and, ultimately, my checking account—should be able to do. Trish and I are closing on our dream house at the time of writing, and contemplating being house-poor for the next, oh, 20 or 30 years, so this isn't a particularly good time to be contemplating $17,000 preamps.
 
But where there's a will, there's a way, right? Definitely, very highly recommended.
Seek out a demo
Ghasley - Audio forum member
I am the proud owner of a VAC Sigma 160i amp mated to a pair of Wilson Audio Duettes. Not Sofias but very very similar. The 160i is simply stunning. I will try to describe for you. My recent amp journey was a Naim Supernait, then to a VAC Phi 200 driven directly by a Berkeley Alpha DAC, now the Sigma 
The characteristics of the Sigma is going to sound cliche but imagine mating the best characteristics of solid state....crisp snappy bass with the best of tubes, smooth articulate mid range with gorgeous highs. I have about 5-600 hours logged so far and it keeps getting better. This is the amp Kevin Hayes has in his home. The phono stage is terrific.
 
This amp is NOT bloomy at all.....it has prat, snap, excellent bass and it is very romantic sounding without going too far. I have installed NOS Mullard 12ax7's in the phono section and NOS 12au7's in the input stage, all other tubes are stock from VAC. Everyone has different value judgements but I believe this integrated is fabulous and it has ended my search. My setup is presently a REGA P5/Exact2, Playback Designs MPD-3/Mac Mini, Vac Sigma 160i, Wilson Duettes (no sub, doesn't need one in my largish room).
 
Seek out a demo, i believe VAC will be showing the Sigma at RMAF. Every dealer i spoke to about it prior to my purchase was quite effusive about the sound(when are they not!) yet I have to agree. good luck.
I would suggest, without reservation, an audition to anyone looking for a high end integrated to see if you like it as much as I do.
Jgc - audio forum member
I have had my VAC 160 with optional MC Phono and Bal input for about 6 months now. I am thoroughly satisfied with this purchase and enjoy using it every day - no buyers remorse or interest in looking for anything else. I wound up buying a TW Acustic analog setup with Ortofon arm and Dynavector cart from Jeff at Highwater Sounds (who also sells VAC). I have a very nice digital setup with Macbook and ARC DAC8 that I enjoy for many reasons, but I have to say the synergy between the Raven One turntable and VAC MC phono is more compelling to me than any digital I have heard or owned. 
 
Although relatively new to vinyl, I find I listen to it much more often than digital now with this system. I have never heard anything better at this price point and I think that it probably competes well above its class. As I suggested in a similar post on the Best Integrated thread, the simplicity and reduction in the number of boxes and cords is a bonus for me, but the magical sound of this combo is what lures me back to listening more than I have in the past with other systems. 
 
This hobby is very individualistic and we all have different preferences and priorities but I would suggest, without reservation, an audition to anyone looking for a high end integrated to see if you like it as much as I do.
The VAC 160i, simply put, makes beautiful music.
Ikkyu2 - audio forum member
I heard the VAC Sigma 160i at RMAF last weekend. It blew me away. I ran it through all my demo CDs and a few of the LPs they had there. I went back to the room twice. I probably spent at least an hour total listening to this setup (nicely matched with Tannoy Definitive T10 speakers).
 
I have an Art Audio Vinyl reference, Joule Electra LA-150 MkII, and Genesis M60 mono blocks and have been totally delighted with that combination. The 160i has me seriously thinking of going to integrated. 
 
The 160i at RMAF had the MC phono section and I was doubtful that it could be equal to the best separate phono pre. My doubts were dashed. Kevin has designed a tour de force for the vinyl lover. 
 
The amp is detailed but liquid and smooth and the bass is completely authoritative without any bloom.
 
The VAC 160i, simply put, makes beautiful music.
If I could afford the Signature SE, I'd buy it.
Bob Reina

REVIEW SUMMARY: The Valve Amplification Company's Signature SE preamplifier is the most significant audio product I've ever hooked up to my reference system. It was flawless. Overall, based on my aural memory, it exceeded the performance of every other preamp I've heard in my house. And for the first time in more than 25 years of audio reviewing, I was hearing a component that caused me to enjoy my own reference system less when I reinstalled my regular preamplifier. That's one problem I don't face when I review entry-level bookshelf speakers!

If I could afford the Signature SE, I'd buy it. But that would mean convincing my wife to keep working another year before retiring. It would not go over well. Still, the day I removed the Signature SE from my system, to send it on to John Atkinson to be measured, my wife came home from work, looked at the rearranged components on my rack, and said, "What? The preamp's gone?"

EXTENDED REVIEW: For me, the highlights of any audio show are finding a room with great sound and visiting it often throughout the show, to relax and absorb a wide range of great music. At the NY Audio Show in April 2012 in New York City, it was the room occupied by the Valve Amplification Company. There, I fell in love with the sound coming through the Signature Mk IIa line-stage preamplifier, and remembered that while I'd heard many VAC products at audio shows over the past two decades, and had enjoyed the sound every time, I'd never had a VAC product in my house. I requested a review sample.

A saga began. VAC is a small company, but the demand for its products is high, and backorders caused several delays. VAC was understandably reluctant to send a sample to a reviewer and thus make a customer who'd already paid for a unit wait even longer. Then the company's founder, Kevin Hayes, called with some good news. VAC would be introducing an upgraded version of the Signature Mk IIa, the Signature SE, which would include technology trickled down from VAC's flagship preamplifier, the Statement Line ($75,000). If I could wait just a bit longer, I could have an early-production Signature SE.

Well, of course! I requested a sample of the Signature SE ($19,500) that included the optional MC/MM phono stage ($6500): total retail price, $26,000. Some two years after my initial request, a Signature SE finally arrived. I wondered if it would prove worth the wait.

Designing
According to Kevin Hayes, the Signature SE line stage is, in effect, a small, zero-feedback, class-A, triode power amplifier with a step-down output transformer. He claims that this makes its output very stable and nonreactive and, as such, resistant to the stray interactions of the power amplifier and source component that can occur when various types of feedback are employed. The line-stage circuitry is hand-wired from point to point. The Signature SE controls the volume level using high-grade potentiometers; Hayes concluded from his testing that chip controls and stepped attenuators are sonically inferior.

The optional phono stage is no mere afterthought. It uses six 12AX7 triode tubes and, like the line stage, no feedback. It has its own power transformer and filter circuit, and has moving-coil and moving-magnet inputs, each with variable loading. The MC input is routed to a step-up transformer that provides another 18dB of gain before the MM stage. I'm impressed that VAC has figured out a way to incorporate a phono stage with six tubes, two transformers, and additional circuitry within the case of an existing line stage.

The Signature SE also includes the input transformers used in the Statement Line, and several other features not found in the Signature Mk IIa: improved input signal routing, enhancements of and a new layout for the phono circuit, and a new layout for the line stage.

The Signature SE has five line-level inputs, three of which can be configured for balanced or single-ended operation; and two outputs, each configurable as balanced or single-ended. If the preamp is ordered without phono stage, the phono input can serve as a sixth line input. Also featured is a Cinema Bypass input, which has fixed gain, for use with home theater systems, where control of system volume will be handled by the processor.

On the Signature SE's front panel are an input Selector, and controls for Volume, Mute, logo brightness intensity, Power, and Cinema bypass. The rugged but tiny remote control has three buttons: volume up, volume down, and mute. When I handed it to an audiophile friend, he said, "That's all you need."

The Signature SE comes with an outboard power supply. I was amazed that it ran very cool, despite the fact that it has eight tubes and only a few discreet ventilation slots.

I auditioned both the line and phono stages, using into the MC input my Koetsu Urushi cartridge, loaded at 100 ohms.

Listening
I've now auditioned quite a few expensive tubed line stages in my house, and every one has fit this pattern: flawless or nearly flawless sound, each with a unique sonic personality that would match certain listening tastes. But just as none of those preamps fell short of the others in any meaningful way, not one so outperformed the rest that I would prefer to listen to only it.

With the arrival of the VAC Signature SE, that changed. I spent many weeks listening to it, trying to describe how this preamp presented a more realistic reproduction of live music than any other preamp I'd heard in my house, but found it difficult to put into words. True, with every recording I played, the Signature SE gave a flawless performance—I could find nothing even approaching a weakness shortcoming. It produced an illusion of live musicians playing in an actual space better than any preamp I'd heard.

As I dug deeper into my music collection, I concluded that, in three critical areas, the VAC achieved a level of performance I hadn't thought possible from a tubed line stage:

1) Levels of detail resolution, ambience retrieval, air, and low-level dynamic articulation across the audioband that were nearly indistinguishable from a live performance.

It's winter. You're late for work. Your windshield is covered with nearly frozen fog and haze. You can't see. You crank up the heater and defroster, but can't wait for them to do their duty. You grab a damp rag and wipe the inside of the windshield as best you can, applying extra elbow grease to the center on the driver's side, to maximize visibility. You drive off. Your visibility is pretty good at the center, but around the periphery a foggy haze still limits your vision. You should have waited five minutes to fully warm up the car, let the defroster run full blast, then driven off with a crystal-clear windshield and full visibility.

The Signature SE's clarity, transparency, and resolution were analogous to waiting those last five minutes. By comparison, other expensive tubed line stages I've heard sound like the quick rag job. The midrange might be gorgeously transparent, but some other regions of the audioband are less tactile, less lifelike. With the Signature SE, the crystal clarity extended throughout the audioband and all areas of the soundstage with all recordings: In every case, I could hear deeper into the performance.

2) Lightning-fast articulation of transients but with no hint of sharpness, and no sense of dulling or softening at the frequency extremes.

I love percussion recordings and their sense of transient speed. But in the reproduction of a recording, I don't want any trace of sharpness or etch. Neither do I want the softened transients at the extremes of the audioband that I've heard some line stages produce in an attempt to avoid an "etched" sound. The Signature SE never approached either quality with any recording. All percussion sounded extremely fast and lifelike, with no artificial edge, nor was there ever the slightest hint of softening in any frequency region. Not surprisingly, the VAC was also unforgiving of any recording whose sound included even a bit of transient edge; there was no tube-like softening.

3) Detailed, revealing, extended, uncoloured reproduction of high frequencies with no loss of delicacy.

The Signature SE was the holy grail of high-frequency reproduction. Every region of the highs was detailed, undistorted, uncolored, and delicate. Normally, when I play a recording through a component with good HF reproduction, at some point, the music hits a frequency where the highs lose some of their delicacy or airiness, or take on a subtle brittleness. Not with the VAC. From the lower highs through the top of the audioband, the highs were detailed, extended, and "right," every bit of delicacy and air intact. I'm not used to hearing this type of realistic reproduction from an audio component. I'm used to hearing it from a violinist sitting 10' away.

Sounding
One recording I like to use to test the reproduction of transients is "This Way Out," from John Zorn's Music for Children (CD, Tzadik TZ 7321). This brief, high-tempo jazz-rock piece changes genre every few seconds, much like Carl Stallings's scores for the classic Warner Bros. cartoons, and there are plenty of opportunities for audio components to smear these crazy transients. The VAC didn't. Transitions from one breakneck passage to the next passed with the precision of a samurai's sword. I enjoyed even more the title track, a chamber work. The piano part is written with a lot of space, and pianist Julie Steinberg spends time covering the entire range of her instrument. In a couple of segments she plays very dynamically at the extremes of her instrument; with the Signature SE, I was struck by how the dynamic attack, the timbral envelope, and the decays of the notes sounded more like a real grand piano than I'd ever heard with this recording.

George Crumb's Music for a Summer Evening (Makrokosmos III), scored for two amplified pianos and two percussionists, is my favorite chamber recording (LP, Nonesuch H-71311; CD, Nonesuch 79149). I've played it more than a hundred times, and have never gotten tired of it or the stunning recording quality, which is very revealing of audio components. I listened to the last two movements through the VAC and was transfixed by how the preamp revealed clearly different dynamic envelopes for each of the percussive passages. Instruments with significant top-octave energy—mallet percussion, bowed cymbals, bell tree, the pianos—shimmered, every subtle detailed revealed without smearing. The decay of all notes, and the way the VAC picked up the sound of the recording venue, were stunning. The emotive crescendos of the final movement so reminded me of the live performance of this work by the same musicians of the Contemporary Chamber Ensemble, at New York's Symphony Space in 1979, that by the end of the movement I was in tears.

You always remember your first Shaded Dog. In the early 1960s, my father opened his first business, an appliance store, and RCA was one of the brands he carried. RCA sent him many copies of their Living Stereo classical recordings, to show off the newly arrived RCA "combinations": TV, radio, and stereo phonograph, all in one beautiful console! My father brought many of them home for me. At an early age, I was smitten by Jascha Heifetz's recording of the Sibelius Violin Concerto, with Walter Hendl conducting the Chicago Symphony Orchestra (LP, RCA Living Stereo LSC-2435, footnote 1). I love Heifetz's aggressively virtuosic interpretation of the opening melodic statements, which give his violin a workout throughout its range. I've never heard a recorded violin sound more natural through my system than Heifetz's did through the Signature SE. The bite, the rosin on the bow, the shimmering air of Chicago's Symphony Hall—all were clearly delineated.

In fact, I found the Signature SE an ideal match for well-recorded orchestral music. With such complex works as Bartók's Concerto for Orchestra, with Fritz Reiner leading the CSO (LP, RCA Living Stereo LSC-1944), it was easy to follow each line in the work's densest passages. Piano concertos, too, were engaging—with Earl Wild's recording of Gershwin's Rhapsody in Blue with Arthur Fiedler and the Boston Pops (LP, RCA Living Stereo LSC-2367), and Byron Janis's of Rachmaninoff's Piano Concerto 3, with Antal Doráti conducing the London Symphony (LP, Mercury Living Presence SR 90283), it was very easy to analyze each pianist's unique phrasing as the piano floated on its own bed of air, with no interference from the sound of the orchestra. String concertos, too, impressed. When I listened to János Starker's recording of the Dvorák Cello Concerto with Doráti/LSO (LP, Mercury Living Presence SR-90303), his cello was a holographic, vibrating, organic entity. Finally, the Signature SE's great sense of rhythmic pacing gave sprightly upbeat works, such as Malcolm Arnold's English, Scottish & Cornish Dances, with the composer conducting the London Philharmonic (LP, Lyrita SRCS 109), a lively, engaging feel.

The VAC was also impressive with vocal works. In three excerpts from Berg's Wozzeck, again with Doráti, Helga Pilarczyk's soprano floated on a bed of air over the LSO, and it was easy to follow each line in the orchestral accompaniment (LP, Mercury Living Presence SR 90278). And with Elgar's Coronation Ode—with Philip Ledger, the Cambridge University Music Society Chorus of King's College Cambridge, the New Philharmonia Orchestra, and the Band of the Royal Military School of Music, Kneller Hall (LP, EMI ASD 3345)—it was very easy to follow individual choral lines.

I also enjoyed pop vocal recordings with the Signature SE preamplifier. On Richard Buckner's Bloomed (CD, Merge 50355), his voice was rich and supple over the backdrop of his pristine, shimmering flattop acoustic guitar. And it was very easy to analyze Lucinda Williams's unique phrasing in "Right in Time," from her Car Wheels on a Gravel Road (CD, Mercury 314 558 338-2). I dug out Dusty Springfield's performance of "The Look of Love," from the Casino Royale soundtrack (LP, Colgems COSO-5005). As I'd expected, Springfield's voice was rich, sulky, and supple, but the engineering turned me off a bit. It was so obvious through the VAC that she'd been recorded in an isolation booth that she seemed detached from the instruments; it took away from the realism of the performance.

To test the Signature SE's bass performance, I fired up "Aurora," from Jon Hassell's Last Night the Moon Came Dropping Its Clothes in the Street (CD, ECM 2077). The opening bass riff shook the room with no trace of overhang, coloration, or compression. The VAC was also adept at delineating differences in sound quality among recordings, as well as letting me analyze the engineering of individual mixes. One of the two "Records to Die For" I wrote about in the February 2015 issue was Acoustic Sounds' remastering of Reiner/CSO's recording of Mussorgsky-Ravel's Pictures at an Exhibitio, (LP, RCA Living Stereo LSC-2201)—but that was before I played it through the Signature SE. The VAC revealed this recording to have even wider dynamic contrasts than I'd thought. Moreover, the violin string tone was the most natural I'd heard from any reissue of an RCA Living Stereo recording.

In one of my listening sessions with Chris Jones, the composer and bassist for my jazz quartet, Attention Screen, we listened to a 16-bit/44.1kHz CD burn of the master file of his latest solo fusion release. Chris had never heard his music through so revealing a system. He found it ridiculously easy to analyze each recording technique he'd used in these tracks, and every special effect he'd devised to achieve a bit of drama. Chris was amazed at how the VAC revealed the brand and model of recording and processing gear he'd used for each section.

Comparing
I had on hand no preamps in the Signature SE's price range for a direct comparison, but I did have my reference Audio Valve Eklipse line stage ($5799), as well as the Audio Research SP20 preamp ($9000) The Audio Valve was just as delicate and as involving as the VAC, but it revealed less decay and ambience, transients weren't as crisp, and highs weren't as pure or as intimate. Although the Eklipse's bass performance was superb, I felt the Signature SE went slightly deeper. Also, the midrange through the Audio Valve was more forward; the VAC produced more of a mid-hall perspective.

The Audio Research SP20's midbass wasn't as tight as the VAC's, but the ARC's resolution of low-level detail, especially in the midrange, was closer to the Signature SE's than to the Eklipse's. The SP20's highs were extended, but not as pure as the VAC's. The ARC's low-level dynamic capabilities were excellent—very close to the VAC's—but the latter's high-level dynamics were superior, especially in the mid- and lower bass.

Concluding
The Valve Amplification Company's Signature SE preamplifier is the most significant audio product I've ever hooked up to my reference system. It was flawless. Overall, based on my aural memory, it exceeded the performance of every other preamp I've heard in my house. And for the first time in more than 25 years of audio reviewing, I was hearing a component that caused me to enjoy my own reference system less when I reinstalled my regular preamplifier. That's one problem I don't face when I review entry-level bookshelf speakers!

If I could afford the Signature SE, I'd buy it. But that would mean convincing my wife to keep working another year before retiring. It would not go over well. Still, the day I removed the Signature SE from my system, to send it on to John Atkinson to be measured, my wife came home from work, looked at the rearranged components on my rack, and said, "What? The preamp's gone?"

Damn. I wonder what VAC's Statement line stage sounds like. . .

………Bob Reina

A cost-no-object, world's finest, bar none and with an aesthetic that positively celebrates the vacuum tube.
When State-of-the-Art means exactly this: A cost-no-object, world's finest, bar none and with an aesthetic that positively celebrates the vacuum tube.
 
Testimonials
 
"It is critical in manufacturing perfectionist speakers to use related components that reveal all that's possible; especially in resolution, tonality, dynamics and sound-staging. To this end we've evaluated and tried a vast array of the highest end equipment available. VAC's amplifiers and preamps have turned out to be references of the highest order, and not coincidentally, terrifically enjoyable to listen to" 
- Alon Wolf, owner Magico Loudspeakers
(Magico's speakers have won numerous top awards here and in Asia in the past few years and range from $22,400 to over $250,000)
 
Where are the testimonials? Fact is, VAC hand builds each component in such a labor of love, time intensive way and has enough of a 'diehard' following that there is usually a 8-12 week backlog of orders and no units available for review. Nor is there anyway to meet higher demand from a 'great review'. VAC is as non-commercial as it gets and the attention is on making the best gear possible, not the best reviewed gear. So stop on by for a demonstration and compare it yourself to other top flight amps and you'll understand; the Phi 300.1 is truly state-of-the-art, no second guess.
 
Overview
 
The VAC Phi 300.1a is an extremely potent amplifier guaranteed to transcend your previous ideas of reference amplifiers; majestic, commanding, totally harmonious with astounding definition and holographic imaging. It is based on a direct coupled input & driver circuit that results in the fastest, fullest, most detailed sound that  have ever achieved and you are likely to ever hear. The ambience and retrievel of reverb and decay information is particularly surprising.
 
Using eight beam power output tubes and a low-mu octal driver, this amplifier possesses an uncanny ability to reveal every nuance in a recording, while preserve the emotion and feel necessary for a truly musical performance. In addition to finesse, it has great power, impact, control, and a low electrical noise floor. This remarkable overall character makes it suitable for use with speakers ranging from high efficiency to the most difficult and demanding.
 
Technical
 
Its eight beam power output tubes yield 300 watts in bridged mono mode or 150 watts/channel in stereo mode at the choice of the user. Front panel level controls may be engaged to aid in balancing biamplified systems. Both balanced XLR and single-ended RCA inputs are provided. Triode operation may be selected at the flick of a switch. The chassis is machined aluminum, with the tubes beautifully showcased behind 0.75" acrylic glass. Also included are standard 12 volt triggers.
 
Both single-ended and balanced (fully balanced amplifier mode) inputs are provided. The chassis is custom machined 0.25" aluminum welded into a solid unitary structure, finished in metallic black paint. The 1" thick aluminum front panel is finished in hand rubbed silver metalic (or black) lacquer, with bias meter and tube adjustors that make it easy to maintain and optimize. Output matching taps are provided for 2, 4, and 8 ohm speakers.