Thrax Audio

State of the Art Audio to Die For out of Bulgaria
Unconventional State of the Art Audio components delivering Never Heard Before reproduced Music Performance

We do what we do because we are put off by the "good enough" approach and the monopoly of mediocrity. There was a time when sport was for fame and glory.

We do this to show that all technologies needed for amazing sound are there for anyone to use, although not cheap. If greed takes the back seat then components with six figure price tags will be just a bad memory, but with THRAX the Performance - Highly Musical.

Thrax Audio/Brodmann Acoustics @ CES - Key Kim - A key witness to a Great Sound
The elegantly finished Brodmann FS monitor loudspeakers were driven exquisitely by Thrax Audio of Bulgaria. The Thrax Audio Heros mono amps utilize a two-gain stage design using a single tube at the input stage. The Dionysos preamplifier uses a single gain stage with zero feedback and also utilizes a single triode tube at its input (review in works).  The MaximinusDAC boasts a universal DSP controlled 32-Bit/38 kHz discrete resistor ladder DAC.The sound was very natural sounding and it was smooth, rich and lively.

MONO & STEREO COMMENT on THRAX: 
"There are few high-end audio companies, that are operating on the level, that really works and stand out in my book of high-end audio dealings these days. Among these is definitely Thrax Audio from Bulgaria. I’ve had some insights into their business from the past experiences with the brand products, but my recent visit to the factory changed a lot. Seeing the dedication, R & D and most importantly the enthusiasm that goes into their product was an eye opener"

CONCEPTS:
The human vision, hearing and other senses are not absolute measurement devices. They compare the difference between a reference and the tracked signals, and it's changes over time. 

The hearing system registers sounds and requires some time to assess what they are. It then starts to track the changes giving less importance (losing interest) to long and sustained signals with no change. 

It adapts to the surrounding (residual) background and concentrates on the constant changes in signal properties. Your vision is attracted by motion or flashing lights in this exact same way. 

This phenomenon allows you to follow a conversation between two people in a noisy environment or listen to the voice of a singer undisturbed by a busy piece. In your office you realize how noisy it is only when the noise stops.

If the background is quiet the following sound appears louder and clearer. Anything different from the pitch-black background attracts your attention. Or if your hearing has adapted to a residual noise you start losing information (your brain does not pay attention to it). To make an analogy it is like increasing the contrast in a picture by darkening the background instead of increasing the brightness. The bright light will blind you and you will not see better, but removing the strenuous light makes your reference (black) stable and the picture becomes more vivid and sharp. It's like watching a movie in the cinema with the ambient lights on or off. Let us put this in the context we are interested in. Music is written with notes and pauses that represent sounds and SILENCE. The quality and quantity of silence in between notes is just as important as the pitch and timbre in the notes themselves. 

It is rather complex why we have all those artefacts in our precious music through the reproduction chain but it is immediately apparent when they are reduced, and simply amazing when they are almost gone. Serenity and expressiveness come to mind when you experience it. It just sounds right.

INSPIRATION:
The works of Japanese some of the tube gurus are a source of inspiration for us and the different approaches taken to achieve the same goal. Their attention to detail and manufacturing quality inspired us to TRY to do BETTER. The works and concepts of another Japanese designer came closest to the direction in which we were heading. Never implemented commercially, however, the designs of Sakuma San are a tough example to follow. Directly heated triodes with inductive loads seemed to deliver the effortlessness and tonal richness we are after. 

Later we would realize that the root of it all was Western Electric and their creations. Their amplifiers and speakers are something like Adam and Eve for high-end audio. 

Through those simple designs, music flowed seamlessly but with some shortcomings. Many tried to improve on those through the years, getting rid of most problems by unnecessary complication. The goal for improved music reproduction mutated into engineering competition in achieving meaningless target figures in areas alien to music and it's reproduction. It is a bit like specifying string weight and length in the piano. It is just irrelevant.

LEARNING FROM LEGACY:
Looking at quality goods, wines, and watches we see the same techniques used years ago are still in use today. Yet the well made modern products are incomparably better. 

We have all seen the glass piano and bodiless electric violin – again victims of technology perhaps. 

We try to use as much as possible of the knowledge accumulated in the field and blend it with our own experience and cutting edge high-tech available today, so that we may achieve what previous attempts have failed. 

There are superb designs out there by many reputable companies that reproduce sounds like us but few if any reproduce silence as good.

MOTIVATION:
Many years of exploration in the world of high quality audio passed in listening, recording and comparing. Vast resources were wasted on “superbrand” products before we realized we can't buy the product that satisfied all our needs and felt the need to develop our own audio components. We gained experience with all available technologies and amplification circuits making headlines through the years and gradually filtered them down to a list of worthy contenders. 

Peoples prejudice is the fuel driving most manufacturers marketing departments. Capitalizing on the customers lack of knowledge by trowing at him terms and figures that are absolutely irrelevant to a units performance and claiming benefits unrelated to the above. 

We found numerous high-end products which promised the world, but most of them seemed to tell a different story upon auditioning. Some exhibited very good qualities but severely lacked in others. 

Some products carried true innovation but these inovations were usually limited to part of the whole making it no better than the average. Ingenious approaches coupled with off-the-shelf peripherals and bad manufacturing quality was the norm, as well as a lack of understanding of the whole system. 

We listened - we researched – and this led us in a strenuous 2 year R&D project in our own lab evaluating amplification topologies and circuits. Numerous prototypes were built, studied, and some destroyed until a pattern and a theory emerged. 

This was followed by yet another year of hands-on research and tests on the influence of various components and their qualities on sound, involving thousands of man-hours of auditioning and comparisons. 

We spent a considerable amount of time on mechanical construction and manufacturing methodology (this being clearly visible in our components). Vibration control, electromagnetic and electrostatic shielding, contact potential and many others followed. What we did had to be consistent and reproducible. 

We have not discovered a loophole in the laws of physics. What we found is that people quickly forget the achievements of times past, just to "discover" them again at a much later date. It is all there, you just have to put it together. We don't believe patented ways of heating water will make the difference. We look for the simplest meaningful legacy solution, find its flaws (usually wrong assumptions) and fix them if we can. It does not matter how much better a modern solution is if it is based on the same flawed assumptions and makes the same errors but better. 

Taking advantage of available 21st century technologies and materials allowed us to achieve what early designers called fiction. 

True to our beliefs we decided not to re-invent the wheel, but used the works and experience of the very best and implemented their knowledge in our product. It took a lot of time and tests to determine where the truth lied.. We do NOT build our own components but we buy them from the people that make them better than anybody we know (and we know a lot). And as for the rest, which we could not buy at the required quality level, we manufactured those components ourselves. 

We are probably one of the very few companies that go to this extent. We don't use a supplier's line of components for convenience but we use only the best part available for the specific design. For example, Plitron in Canada makes the transformer and choke in the Spartacus power supply and Tamura in Japan makes the signal handling ones. In Dionysos the honor goes to Lundahl for power and Hashimoto for signal. The same is applicable for tubes and other components. We could write pages upon pages as to why each component in our products is there, and why it was chosen. 

Actually, there is no trick, no magic. It is a complex function of knowledge, attention to detail, common sense and an open mind that gets you there. 

I hope what we came up with pleases your senses and sets you on a quest to seek those qualities in all products. 

Enjoy......
Rumen Artarski
(President)

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Featured

TX 13 TT YATRUS
Price on application
NEW PRODUCT RELEASE NOV 2018:The steady growth of Analog replay and the introduction of ever more complicated replay systems set us on a task to pack all the performance achievable today with a most...
Unique vibration-free direct drive brushless DC motor with integrated bearing for the smoothest...

All Products

DACs

TX 01 DAC MAX
NZ$ 55,995.00 ea (incl. GST)
MAXIMINUS Universal DSP controlled discrete resistor ladder 32bit/384kHz audio DAC - This is the original multibit DAC concept with the most sophisticated implementation and highest precision....
Multibit conversion25 bit resolution4 quadrant sign magnitude operation8 inputs (6 +2 optional)...
EXTENDED REVIEW: Rumen Artarski is a hunk of a man. Tall, handsome and ramrod-straight. He...
DACs

Power

TX 01 PC BLU 15
NZ$ 1,750.00 ea (incl. GST)
Power
TX 01 PC BLU 2
NZ$ 2,500.00 ea (incl. GST)
Power
TX 02 PC BLK 15
NZ$ 4,995.00 ea (incl. GST)
Power

Phono Stages

TX 02 PS ORPH
NZ$ 40,995.00 ea (incl. GST)
Orpheus Phono Phono Pre Amplifier with LCR RIAA equaliser - The phono preamplifier is responsible for extracting the last bit of information from the cartridge by providing optimal loading while...
Built in step up transformerAutomatic cartridge gain and loading seletionProgrammable gain and...
EXTENDED REVIEW: There are few high-end audio companies, that are operating on the level, that...
Phono Stages

Preamplifiers & Line-stages

TX 03 PA DION
NZ$ 40,995.00 ea (incl. GST)
Control Amplifier with remote - Dionysos is a remote controlled single triode transformer coupled line level amplifier.  The control amplifier is still the centrepiece of each high-end...
Accepts both balanced and unbalanced input signals on RCA and XLR connectorsSwitches ground plane...
EXTENDED REVIEW - MAXIMUM ATTENTIONAnother rare ultra highlight of 2013 arrived. Rumen Artarski...

Integrated amplifiers

TX 04 AI ARES
NZ$ 20,995.00 ea (incl. GST)
OPTIONAL PHONO & DAC & STREAMER:With Analog replay growing in popularity the addition our optional new RIAA module to the input board converts the first RCA input to a Moving Magnet and...
ARES & ENYO Common features: Analog inputs module- relay based 3xRCA and one XLR input selector...
Integrated amplifiers
TX 05 AI ENYO
NZ$ 20,995.11 ea (incl. GST)
The Thrax Enyo is mounted on a single chassis and would be defined as a complete audiophile system with the sound you want and the features you need. The set has two stages of power to valves...
ARES & ENYO Integrateds common features: Analog inputs module- relay based 3xRCA and one XLR...
Integrated amplifiers
TX 06 AI DAC ONE
NZ$ 3,995.00 ea (incl. GST)
OPTIONAL PHONO & DAC & STREAMER PLUG-IN BOARDS:With Analog replay growing in popularity the addition our optional new RIAA module to the input board converts the first RCA input to a Moving...
Integrated amplifiers
TX 06 AI PHONO
NZ$ 1,995.00 ea (incl. GST)
OPTIONAL PHONO & DAC & STREAMER PLUG_IN BOARDS: With Analog replay growing in popularity the addition our optional new RIAA module to the input board converts the first RCA input to a Moving...
Integrated amplifiers
TX 06 AI STREAM
NZ$ 1,995.00 ea (incl. GST)
OPTIONAL PHONO & DAC & STREAMER PLUG-IN BOARDS: With Analog replay growing in popularity the addition our optional new RIAA module to the input board converts the first RCA input to a Moving...
Integrated amplifiers

Power amplifiers (Stereo & Mono)

TX 07 AM HEROS
NZ$ 62,995.00 pr (incl. GST)
Class A Hybrid - tube/fet amplifier Heros is a unique and very unusual two stage hybrid transformer loaded amplifier marrying old concepts with latest technology. The numerous benefits from...
Tube amplifier architecture with simplest signal pathTransformer coupled input and outputJFET/...
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TX 07 AS TERES
NZ$ 35,995.00 ea (incl. GST)
TERES - TRANSFORMER COUPLED HYBRID POWER AMPLIFIER Teres is based on classic tube amplifier topology. Tube clarity and tone with might and power. Unusual but true...
Audiophile long life input tubeSilicon carbide rectifiersShunt regulated power supplySolar cell...
TX 08 AM TERES
NZ$ 55,995.00 pr (incl. GST)
Teres is based on the architecture of Spartacus. Single ended tube input stage loaded with a phase splitting transformer controlling 2 separate single ended amplifiers out of phase for output. Tube...
- Tube amplifier architecture with simplest signal path - Transformer coupling of stages- Special...
EXTENDED REVIEW: Thrax Audio - TERES Power amplifier + LYRA loudspeakers
TX 09 AM SPAR300
NZ$ 139,995.00 pr (incl. GST)
Spartacus is a statement. Demonstrating what can be achieved with modern directly heated triodes, advanced magnetic materials and the application of 21st century technology to a classic concept....
Custom current production tubes for long lifeKR PX25 input/driver tubeEML 520v3 output tubes70w for...

Book Shelf/Stand Mtg

TX 12 SS LYRA
NZ$ 24,500.00 pr (incl. GST)
Lyra is a unique 2 way speaker system. It features a new breed of high frequency driver loaded with a very special horn system, complimented by 2 magnesium diaphragm mid/bass drivers in a all...
EXTENDED REVIEW: Thrax Audio - TERES Power amplifier + LYRA loudspeakers
Book Shelf/Stand Mtg
TX 13 SS LYRA ST
Price on application
Book Shelf/Stand Mtg

Turntables

TX 13 TT YATRUS
Price on application
NEW PRODUCT RELEASE NOV 2018:The steady growth of Analog replay and the introduction of ever more complicated replay systems set us on a task to pack all the performance achievable today with a most...
Unique vibration-free direct drive brushless DC motor with integrated bearing for the smoothest...
Turntables

Reviews

Thrax Dionysos received Mono and Stereo most prestige Uber amp award for preamplifier that I though I'll won't gave out anytime soon if at all.
Matej Isak

SUMMARY REVIEW: I wrote this review in a bit different way. With Thrax products under review I wanted to share how special and different they are. As products in league comes rarely on market, I felt a need to present them as special and unique.

If any other company would packed so much high priced modular parts and add on all the R & D of Thrax Audio Dionysos would cost a fortune and quickly jumped into the territory of sky high priced preamplifiers like Kondo M1000 etc. You can rant as much as you want with my next statement, but at given price Thrax Dionysos is an actual high-end audio bargain. If we only break down the parts cost and quality of chassis you'll will quickly gave a wake up call for most ultra-high end companies. Money have to come from Rumen Artarski other operations. I highly and openly respect this.

Thrax Dionysos is one of the best if not the best (when implemented in a right system approach) preamplifier currently in production. Yes, quite a bold statement. With almost mind boggling internal architecture that paves the respect to the past and incorporate contemporary solutions Dionysos shifts the paradigms of what is possible when dots are connected in both researched and audible way. This preamplifier now only shows, but screams loudly how many man hours, passion and attention went not only in inner and outer design, but into an actual listening.

EXTENDED REVIEW - MAXIMUM ATTENTION
Another rare ultra highlight of 2013 arrived. Rumen Artarski company Thrax captured my attention during the shows and getting to know their philosophy more deeply via their website and correspondence with Rumen. There was something so different and "right" about it that dragged my attention again and again toward their products and philosophy.

FIRST ENCOUNTER
As I often stated, everything start from the first encounter; namely the shipping boxes, packaging etc. I really love when things are done right and in the best manner. Following wooden packagin further on, everything associated with Thrax product was refined and on the level I wish most companies would present them selves and their products. In ultra high end league, this is actually a must, but mostly fail to deliver. Why exactly? Dedication, pride of own works, respect for customers ...

Packing, manuals components design... All over achieved! Thrax Dionysos preamplifer aesthetics are a true piece of modern industry art. I always loved statement product in a state of the art enclosures, but Rumen really went far beyond ordinary in both inner and external design. High performance electronics executed electronically and visually in trueartisan way. This is a Thrax language of experssion.

Heros monoblocks are of the same calibre. With three dimensional looks and monument aura those are one of the best looking power amplifiers if not the best I'v seen! Period! And they sing!

PHILOSOPHY
Thrax Audio philosophy and approach strongly correlates with my inner clock and how things should be made according to my understandings and feelings about ultra high-end audio. From tube rectifiers, chokes, TVC's, best materials being used, simplicity of signal, remote, quality of build etc.

Here below are just three of their reminders and wake up calls to consider, but I strongly urge you to take time and go through Thrax Audio home page for their complete views. They are not there only to entertain, but they actually educate or reminds us on quite few important points:

Transformers. Why no body does that – and why they do only a partial job.
Transformers don’t measure that well. They have limited bandwidth and rising distortion at high levels and low frequencies. All those shortcomings are true, but would seem to be substantially better performing in dynamic conditions than ANY op amp. The effect is jaw dropping not subtle.

Why do we use triodes?
Audiophiles have been led to believe through published measurements at maximum output power and uneducated reviewers that single-ended triode amplifiers produce vast amounts of harmonic distortion. As a matter of fact triode vacuum tubes are by far the most linear amplifying devices in existence today. They produce the least amount of distortion, and that distortion is predominately second harmonic, which is the least obtrusive type for the sound. By contrast, pentodes produce greater distortion, and the third harmonic tends to dominate. A transistor looks at best like a very bad pentode.

Bring theory to practice – no feedback.
It is logical that a signal passing trough and amplification stage will have some distortion added to it. (In our case this will be almost only second harmonic.) Passing trough the next stage we will add distortion to the distortion generating a minimum amount of fourth order distortion and so on. (Pretty much like the effect of feedback described above)

Consider now the following: the usual preamplifier (tube or solid state) has 3 stages (input buffer, gain stage, output buffer), then the simplest power amplifiers have 4 stages (input, phase splitter, driver, output buffer ). And all this is dependent of the signal amplitude via an extremely nonlinear function.

In order to minimize this effect the preceding stage of any amplification stage should have at least 2-3 times lower distortion than the latter. (Would that be possible when we have 7 stages in the signal path?) Minimizing the number of stages reduces drastically the order of distortion and its inter modulation products.

The sonic result is vastly improved transparency and speed.

Our products feature the minimum sensible number of stages implemented with the most linear devices possible operating in the closest to theoretically perfect operating conditions achievable.

Result? You be the judge!

INSPIRATION
All great artisans never hide their inspirations. Many of us share the respect for Japanese audio legends and their heritage. They did rewake the magic of tubes (Triodes) and approached the creational stage with their cultural norms. Those norms makes them so different and in my terms better then most other designers. It sets the artisan way. As they created a legend they followed the legends. Thrax Audio elaborate shortly:

"The works of Japanese tube gurus are a source of inspiration for us are the best examples of the Japanese vacuum tube art currently in production and the different approaches taken to achieve the same goal. Their attention to detail and manufacturing quality inspired us to TRY and DO BETTER and do better. The works and concepts of another Japanese designer came closest to the direction in which we were heading. Never implemented commercially, however, the designs of Sakuma San are a tough example to follow. Directly heated triodes with inductive loads seemed to deliver the effortlessness and tonal richness we are after."

THE ONLY WAY
For me there are only two ways to ultra high-end heaven (with one or two exceptions, think Excalibur). Pure A class solid state or best executed tube circuits often or as a rule in A class. Outside of this territory products might sound fine and even above good, but never great in the ultimate sense. It seems that some rules of basic understanding must be followed to achieve state of the art high-end reproduction. And a talent to recognise and implement them.

It is my joy and pleasure to see and hear Thrax Audio venture going totally out of the box and above all trends to create their products in a stunning audible way. This is what  true high-end dedication means.

PURE AND PERFECT
I'm perfectionist by nature and love refined manufacturing combined with the great industry design. Both Dionysos and Heros are an example of what ultra high-end components should look and feel like. From handy remote, that reminds of Mobiado mobile phone to fine artistic details of Dionysos front plate. If you cannot appreciate meticulous CNC work and finish of this preamplifier then you must have other issues rather then respect for finest craftsmanship. I can spot the anomaly in design within seconds. It's just how my inner clocks and aesthetic sensors work. Both gift and curse at the same time as it's hard to get pleased and satisfied. Perhaps it's even peculiar. But, the thing is i can spot the un-perfection from a distance and it irritates me like anything :).

I love premium feel of things regardless of product type. Thrax products are carrying premium feeling that radiates an instant feeling of proud ownership and substantial luxury. Not in a snob like way, but with a certain aura that clearly reveals the elegancy and profound taste of man behind the company. My urge for things being done right is so rarely addressed with most high end audio products that usually feel rather mediocre in their appearance and design, then something that cost like a car or house.

Dionysos preamplifier and Heros heros monoblocks are wonderful examples of not following the crowd. Not only with their aesthetics, but as you'll find out in next lines also with what matters the most. Sound and music!

SWEET INTOXICATION OF MUSIC
I'm an indépendant and without any need to flatter anyone or follow up to advertising money to justify my writing. I can simply write through my passion and freely choose what to test and write about. Mostly I'm after the stand out products that boil my blood. Those who deliver music in its purity and potency. In that search I'm not bound to the price restriction. Both above and below. Thanks God!

Along Kondo Audio Note Japan and Robert Koda so far I simply didn't stumble upon the electronics that could ewoke such an unique musical impact as those two companies can project. Thrax joins them with big pace and it seems that even transcend at few points of Kondo unmistakable delicacy of intoxication.

Even from the first few notes being played through the Thrax Audio Dionysos preamplifier and Heros monoblock combination I was being shot directly into the vein with what Dionysos and Heros could present. A true blissful venom :). The sweet unstrained flow of music presented in a way of Monet and Degas witty view the world. Full of colour vibrancy and feeling of being there. And most importantly with the impact that last and stand continuously. A lot of high-end audio components might impress you at first glance. When you return to the listening, their initial impression fades. Through my listening notes that never happened with Thrax and I'm as excited with the music flow as I was on the first day. That should tell something right!?

With Thrax combo intimacy of sound and musciality hits you at such scale that leaves most of the gear of current high-end market light years behind. Bold statement right!?  Here are at workings something that few seems to understand or even write about. Not that I feel egocentric of special, but as I don't have to think in narrow or guided way perhaps this gives me a better position. And I'm used to high-priced high performance gear. I don't get scared or confused easily.

Thrax evoke the energy of motion. The purity of music untouched and so potent in its power to interact with listener without borders or constraints. At stake...  It's not only a matter of electronic design being used or implemented, but a subject of art and culture. The fact of the one's view of things general and particular. Choices being made and implemented.

Both Dionysos and Heros give such an impact and it feels so right. How is then that some fail to understand such products. Simple. People get scared of emotional potency and exchange! Over my twenty some years I've seen and heard quite an array of what supposed to be the best of the best. Based on numbers and some reviews those might hold some wicked titles, but at primal role of music reproduction at highest level they most fail to follow up those claims of state of the art. Ultra high-end is not a matter of background listening visionary of most. It's to be experienced directly and non altered. I know live and acoustical music by heart and play few instruments. Being in constant reset of subjectivity keeps me focused and objective. When it comes to the highest judgments I do think its a must to set a certain level of performance. Ultra high-end audio is a science by itself. It takes efforts to create those exceptional devices and it also takes mileages and efforts to understand and recognise them. Like with state of the art food, wine or horology. You cannot become an artisan or distinguish between the mediocre and the best in an easy way. It takes time and dedication on both fronts.

MUSIC
There is something special in the way that few of true state of the art products behaves. It got to do especially with inherited power of music. How it connects with us on the sublime level where things are on the emotional plane and far away from technicality being main reasoning act. It's true, that knowing music scales, history and philosophy helps in appreciating music more. Like with like an art.  It adds to experience, but not by default. It enriches you. Once you discover the historical time travel anchors of scales, movements, passions and pains behind the roots of past musical creations the primal impact is even more direct. Perhaps even poignant to a degree based on music material being listen to. But, for true emotional exchange all those variables are not needed, but they're welcomed.

We can argue a whole day long or until the cows go home about how certain audio component do or don't connect us more intimately to the core of performers and their intimate world, yet something do happen with certain audio reproduction devices. What is this exactly we fail to measure and I doubt we ever will, but we can understand a little portion to a certain degree with the overview of the technology being used. Of course when right strikes being taken. Not blindly, and in most cases not straight of the book.

Our expectations towards ultimate playback should be sky high. As prices. Sharp and direct. In the sense of ultra high end audio we're not buying into luxury segment, but a luxury performance that raises all the bars. I highly enjoy the complexity of any extraordinary design, but if it's only an outhere shell then what's the point. There are to many of such jewellery boxes out there. What I want and hanker for is an extraordinary musical box. Thrax made both wining strikes. With performance and looks. As mentioned above Dionysos looks like no other preamplifier. It's an art form of industrial design being taken seriously and above ordinary. It act as statement in physical appearance and sound performance. In a sense this is a true functional art for the music enjoyment of highest calibre. With Thrax form follow function and vice versus. Quite rare and wicked example :).

ANALOG TRUTH
Just in time I received Chad Kassem latest version of Getz/Gilberto Girl from Ipanema LP on 45rpm. Now if you need to buy one album per year here is your desert island choice. As with Acustics Sounds Analog Production of Nat King Cole Love Is A Thing analog is as great as ever. Some of the latest analog reissues or contemporary recordings like Norway's 2L digital to vinyl releases brought such a high performance to vinyl, that digital simply watch the burning smoke trail left behind by few miles. If you want to reveal a true potential of any given system then full state of the art analog front end will show the truth. Thrax combination is most enjoyable one brand system I have had pleasure to listen in my demo room. I put a lot of smilies in my listening notes and clearly noted my enjoyment of music and forgetting about the world.

I always do a reality check with the LessLoss set of product. They are my "trade standard" for testing the refinement of things. DFPC power cables quickly show the level of importance of quality cabling on any device. With Dionysos and Heroes the impact was not subtle and it only further showed the true capability of both devices. Analog is my medium of preference for reference performance and this is also where the LessLoss Firewall shows its sublime workings. Combining all this, and with an added Blackbody as Cherry on Top, the neutral performance was made clear. As written in my previous reviews of LessLoss products, they bring balance to performance and show the real potential of any given gear. With both Thrax components and LessLoss in a system they really enter the realm of state-of-the-art replay.

TRUE HEROS
As with Robert Koda Takumi K-10 Thrax Heros pulled the trick of illusion where one loose the objectivity regarding technology being used. In a blind test you cannot figure our if Takumi K-10 is a solid state or tube preamp. It holds all the attributes of tubes, but with the advantages of solid state. I can relate in a same way with Thrax Heros mono blocks. With the delicate power that some tube based power amplifiers might lack, Thrax Heros acted like no solid state or tube amplifier. They actually didn't act as any other power amp I heard. They've gone beyond solid state pure A class  sweetens and bring that natural there dimensionality and sense of space from tubes. A daring and puzzling combination, but it worked far beyond of what I expected. Remarkable!

In the upper echelon there are quite few solid state amplifiers that uses a pure class A at their heart core. Take Gryphon, Vitus etc. for example. While they performance brings certain intimacy nothing compare to the purity of Thrax Heros. They don't strain music in any way with dynamic imprint that still take away the "full magic" as with those establisehd pure Class A amps. Heros actually liberate music from solid state "cuffs".

Thrax Audio Heros looks different, perform different and act different. I can imagine only one amplifier being taken to the other shore of things beyond and that's Robert Koda Takumi K-70. I haven't listen to those monoblocks yet, but they're coming for a review in due time. 

Heros are not about power but about energy in motion. Its the effortless flow of music that makes Heros so darn warm hearted. You'll get struck by the intimacy and limitless natural nuances when music is being played. Especially with live acoustical recorded music, where one can instantly find and hear the what makes amp performance so elevated. 

THE DIONYSOS
Thrax Dionysos is a true ultimate component that you build your system around. You can start with it and elaborate when time and funds allow. Its performance goes ming boggling above the given price and fluidity and emotional impact makes you rethink about some of those pricey Japanese products. 

If Dionysos resembles the language of Rumen Artarski then all my respect and ego bow down to his efforts. This preamplifier is the labour of respect and love for music and all around approach with premium feeling makes one desire it even more. 

You may execute your need for branding, but there is no way to logically and emotionally pass the Thrax Dionysos when you're in the need of system change or in a hunt for state of the art preamplifier. Dionysos redefine the price structure and audiophile money being spend. Even when money not being subjet matter, you'll have the hardest task to find a competitive preamp. 

Like with IWC, Patek Philippe, Rolex etc. The feeling of handling things around Dionysos is prestigious and refine in most ergonomic way. Everything makes sense and I simply love the clear, clutter-less front plate without any prints. Anyhow. In few strikes you'll know your way around and enjoy operating it with ease.

In an Apple kind of way there are no visible screws or bolts on chassis. Design like this takes time and dedication. Result is an unmistakable aura which makes Thrax flagship preamplifier unique and stand out from the crowd. 

Thrax Dionysos received Mono and Stereo most prestige Uber amp award for preamplier that I though I'll won't gave out anytime soon if at all. 

Conclusion
I wrote this review in a bit different way. Above are links connected to the operational manuals and specifications for both products. With Thrax products under review I wanted to share how special and different they are. As products in league comes rarely on market, I felt a need to present them as special and unique.

If any other company would packed so much high priced modular parts and add on all the R & D of Thrax Audio Dionysos would cost a fortune and quickly jumped into the territory of sky high priced preamplifiers like Kondo M1000 etc. You can rant as much as you want with my next statement, but at given price Thrax Dionysos is an actual high-end audio bargain. If we only break down the parts cost and quality of chassis you'll will quickly gave a wake up call for most ultra-high end companies. Money have to come from Rumen Artarski other operations. I highly and openly respect this.

Thrax Dionysos is one of the best if not the best (when implemented in a right system approach) preamplifier currently in production. Yes, quite a bold statement. With almost mind boggling internal architecture that paves the respect to the past and incorporate contemporary solutions Dionysos shifts the paradigms of what is possible when dots are connected in both researched and audible way. This preamplifier now only shows, but screams loudly how many man hours, passion and attention went not only in inner and outer design, but into an actual listening.

THRAX Maximinus D/A Converter, Dionysos Preamplifier & Spartacus Power Amplifier review
Wojciech Pacuła (translation by Andrzej Dziadowiec).

SUMMARY REVIEW: CONCLUSION - A system is a sacred thing in audio. The one from Thrax is a real system, not merely a set of components. They all fit together perfectly, helping each other. I did not review them separately, but to understand what they are capable of on their own I listened to each one, comparing them against my reference components.

The DAC has a very warm, incredibly "analog" sound. It shows large phantom images and beautiful foreground. It sounds rather soft and does not offer a particularly deep soundstage. Its resolution is good, less so its selectiveness. The USB input works great, and the sound can be shaped to a large extent by the choice of digital filters. The preamplifier has a similar tonality, but is also more dynamic. It has quite a lot of "swing" to its sound, with a nice, soft attack. While the DAC gives the whole system its overall tonality and "sets" the soundstage, the preamp gives it some "swing" and binds everything together so that individual elements work in harmony. But I think it is the Spartacus that is the real star here. The monoblocks give everything else energy and build up the structure onto which elements transferred from the DAC and preamplifier are superimposed. And it is them that retain full calm driving even large speakers that present a complex load.

It is a system that offers a very versatile sound, particularly suiting small ensembles and good recordings that will come out very natural. Albums with poorer production are fun, too, and the Thrax tries to save them as much as possible, but when it is fed with something special, it warms up and plays music with real passion. And that is also how you listen to it, with a flush on your face. If you prefer large ensembles and like more drive and speed, you will either need to try out other speakers or look somewhere else to find more suitable electronics.

EXTENDED REVIEW: Rumen Artarski is a hunk of a man. Tall, handsome and ramrod-straight. He could serve in Special Forces or join the Honor Guard. He could be a grenadier or serve in the praetorian guard of the Caesars. There is some inner strength in Rumen—he is big, but not bulky or sluggish.

When he first wrote to me in 2010 I did not know him as much as I do today. However, the preamplifier that he sent for a review was outstanding, very much to my liking. Built with a heart, it looked like a pure-bred product from a large manufacturer that has for years mastered the production process and now can focus solely on the sound. The review appeared in "High Fidelity" in January 2011 and was the first publication on products from Thrax Audio outside its native Bulgaria.

Almost any encyclopedia confirms that a vital characteristic trait that was admirable in ancient Thrace, whence the company takes its name, was physical strength. I think Rumen would fit in perfectly there. The region, which was historically part of the Roman Empire, located on its eastern flank, is currently divided between three neighboring countries: Greece, Turkey and Bulgaria. It was the birthplace of Spartacus, the slave and gladiator who became the leader of a slave uprising against the Roman Republic in 73-71 BC, which attracted about 100 thousand people.

There is no denying that by naming his company after the Roman era and borrowing the names of his products from the Greek pantheon of gods and famous people from the Roman period he clearly identifies with them. Well, if you can boast such a long history, you just have to do that. The beginnings of Bulgaria go back to the 5th century BC, when Thracian tribes were united in the Odrysian Kingdom, subsequently conquered by the Romans. The region between the Danube River and the Balkan mountain range was organized as the Roman province of Moesia (6-9 AD). Rumen would fit in perfectly there, I'm sure of that

I have been waiting for four years to review the whole Thrax Audio system, which has recently been expanded to include a DAC. Now we have a complete audio system, from the Maximinus D/A converter, through the Orpheus phono stage and the Dionysos preamplifier, to the power amplifier, either the tube-based Spartacus or the hybrid Hero monoblocks.

Each one of them is a proprietary Thrax design. The company is located in Sofia, the capital of Bulgaria. All Thrax products are manufactured right there, from A to Z. Each one features interesting design solutions. The DAC is based on a DSP-controlled, discreet R-2R resistor ladder. It is a multi-bit design with the resolution of 25-bit and upper sampling frequency of 384kHz. The user is presented with a wide range of sound-shaping capabilities, which include selectable reclocking, two upsampling algorithms and four digital filters. The signal path is extremely short, with no output buffers or coupling capacitors. Instead, the output is transformer-coupled.

As a matter of fact, coupling transformers seem to be a Thrax trademark, and are also used in the input and output stages of the Dionysos preamplifier and in its volume regulator. The power amplifier has a transformer-coupled input and employs an interstage transformer.

As I've said earlier, the components are manufactured in Bulgaria. The workmanship is top notch. Perfect enclosures, beautiful inner assembly, very expensive electronic components throughout and microprocessor-based control are common features in all of them. Every company, regardless of its origin and experience, could be proud of such design and workmanship quality. Even the Japanese, although they have their own tricks and solutions, like the use of oil capacitors and copper.

A few simple words with…Rumen Artarski | Thrax | CEO

Could you tell us the story behind the Spartacus?

The concept for Spartacus came along after years of listening to the most famous single ended triode amplifiers. Our research pointed that the sonic character of the amplifier is defined by the driver stage and output transformer rather than by the type of output tube. The other crucial component is power supply.

So we set to design a better single ended amplifier by using the accumulated knowledge. We decided to use a driver that is much more linear than the output tube by using a directly heated triode there, namely the PX25, and taking the PSU to an extreme by implementing a constant current shunt regulator. This sounded fabulous but the amount of heat produced and moderate power output (30W) was not enough. The next step was to double the output stage and reverse the phase of one of the output tubes. This resulting current cancelation gave us the opportunity to use higher quality nickel transformers and doubled the output power. Lower current fluctuations meant easier load for the shunt thus reducing the extra heat output. The second harmonic cancelation in the output stage made the amplifier sound even better and again its sonic character is shaped entirely by the quality of the PX25 driver. It does not sound like a tube amp at all, it does not sound like solid state either.

And what about the Maximinus?

The Maximinus was born out of necessity. I have been a distributor for some top digital brands since 1996. I am used to top quality digital components, but after introducing our amplifiers there was a huge gap in performance between the best analog and hi-res digital front ends. We needed a D/A converter that would have an exemplary low level linearity and resolution. We acquired all the best in the available OEM designs but none came close to our reference. After a bit of research we came across MSB Technology and their discrete sign-magnitude Ladder DAC. This was conceptually the right thing to do. We contracted them to do a revised version of their current flagship for us. During the process of product development we designed a new PSU topology using our ccd/shunt concept and new input board, this sounded very good. The next step was to do our own output buffer. We bypassed the output opamp they use and that changed everything – it was as clean and natural as we could ever want. The question was how to get that perfect signal out of the board. Here we set to design a circuit around an output transformer, more or less like in the Spartacus. This provides the necessary isolation and impedance matching.

Does the Spartacus feature a fully balanced topology?

The Spartacus has a balanced input as it is transformer coupled but the driver is single ended giving the whole amplifier its special character.

Why do you use these particular tubes?

Emission labs and KR make some of the very best tubes in existence today. This is the 21st century implementation of old technology. NOS tubes are inconsistent in terms of availability and performance, so we decided it is worth the extra cost.

MSB has its own design concept of the USB input – which solution do you use?

The USB input board has been developed by George from JLsounds.com He has written all the s/ware and implemented special features not available in other implementations.

The Maximinus offers several digital filters... could you say something about them?

There are 2 upsampling algorithms and 4 digital filters. We could not decide on a single filter that sounds best so we left the option to the user to choose "their" version. The differences are quite big. Try them all and after that I will tell you which one is which.

Digital filters are one thing but upsampling is something else... do you consider the latter a good way of shaping the signal?

I would recommend it for CD but again is a matter of taste.

SOUND

Albums auditioned during this review
• Music For A While. Improvisations on Purcell, Christina Pluhar, L'Arpeggiata, Erato 4636203, CD + DVD (2014).
• Charlie Haden & Chris Anderson, None But The Lonely Heart, Naim naimcd022, CD (1998).
• Danielsson, Dell, Landgren, Salzau Music On The Water, ACT Music ACT 9445-2, CD (2006).
• Dire Straits, Brothers in Arms, Vertigo/Universal Music Ltd. Hong Kong 5483572SX, SHM-XRCD2 (1985/2011).
• Flairck, De Gouden Eeuw, Bonnet Records BOR 96016711, CD (1996).
• Jean-Michel Jarre, Revolutions, Dreyfus Disque/Polydor POLH 45, LP (1988).
• Jean-Michel Jarre, Zoolook, Dreyfus Disque/Polydor JAR4 5, LP (1984).
• John Coltrane Quartet, Ballads, Impulse!/Universal Music LLC (Japan) UCCU-40001, Platinum SHM-CD (2013).
• Lars Danielsson, Mélange Bleu, ACT, 9604-2, "ACT: Nu Jazz"", CD (2006).
• Laurie Anderson, Homeland, Nonesuch 524055-2, CD + DVD (2010); 
• Miles Davis, In A Silent Way, Columbia/Mobile Fidelity UDSACD-2088, "Special Limited Edition, No. 1311", SACD/CD (1969/2012).•
Pat Metheny Group, Offramp, ECM/Universal Music K.K. UCCU-9543, "Jazz The Best No. 43", gold-CD (1982/2004).
• Piotr Anderszewski, Piotr Anderszewski at Carnegie Hall, Virgin Classic 267291 2, 2 x CD (2009);
• ShowBand, Punkt styku, GAD Records GAD CD 013, CD (2014)
. Soundgarden, Superunknown, A&M Records 3778183, "Deluxe Edition", 2 x CD (1994/2014).
• Tangerine Dream, Phaedra, Virgin/EMI Music Japan VJCP-68867, CD (1974/2004).
• The Beatles, Abbey Road, Apple/Toshiba-EMI TOCP-51122, CD (1969/2000).
• The Handsom Family, Singing Bones, Carrot TopSAKI036, CD (2003).

The Thrax system is truly impressive. It is perfectly built, has well-balanced proportions and offers great functionality. Its metal enclosures sport the kind of finish befitting modern solid state amplifiers, which seems to stand in opposition to Thrax's tube soul. But only at the first glance. After proper installation and setup, the components blend into the surroundings, only occasionally marking their presence. The most dazzling of them are the monoblocks that make for the clou of this system.

However, to bring out this clou and be able to say something like that, the Spartacus need to be set up with the other Thrax components. The review concerned the whole Bulgarian system, but I also tried swapping the components one by one for those from my reference system. Each time I noticed a marked change and some sonic improvement. But I was always glad to go back to the original setup installed by people from RCM, the Polish distributor for Thrax, with a sense of relief and satisfaction of a job well done. The DAC, preamp and monoblocks would just "click" together into something better and nicer.

Playing tracks that are big on atmosphere, with clear interaction between the musicians which creates a "message", not only music, I found the Thrax system become more beautiful with every next track. Not that it looked or sounded bad to start with, that is. It's just that during the audition you slowly start to sink into whatever you're sitting on, and feel your shoulder and then face muscles relax. The presentation is incredibly dense and beautiful. The category of beauty is difficult to stratify and there are no clear indicators of what makes a thing "beautiful" because it changes over time. But I think that in a small group that belongs to a given segment of culture, for example among audiophiles, it is possible to agree on what is and what is not beautiful.

That is why it is so easy for me to talk about beauty in the context of Thrax. Part V from Salzau Music On The Water. Falling from Homeland. Mélange Bleu from the album of the same title. The whole of None But The Lonely Heart. And others. All these tracks were wonderful. Saturated and soft. And at the same time so packed with information on differences between the instruments that they felt natural. It's not about detail, because when we listen to live music we do not perceive details in isolation from context. The Thrax sounded the way you hear music at a concert, offering large musical planes without emphasizing the attack, and at the same time clearly enough to nicely compensate for the lack of visual aspect.

The system evidently cherished vocals in a special way. And solo instruments, like on the Platinum SHM-CD version of John Coltrane's Ballads. Discs of this type sounded better than they do on my system. At least in terms of depth within a given sound source or timbral differentiation. It did not apply to all CDs, which I will say more about later, but the sound was very similar to what I had heard before from the Ancient Audio Silver Grand Mono monoblocks. A similar softness was also characteristic of the Triode TRX-M300 Reference Edition monoblocks, although it was not accompanied by such outstanding resolution. A similarly saturated sound is also offered by solid-state amplifiers from Vitus Audio.

The overall tonality of the Thrax system was centered on warm midrange, although not limited to it. When a recording suggested it, the upper treble was open and strong. The bottom end, if only so envisaged by the production and mastering engineer, was strong, dense and accurate. Of course, accurate for a tube amplifier. But the dominant impression after the first minutes of listening was that of sinking into something soft, which indicates that it is the midrange that is most important.

The Spartacus, which is the most important contributor in this regard, has a good low frequency response. Most triode-based amplifiers I have heard (including pentode and beam tetrode designs) have a less controlled and more "saggy" sound. Many powerful amplifiers on the KT88, KT120 and even KT150 power triodes cannot fully cope with the deep bass extension of electronic instruments, and tend to round off the left hand of the piano and thicken the double bass body. The Spartacus also adds something of its own and cannot match the sound decay capability of the Soulution, but it is neither intrusive nor awkward in doing that.

Even a very deep bass extension on the recordings by Laurie Anderson or Lars Danielsson made no impression on the amplifier. The output current capability of the monoblocks must be impressive. Only the Ancient Audio amplifier is capable of something even more spectacular. But if you test your amplifiers using such speakers as the Sonus Faber Fenice (also known as "The Sonus Faber"), the Wilson Maxx3 or German Physics designs, you clearly know what you are doing. These are the speakers used by Rumen Artarski and his Thrax team in their reference system. Not easy to drive at all, particularly in the bass range. My Harbeth M40.1, although nominally the easiest to "move" in this company, are also very demanding. But even with them, the Bulgarian tube amp created very large phantom images, which is a sign of a great lower midrange and bass saturation, and showed good extension all the way down, only limited by the speakers themselves. The bottom end, below some 40 Hz, was slightly less energetic but it had no special consequences for the music. Only a direct comparison against the Soulution showed that, whatever we think of it, tube amplifiers are just no match for solid state in this range.

The sound of the Thrax system showed only slight coloration. Its overall tonal balance seemed fantastic and was reminiscent of that in my own system and in Tomek's system. If anything, it was rather on the warm side, or at least it seemed to be. My bet is on the latter. The sound was very clean and exhibited a fantastic dynamic and timbral differentiation between instruments. The Thrax built up a large soundstage, with very strong musical planes in front of the listener, and with excellent spatial aspects in counter-phase. Anderson's and Danielsson's albums that are rich in this type of information made me sit in a large bubble of sound.

It must be said that the foreground was so intense and palpable that it made the layers further down the soundstage seem quieter and less important. The background was neither muted nor too little expressive, but it simply did not draw so much attention as it does on my system. I needed to focus on the further planes to make them "come out", appear from the background. In a normal listen, when we let ourselves be carried away by the music, everything that is located behind the performers and sounds in the foreground becomes of secondary importance.

Everything written so far is very universal and will prove true with any musical material and the majority of loudspeakers. The Spartacus monoblocks have excellent speaker control, without showing any sign of a "tube" character. But they will not do anything that's not to their "liking." Their agility and energy, in the sense of rhythmic "punctuality," are fairly subdued. Electronica albums by Duda and Bilinski (the new Best of the Best is fantastic, including the LP!), rock music, such as the new remaster of Soundgarden Superunknown or the SHM-XRCD release of Dire Straits Brothers in Arms, but also more upbeat tracks by The Beatles, all sounded calmed down and smoother than they should have. Small ensembles and slower compositions came out brilliant, as if played live, with suspended "air," proper pause and silence, and fluids between performers. Anything heavier would bring me back to a polite, gentle sound. As I've said, the amplifier has a high current output capability and does not run into audible clipping. It has therefore more to do with the structure of sound built in a certain way and results from designers' choices and the inherent limitations of technology. It sounds as if Rumen and the people from Thrax knew exactly what they wanted to arrive at, and they managed to do it in great style.

CONCLUSION

A system is a sacred thing in audio. The one from Thrax is a real system, not merely a set of components. They all fit together perfectly, helping each other. I did not review them separately, but to understand what they are capable of on their own I listened to each one, comparing them against my reference components.

The DAC has a very warm, incredibly "analog" sound. It shows large phantom images and beautiful foreground. It sounds rather soft and does not offer a particularly deep soundstage. Its resolution is good, less so its selectiveness. The USB input works great, and the sound can be shaped to a large extent by the choice of digital filters. The preamplifier has a similar tonality, but is also more dynamic. It has quite a lot of "swing" to its sound, with a nice, soft attack. While the DAC gives the whole system its overall tonality and "sets" the soundstage, the preamp gives it some "swing" and binds everything together so that individual elements work in harmony. But I think it is the Spartacus that is the real star here. The monoblocks give everything else energy and build up the structure onto which elements transferred from the DAC and preamplifier are superimposed. And it is them that retain full calm driving even large speakers that present a complex load.

It is a system that offers a very versatile sound, particularly suiting small ensembles and good recordings that will come out very natural. Albums with poorer production are fun, too, and the Thrax tries to save them as much as possible, but when it is fed with something special, it warms up and plays music with real passion. And that is also how you listen to it, with a flush on your face. If you prefer large ensembles and like more drive and speed, you will either need to try out other speakers or look somewhere else to find more suitable electronics.

Review Methodology

The system was reviewed as a whole. Connection was via RCA interconnects; the individual components are single ended although they can also be hooked up using XLR cables. The amplifier gain was set to "Low." The DAC offers many opportunities to change the sound. I settled for Upsampling off, Reclocking on and Filter no. 4, occasionally changed with Filter no. 2. The upsampling adds warmth to the sound and emphasizes the midrange. However, it happens at the cost of lower resolution and clarity of the top and bottom end. The UPS1 setting is more focused, with smaller sound, while the UPS2 is more spacious and with less focus on instruments. The digital filters differ significantly. Filter 1 resembles a classic brickwall-type filter, with a sharp roll-off and symmetrical ringing before and after the transient. It results in a less "alive" sound, rather devoid of emotion. Filter 2 is deeper, warmer but very open. Filter 3 resembles something between 1 and 2, and did not evoke any special emotion in me. I liked Filter 4 the most, with its warmer tonality and best body. It is the one that particularly favors the foreground, but is also the only one that offers outstanding volume and palpability. It treats further musical planes with less attention. Reclocking results in better three-dimensional bodies, nicer textures and better bass.

During the review, the amplifiers were placed on the Acoustic Revive RST-38H isolation boards, and the DAC was sitting on the Franc Audio Accessories Ceramic Disc Classic feet. All components were powered via the Acrolink Mexcel 7N-PC9500 power cords, plugged into the Acoustic Revive RTP-6e Ultimate power strip. The signal was fed from the transport section of the Ancient Audio Air V-edition and, via USB, from a HP laptop equipped with Windows 8/8GB RAM/128GB SDD/JPlay player.

DESIGN

The build and finish quality of the Bulgarian components is perfect. A few of my friends, who saw them at my place, could not take their eyes off their ideal enclosures, nice proportions and details. The enclosures are made of thick aluminum plates with sanding finish. I doubt that any Polish manufacturer would be able to match this kind of aluminum enclosure finish quality. The DAC and preamplifier share the same chassis design, obviously with different front and rear panels. The Spartacus in turn shares the chassis with the hybrid Heros monoblocks. All components are equipped with rather small but well-designed feet. They are made of POM material, used in turntables, and mounted to the chassis with vinyl screws.

MAXIMINUS
The Maximinus front panel features a few push buttons, a small knob and large green LED display. The display lights up only when controls are being used, then goes out to reduce the noise it generates. I would prefer more user control over this. The display shows the currently selected input as well as its frequency and word length, and menu settings. Interestingly, the signal fed from the Philips CD Pro2 drive is indicated as 17-bit rather than 16-bit. One of the push buttons is used to "wake up" the DAC or put it back to sleep. Another one activates the mute mode. The other buttons and the knob are used to navigate through the menu.

The very good, rhodium-plated RCA connectors are from Cardas. In turn, the gold-plated XLRs come from Neutrik. The analog outputs include a pair of RCAs (single ended) and XLRs (balanced). Digital inputs are a plenty and should be enough for even the most advanced systems: 2 x RCA, 2 x TOSLINK, 2 x AES/EBU, USB (optional), and LAN—intended for a future expansion and now secured with a plug (bearing the Neutrik logo), probably to connect to a computer in the local network, using the DLNA protocol. Of course, there is also the power socket with an integrated mechanical switch.

Unfortunately, I did not manage to completely disassemble the units, as they are assembled "on the back." From the bottom, I could only see high quality power supplies, separate for each section: D/A converter, master clock, DSP and logic circuits. However, Rumen had sent images where you can see what's what. The main board is made by MSB Technology, and includes four mono converters built on discrete R-2R resistor ladders controlled by two DSP chips from Analog Devices. There are four converters, two per channel, since the circuit operates in a balanced mode. The converters used are the most expensive Platinum Signature model. This is the most labor-intensive and expensive but probably also the best type of DAC design. Using DSP also made it possible to implement proprietary digital filters. Thrax gives the user lots of options and possibilities with four filters, two types of upsampling and two reclocking options.

The whole circuit is ultra-minimalist, because the converters are not coupled to gain and buffer stages, normally used in DAC designs. There are only impedance matching transformers and that's it. All digital inputs are also transformer coupled.

USB input is optional. It is housed on a small PCB that brims with great design solutions. It is mounted together with a very large, thick aluminum plate to isolate the USB input from the rest of the DAC circuit. The optional USB input has been designed by JL Sounds which I had never heard of before. It is based on a reprogrammed XMOS chip, surrounded by fantastic quartz oscillators—one for the input and two for the output signal, separately for the 44.1 and 48kHz sampling frequency families. There is also a reclocking circuit to eliminate jitter. The USB board accepts the signal in asynchronous mode, up to 32-bit/384kHz, which makes it DXD capable. It can also handle the DSD signal (via the DoP protocol). The USB board provides I2S and S/PDIF output. To isolate the rest of the DAC circuit from the incoming computer noise, the I2S output (and S/PDIF, if it is used), oscillators and reclocking circuit are galvanically isolated from the XMOS circuit and USB input ground. The user can also use an outboard master clock. I have maybe seen an equally sophisticated USB input circuit once or twice in my life.

DIONYSOS
My review of the preamplifier was published in January, 2011, in High Fidelity No. 81. I think I have exhausted the subject, so let me now simply repeat the most important aspects of the Dionysos design.

The front panel is shaped similarly to that of the Maximinus, with a recessed area for the push buttons, display screen and volume knob. The buttons include standby, tape out and absolute phase control. The latter is thus easier accessible than in the DAC, where absolute phase can only be changed from the menu. The switchable tape output is different than a traditional tape loop that introduces additional contacts to signal path all the time. Here the main signal path is kept as short and simple as possible, with additional features added ‘around' the signal path to minimize their interference with the audio signal. With the Tape out activated, the tape output connectors are transformer buffered straight from the currently selected input at unity gain.

The rear panel is excellent and features high quality RCA and XLR connectors. The latter are included for user's convenience, as the preamplifier has single-ended circuit topology. The balanced signal is desymmetrized in the input coupling transformers and re-symmetrized in the output. There are four single-ended and two balanced inputs. One of the inputs can be set to bypass for integration in home cinema systems, with the input signal looped through to the output. There is also a pair of tape out RCAs, ground/float switches for all RCA input and output connectors and four pairs of outputs, including two RCAs and two XLRs.

In a separately milled recess sits the IEC socket, a mechanical power switch and a level set button. The latter can be used to set the level of any chosen input and place it in bypass mode. This input's LED will then turn red. The voltage level is set in internal memory and won't default with power-down. Unity gain equates to 24 on the display.

Electronic components have been selected for their sonic quality rather than their origin. Hence, a lot of them are military grade components from the former Soviet Union, like the excellent oil capacitors in the power supply. The PCB with the amplification section and power supply is bolted to two blue-anodized aluminum bars which themselves are not bolted to the bottom plate but the chassis sides. The Maximinus sports a similar design. The entire power supply also mounts to the side panel, with a nice big transformer, NOS oil capacitors from the USSR and a very big Lundahl choke. To the other side panel bolt two big Japanese Hashimoto Electric input and output coupling transformers, and the volume transformers enclosed in catchy solid metal cans. Transformer-based volume control is very important for me, because it is also used in my Ayon Audio Polaris III preamplifier. These supermalloy transformer attenuators from SAC Thailand feature SILK winding technology. Connection to the main board is via Oyaide cables with high quality PCOCC-A wires. An internal heat sink divides the PCB in two parts, power supply and amplification circuit. In the latter we only have one 6N6P (6Н6П) twin triode. Next to it we see a few high-quality passive components including Wima coupling capacitors and precision resistors. To the side there is an additional PCB with two rows of relays to key the individual TVC sections. On the other side of the heat sink divider sits the power supply with the 6C4P-EV (6Ц4П-В) tube rectifier and a voltage stabilizer using the SG15P (СГ15П). On the tubes we can see ferrite muffs for EMI shielding. The heater circuits are rectified by discreet solid-state bridges separately for the power supply and amplification tubes.

SPARTACUS

The Spartacus is a stereo power amplifier built as a pair of monoblocks. It sports a fully tube circuit, including the power supply. This powerful machine is capable of delivering 70 Watts in class A! The tubes have been selected on the basis of their sonic qualities and come from various manufacturers and periods of time. Their arrangement is different than usual to maximally shorten the signal path (a similar design is used by the French company Jadis in their amplifiers). Looking from the front, instead of the usual input tubes here we see two 6Д22С rectifier diodes, dating back to the Soviet Union era, in a full wave rectifier circuit using a center tap transformer. The 6Д22С has a top cap connection for the cathode. Behind them are the great-looking directly heated triodes from Emission Labs, the EML520B-V3. They are manufactured in the Czech Republic and are also used by the Swiss company Colotube. The driver stage includes another directly heated triode, the powerful KR Audio PX25. The tube is loaded with a phase splitting interstage transformer. The input stage features another Japanese step-up transformer with switchable ratio for voltage gain. The amplifier offers three gain levels to adjust the input sensitivity to the rest of the audio system. The signal path is one of the simplest possible with absolute zero feedback.

The output transformer is also Japan-made and comes from the same manufacturer, Tamura Seisakusho Co., founded in 1924. Tamura products are very difficult to buy outside of Japan. They are used by such companies as Air Tight. The amplifier has no capacitors in the signal path. To protect against tube aging, the Spartacus uses a servo circuit that keeps the current in both output tubes constant. Microprocessor control is used to constantly monitor all the subsystems for proper operation. The hottest tube that glows bright like a light bulb is the Г-811 triode, here in the 811A version from the Chinese company Electron Tube. It is used in a constant current sourced shunt regulator.

Designing the power supply must have been a real challenge. The monoblocks are not closed from the bottom, at least not completely. Laying them on the side, you can see massive transformers in shielding cans, bigger than those used in powerful solid state amplifiers boasting the power output of several hundred watts. One of them is the power transformer and the other one is actually a massive choke, both from Plitron. They are mounted upside down to an aluminum plate that divides the interior in two. This lowers the amplifier's center of gravity and at the same time completely separates the transformers from the amplification circuits. The choke is used to reduce the noise and to dispense with large electrolytic filter capacitors. The capacitor bank is thus much smaller and comprises high quality polypropylene caps. A small СГ-13П voltage reference tube also dates from the Soviet Union era.

A special filament heating circuit includes a separate transformer winding, rectifier, filter capacitors and a voltage regulator to electronically isolate the filament from the DC source. A cooling fan visible from the rear is somewhat of a surprise, although it was not audible in operation. Its purpose is to cool down the amplifier interior and transformers cans.

And a few words about input and output connectors. The signal can be fed to either RCA or XLR input connectors. The amplifier has an unbalanced topology and the XLR input signal is first desymmetrized by a Lundahl transformer. The RCAs are the rhodium plated version of Furutech connectors, the same as in my CD player. The XLRs are, in turn, gold-plated Neutriks. The input type (RCA or XLR) is selected with a small toggle switch made of green illuminated plastic, which looks great. The speaker terminals are the Furutech FT-808, one of the best currently available terminals. I recall that when Furutech started their production I was sent two pairs to use in my speakers. And so they have been patiently waiting for their time to come…

the system’s reproduction of timbre is stunning in its realism......I knew that the THRAX gear was something special and that it belonged with the very best......Stereo Times 2013 “Most Wanted Components” award! Highly recommended!
Key Kin

SUMMARY REVIEW: I don’t do any serious listening until the gear is more or less fully burned-in, but the Thrax was different. I knew that the  Thrax gear was something special and that it belonged with the very best. I recently reviewed the legendary Ongaku and in many ways the Thrax combo is like the Ongaku in character; better yet, it produces more power to drive more demanding loudspeakers. The Spartacus drove my Consensus Engineering Conspiracy loudspeakers effortlessly with power and finesse. Voices and instruments sounded vividly alive with a remarkable high level of purity. I was in trouble; I was losing sleep staying up through the wee hours of the night listening to my favorite recordings.


My hat’s off to Rumen Artaski for creating these masterpieces and I’m sure Kondo san of Kondo-Audio Note and Shishido san of Wavac would be very proud of Rumen Artaski’s achievements. The Spartacus mono amplifiers and the Dionysos preamplifier are my Stereo Times 2013 “Most Wanted Components” award! Highly recommended!

EXTENDED REVIEW; It was at the largest and most exciting audio show in the world: Munich's High-End audio show where I first laid eyes on Thrax Audo of Bulgaria. I felt it right away, after a few seconds of listening, that the Thrax had that special something. You know what they say about first impressions? And in my case, this first impression was very long lasting. Since Munich High End, I’ve heard Thrax Audio more than a few times and each time I was quite impressed with their exceptional sound quality. It's the type that draws the listener deeply into the music's core with its captivating sense of space, detail and harmonic cues. Although the venue and the speakers were different each time, I was absolutely convinced the electronics were hugely responsible for the magic I encountered. I said to myself, “ one of these days I'm gonna review these electronics.”

I had a nice long conversation with Rumen Artarski of Thrax Audio at last year’s Munich High-End show. I mentioned how much I enjoyed his products over the years, but - of course - I requested a chance to review the Spartacus mono power amplifier and Artarski said "yes." Even better, he told me I should review the combo that features the Spartacus with their matching Dionysos line level preamplifier.

Need I mention that I was only a tad ecstatic!

Rumen Artaski, founder and chief designer of Thrax Audio, discovered his passion for audio when he was just 12 years old. He enjoys listening to European jazz, world music and, of course, Classical. His brother had an impressive rock record collection but at that time none of the records were available in Bulgaria, they were only available copied on tape. Artaski started running a very lucrative small business for his brother, transferring records (LPs and 45s) to tapes while his brother was out having fun. Artaski spent countless hours recording on all kinds of equipment and started buying and selling equipment, becoming very involved in how to make things sound better (Don’t we all). In 1990 he moved to Denmark, and enrolled in the Danish Technical University in Copenhagen to study electronics and acoustics. While in Denmark, he was buying equipment there and selling it in Bulgaria and vice versa. During this time he developed an interest in pro audio. As a true audiophile, he wanted better recordings, so he moved to London to study record engineering/producing. After graduating, he worked in a recording studio. He got hands on experience and was always tweaking the monitoring system, replacing cables and amps. He got to design and build a recording studio and, in 1998, he moved back to Bulgaria and started a number of businesses. One of them was a high-end audio shop in the center of Sofia (Bulgaria’s capital). Most of his clients were very wealthy with a genuine interest in music. He was selling Wavac and Kondo Audio Note amplifiers but the preamplifiers had no remote control. He wanted a product that sounded as good as these but would also be user friendly with a remote control. As far as he knew, none were available on the market at that time. Rumen Artaski went to the drawing board and designed his own remote controlled tube preamplifier that was good enough to pair with the very best. This led to two years of R&D in attenuators and amp topologies, power supplies and so on. And follow by another year of research and tests, involving thousands of man-hours of listening and comparisons. After showcasing the first prototype in an audio trade show, he received five orders and Thrax Audio was born.

Rumen Artaski states: "The works of Japanese tube gurus are a source of inspiration for us. Shishido San's designs with transmission triodes manifested trough Wavac Audio and Kondo San's creations at Audio Note Japan are the best examples of the Japanese vacuum tube art currently in production and the different approaches taken to achieve the same goal. Their attention to detail and manufacturing quality inspired us to try and do better. The works and concepts of another Japanese designer came closest to the direction in which we were heading. Never implemented commercially, however, the designs of Sakuma San are a tough example to follow. Directly heated triodes with inductive loads seemed to deliver the effortlessness and tonal richness we are after."

The Spartacus is a two stage shunt regulated Directly Heated-Triodes (DHT) push-pull mono power amplifier in pure class-A design. It features one of the simplest possible signal paths with absolute zero feedback (wire-vacuum-wire-vacuum-wire). To achieve exemplary performance with such a simple design, Thrax Audio uses the very best components from around the world. The Spartacus uses Directly Heated-Triodes (DHT) which delivers an extra order of magnitude and better distortion performance compared to indirectly heated ones. However, not all DHT’s are the same. Emission Labs manufactures some of the finest tubes ever made and the Spartacus utilizes a pair of Emission Labs 520B-V3 output tubes that produce a powerful 70 Watts per channel. Only the best will do, and for this design Artarski chose the highest quality Permalloy core output transformer custom made by Tamura. Rumen Artaski is a perfectionist and to cancel some of the already negligible distortion even further, a linear driver stage was implemented which supplies the two output tubes with exactly the same signal in phase for one and out of phase for the other. Using DHT was the obvious choice and a KR Audio PX25 also was used. The PX25 tube produces enough power and voltage swing to accommodate a two-fold overdrive and positive grid drive if needed. A step-up transformer was implemented to give the cleanest possible voltage gain.

The Spartacus has one of the most sophisticated and innovative power supply designs in the industry. To reduce power supply noise-noise is as we all know public enemy #1- choke input full wave 6022C rectifier tubes are utilized to practically eliminate switching noise and anything that comes before the choke, instead of the normal arrangement of diode bridge rectifier and electrolytic capacitor bank. The choke keeps the voltage on the capacitor bank quite constant and a small bank of the highest quality film capacitors is used. A power supply operates best when the load is constant. A constant current source is a device that passes the exact same amount of current no matter what happens on either end. A shunt regulator will keep a constant voltage across itself by changing its conductivity no matter what. Cleverly, it has a built in timer that counts the tubes’ working time. When tube replacement is due, after switching the unit on, the green LED will keep flashing after warm up time elapses. The Spartacus has a unique circuit design which keeps the current in both output tubes the same even as the tubes age and cannot be perfectly matched. The microprocessor constantly checks the system function to make sure the system is operating properly; if not, it shuts down to protect the tubes.

The Spartacus is milled from impressive solid plates of varying thickness 6061T651 aircraft grade certified aluminum. The chassis is meticulously thought out; the power supply section is mounted on a mid-level plate with a circuit board on top and the transformer and choke below, making the center of gravity low enough to have a signal transformer mounted on the top plate to avoid magnetic interference. There are no screws visible anywhere on the chassis and it is made in house with a CNC machine. The layout of the front panel is elegantly simple with an ON/Off switch in the middle. On the top panel there are the arsenals; a total of seven tubes two transformers, two output impedance switches for 4 and 8 Ohms to match loudspeaker impedance. There are three switch positions for input matching as with most preamplifiers; H-high gain, to be used with a preamplifier with very low output impedance capable of driving 600 Om loads and providing 2V, M-medium gain; moderate input impedance for a 4V preamplifier; and L-low gain, to be used with some 8V tube preamplifier with a higher than usual output impedance. I set the switch to M-medium gain when paired with the Dionysos. In the rear there is input for RCA and XLR and beautifully made.

The Dionysos is a single ended, single triode stage transformer coupled with a remote controlled line stage preamplifier. The line level amplifier is the foundation of any high-end audio system. It is in charge of source selecting, signal conditioning, and volume control. The line stage preamplifier has to match the output of a source to the input of the power amplifier. The output has to provide an absolute optimum driving signal to the power amplifier’s input stage; it must be low impedance, DC free, truly balanced, and isolated from noise sources and other components in the system. To create a better volume control, painstaking research and evaluation of various approaches was carried out. Rumen Artaski chose a fundamentally different and simple solution; he opted for transformers with various winding ratios instead of the usual potentiometer and resistor ladders. However, transformers have two drawbacks: they are very expensive and difficult to design. Thrax Audio states “Potentiometer and resistor ladders as sophisticated as they might be, have a fundamental flaw. They operate by dumping the unnecessary signal across a resistor. It is like driving a car with fixed engine power (signal) and adjusting the speed with the brakes (resistor).” Dionysos is a fully tubed circuit design with tube rectification using a 6C4P-EV (6u4n-B); voltage stabilization is via a SG15P (Cr15n); constant current sources feeding a shunt regulator and voltage amplification is via a single twin triode 6N6P (6H6n). All tubes are NOS Russian issue. The power supply is impeccably designed. It uses a special custom made C core transformer with a gap in the core with a symmetrical field canceling winding to prevent any saturation of the core from distorted mains or a DC component in the main. Two identical sets of windings (essentially two power transformers) are on the same core. This way all the nasty magnetic and electrostatic leaks cancel each other out, and do not influence any of the other components in the chassis. 

The Dionysos is a single box finished exquisitely utilizing ultra-high quality custom made parts throughout and featuring a meticulously crafted chassis. Like the Spartacus, it’s made of a 6061T651 aircraft grade certified aluminum machined from plates of various thickness. Ergonomics are simply beautifully thought-out. What good is advanced technology, if it’s not user friendly? Artaski anticipated all the needs of audiophiles. The Dionysos comes with a brilliantly designed full function remote control to die for. As much as I loved the sound of the Kondo Audio Note G-70 preamplifier I recently reviewed, I missed having a remote control. As a reviewer and an audiophile I believe that a remote control is an absolute must. While I’m reviewing, I constantly have to change equipment for comparison and adjust volume levels, and the LED readout makes this very convenient. Don’t get me wrong I do need the exercise but I like to get that in the gym - not while listening. Another must have feature is an phase switch; I could control phase on the Dionysos with a touch of a button on the remote control. I believe a phase switch should be mandatory on all preamplifiers. As a matter of fact at least half of all classical recordings are recorded out of phase. So, having a remote control with a phase switch makes listening much more pleasurable. You can listen both ways while sitting in your sweet spot and, at the touch of a button, you’ll hear which way sounds better. The Dionysos’s front panel is thoughtfully laid out. The large volume control knob is in the middle. The tape and mute button are to the left and input select previous, phase switch, and input select- next are on the right. There are six inputs-four pair RCA unbalanced and two pair XLR balanced and four pair outputs-two RCA unbalanced and two XLR balanced. All inputs are balanced differential unless the grounding option is engaged on the RCA inputs. There are two sets of outputs for bi-amping capability.

All of Thrax’s parts are meticulously selected after many hours of listening tests and constructed by experienced craftsmen with Swiss built quality. They really took their time to research and develop these products; it took them two years of painstaking evaluation of amplification topologies and circuit design in their lab. Rumen Artaski and his team are perfectionists who are passionate and strive for nothing but the best. Uniquely, Thrax produces only one level of performance for each model; there is no entry level or premium model, no compromises. Thrax is one of the very few companies that goes to this extreme, using only the very best custom-made quality parts available for specific design sourced from Japan, Germany, the US, Sweden, Canada and the UK. Every Thrax gear has been run for 72 hours at the factory initial break-in for reliability and sound quality testing. Cleverly, both the Spartacus and the Dinoysos have a standby mode. When in standby mode all the amplifier circuitry be turned off for minimum power consumption, leaving only a small standby circuit running.

One sunny afternoon my doorman called to let me know that I had a shipment from DHL. I was expecting a Thrax shipment and boy was I right; there were four boxes in the lobby! The Thrax gear was shipped in heavy-duty wooden crates with sensible wooden handles and as I expected, some of the tubes were shipped separately and had to be installed.  Removing the top wooden plate revealed secure foam-lined innards and the gear was nicely protected by a plastic cover. It didn’t take long to set up, all tubes for the Spartacus marked accordingly. Setting up the Thrax was straightforward; I used my reference Jorma Design Unity cables throughout the system. I did my listening to the Spartacus and the Dionysos as a set and I used ASI topline feet to assure an even more exceptional sound. 

The SOUND: The MAGIC!

Even though the Spartacus and the Dionysos arrived with only 72 hours of initial play time, they sounded superb right out of the box. I could see immediately that its sound quality, rather purity woud become instantly addictive. And, as they settled in for a couple of weeks, they continued to improve. Incredibly, the system’s reproduction of timbre is stunning in its realism - about as good as that of the Ongaku, the amplifier which in my view, is the world reference in proper replication of instrumental texture and tone. Timbres are richly rendered, with density of color and warmth that makes even the best solid-state sound a touch mechanical or artificial. Normally, I don’t do any serious listening until the gear is more or less fully burned-in, but the Thrax was different. I knew that the Thrax gear was something special and that it belonged with the very best. I recently reviewed the legendary Ongaku and in many ways the Thrax combo is like the Ongaku in character; better yet, it produces more power to drive more demanding loudspeakers. The Spartacus drove my Consensus Engineering Conspiracy loudspeakers effortlessly with power and finesse. Voices and instruments sounded vividly alive with a remarkable high level of purity. I was in trouble; I was losing sleep staying up through the wee hours of the night listening to my favorite recordings.

Listening to the Conspiracy loudspeakers driven by the Spartacus and Dionysos for past few months convinced me that these Thrax products are some of the most musical and involving electronics I’ve heard to date. They render instruments and voices with a natural and organic quality. It’s the kind of sound that as soon as the music starts playing, everything just seems right. One doesn’t need to think about anything, except for musical enjoyment. The Spartacus sounded like an SET with the power of a push-pull design. Its power output of 70W had no dynamic limitations; the system plays cleanly at respectable volumes, and it handled crescendos with delicate ease. This is an amplifier with seemingly unfettered dynamic contrast along with a powerful and full bottom-end. The Thrax didn’t sound big and bold or polite and restrained; it didn’t sound any way at all, but simply did what the music asked, no more, no less. I was in audio heaven! The Thrax electronics midrange is glorious in timbre, tone color, liquidity, and freedom from grain. The Cassandra Wilson’s vinyl recording of the New Moon Daughter (PPAN BST32861) arrived during my review. The Thrax reproduced Wilson’s husky and hypnotic voice with a touch more three-dimensionality than I remembered from this reference recording. I was startled-first by the immediacy and solidity of her image, then by the complexity of Wilson’s husky voice and coming through with a harmonic truth that surprised me. It was as if I was hearing it live for the first time. As good as my Karans are in the midrange (which is one of their great attributes) the Thrax portrayed the midrange with a greater sense of musical realism and emotional involvement.

One evening I put on the Beaux Arts Trio recording of Beethoven’s Piano Trio N0.1 in E flat Op.1 N0.1 (Philips 6725 035), dimmed the lights and sat back in my sweet spot. The Piano Trio was rendered exquisitely authentic in both weight and tonal acuity. The strings and piano were stunning, emerging from a background both blacker and more alive than I recall. The strings were a touch denser and more complex than with my reference Karans and proved enough, in fact, it took my breath away. I couldn’t stop listening to the Piano trio over and over through the Thrax electronics. One thing's certain, Thrax has an uncanny ability at digging into and thus revealing layers upon layers of subtle details.

As I have said, the Spartacus monos and the Dionysos preamplifier reproduce large-scale orchestral music with great ease. When the music demands drive and scale, Thrax simply responds on a dime. In fact, the Spartacus monos 70 watt sounded like a powerhouse driving the Conspiracy and the Kharma DB9-S's. Orchestral climaxes are reproduced with great authority and the timpani in the orchestra has a stunning impact. Listening to Dvorak’s Symphony N0.9 in E Minor, Op.95 with maestro Fritz Reiner conducting the Chicago Symphony, was an awe-inspiring experience. The Thrax had full control of my Conspiracy loudspeakers and were easily able to scale the dramatic heights of full orchestral crescendos. Play the first or the third movement and you’ll hear the ability of the Spartacus to deliver sudden dynamic shifts with convincing power. I was equally impressed with the Thrax combo’s effect on my system’s spatial performance. It was good as the Kondo’s. The Thrax electronics has an uncanny ability to portray a large sense of space and the instruments within the space, and the distance between them. The overall impression is like hearing a lifelike three-dimensional staging.

The Thrax Spartacus mono power amplifiers and Dionysos preamplifier are world-class electronics in every way this audiophile deems important. The Thrax Audio products embody an achievement in design, engineering, construction, and most of all, sonic performance. The Thrax electronics set a high benchmark for all others to be measured against. Sonically speaking, and in my system, the Thrax is good as it gets. The overall character of these electronics is pure, intimate, and emotional, leading to heightened musical expressiveness. The Thrax gear could never be qualified as inexpensive BUT, considering its performance versus some pretty stiff competition, I would qualify it as reasonably priced. I enjoyed the performance of both the Spartacus and the Dionysos but, unfortunately, I was able to only afford Dionysos at this time, so I ordered one to mark as my new reference preamplifier. Need I say more?

My hat’s off to Rumen Artaski for creating these masterpieces and I’m sure Kondo san of Kondo-Audio Note and Shishido san of Wavac would be very proud of Rumen Artaski’s achievements. The Spartacus mono amplifiers and the Dionysos preamplifier are my Stereo Times 2013 “Most Wanted Components” award! Highly recommended! 

KK: Please begin by telling us about how you first got interested in audio?    
RA:  My involvement with audio started when I was 12. We just moved back from Mexico to Bulgaria and my brother who is older than me had managed to accumulate a very nice rock record collection. At the time of the Iron Curtain none of those records were available in Bulgaria, so for people to get the records the only way was to copy them on tape. Taking advantage of that I was running a very nice small business for my brother while he was out partying. I spent countless hours recording on all kinds of equipment. Buying and selling equipment became part of the job. In the late 80’s I started looking at UK Hi-Fi magazines ( “looking" as I could not understand English). This got me started. 

KK:  Did you have formal training in audio electronics, or are you self- taught?
RA:  I’ve studied electronics and acoustics at the Danish technical university in Copenhagen and studied record engineering and producing in London.

KK:  What type of music do you listen to?
RA:  I listen to a variety of music. It’s all depends on my mood and the equipment I am listening on. I enjoy listening to European jazz, classical music, and world music but somehow rock has fallen of the list.

KK:  How would you define the high-end?
RA:  High end for me is defined by products that stand out above the rest. No compromise designs that transcend the time they were created in and our industry as a whole. Only bold designs making a statement. It is a pity that this has become so “commercial” and every product now is high end. The term has no value. But for me there is a category of products that I refer to as "State of the Art”. These are the pieces combining physical beauty, function and performance, inspiring awe and interest in non audiophiles.  Achieving this is quite a task. But some manage to do it!

KK:  What is your design philosophy?
RA:  Fix the cause of the problem not the artifacts.

KK:  Tell us about the company; do you do all the designing or is there a design team?
RA:  Thrax has a design team of 5 engineers and myself. Each specializing in a particular field we have one engineer specialized in tube circuits and has 40years experience! ( we refer him as “vacuum head”), others specialize in microprocessors, CAD/CAM and so on. The vast experience I have in multiple fields of installations and gear lets me define the tasks very concretely. I would come up with the concept and topology and they make it work.

KK:  Analog or digital - do you have preference?
RA:  On the Analog vs Digital I could say that people are very biased one way or the other but the truth is elsewhere. The value of Vinyl is in the countless priceless records out there that will never be available on any other medium or if available will be a mediocre copy. As a format vinyl has many flaws and it is a miracle the quality of reproduction we can get out of it. Properly done digital is also very good these days. I would say even better than anything else but most of the recordings done in the 80’s and 90’s suffer from deficiencies in the convertors used to record them. Let’s be honest, even today most studios use cheap A to D converters and preamplifiers. Few can afford a proper monitoring system let alone the full signal path (I know I have installed quite a few). Possibly the best sounding replay is that of master tapes on a “modernized” tape deck if the tape is of a recording done by organizations with limitless budgets at the time, like the BBC or some German state organizations.

KK:  What do you see for the future of high-end audio in general?
RA:  I see high-end audio being split into two tiers, luxury ego booster products selling exclusivity more than anything else and high performance but usable audio products for those that spend their money on music. Plenty of companies trying to do both will fail in misery.

KK:  My last question is: What does the future hold for Thrax Audio?
RA:  Thrax continues its R&D and we have improvements on the current line and at some stage we will introduce replacements for the current products, but we have no plan at the moment for other products in the line. We cover both sources digital and analog, we have a preamplifier and two power amps Spartacus and for “tubephobics,” The Heros hybrids.

KK: Thank You for your time.

THE THRAX ORPHEUS PHONO STAGE MIGHT BE EXPENSIVE, BUT CHRIS BRYANT DISCOVERS THAT IT SETS A NEW BENCHMARK FOR VINYL REPLAY
Chris Bryant
REVIEW SUMMARY: At the price point I anticipated exceptional performance, but ultimately was almost overwhelmed by the Orpheus’ prodigious sonic capabilities. There is nothing wholly revolutionary about this amplifier, as it employs existing, accessible technologies. Yet through careful research the designers have crafted and assembled something quite exceptional. Its stunning sound quality encouraged me to abandon digital replay entirely while it remained in my possession. The best vinyl reproduction requires quite extreme esoteric design and exotic components, a path the Orpheus follows faithfully to achieve the amazingly high score
of 225. The best phono stage I have so far encountered has to be at or very near the top of my very short list of truly great products, and may be highly recommended. 
EXTENDED REVIEW: The THRAX ORPHEUS phono stage is a comprehensive, mains powered, standalone unit with both balanced and unbalanced input and output facilities. Like the Thrax Dionysos pre-amplifier (HIFICRITIC Vol6 No3) the casework is beautiful bead-blasted silky-finished aluminium with a stylish, deeply sculpted thick front panel. The side, back, top and bottom panels are also substantial. Five buttons in the depressed centre cover on/off, mute, phase, and input selection, confirmed by associated LEDs.

 The recessed back panel has two pairs of single ended RCA/phono sockets and one pair of XLR balanced connectors. I found the print here almost illegible unless the lighting and view angle is just so. Each input pair has three switches to select MM/MC, high or low gain, and choice of grounding option. Other switches select between the XLR and RCA outputs, and ground lift. The RCA inputs are wired in balanced differential mode unless the grounded option is chosen. Beneficially, both ground and live input connections are switched to avoid any external ground noise from an unused input. if more than one is in use. The usual IEC mains input is fitted, switched and filtered.

 What makes this product cost so much?

 Admittedly it’s very well made with a beautifully finished case, but the components inside are what really count. First, it’s designed to cater for both MC and MM cartridges, and the extra MC gain is provided by a top-of-the-line Lundahl transformer with an amorphous cobalt core. This is easily switched into circuit, and input impedance adjusts automatically to the cartridge used.

 Input stage amplification uses a NOS Siemens D3A low noise pentode wired in triode configuration. This is followed by a passive RIAA filter executed using special coils wound by Sowter using Cardas high purity wire, and Jupiter Beeswax impregnated paper capacitors. A low noise Russian triode then drives a top quality Hashimoto output transformer. To obtain accurate RIAA equalisation, very precise inductor values are required, alongside low hysteresis cores. Few manufacturers use such a configuration because producing a consistent product is very expensive.  The power supply also uses costly parts, starting with an air-gapped C-core transformer. This helps avoid core saturation caused by DC on the mains, and symmetric windings are arranged to cancel any stray electromagnetic fields. Valve rectification is employed, but instead of the normal electrolytic smoothing capacitors, a massive (17H) Lundahl choke works alongside a much smaller, high quality, long life, paper-in-oil capacitors. This configuration is claimed to block rectifier switching noise most effectively. The solid state regulators use FET shunt designs made using discrete components. Most of the active circuitry uses PCBs with various component technologies from surface-mount to hand-wired chassis-mounted capacitors. Build quality resembles precision instrumentation.

Lab report

The standard level 1kHz distortion measures -64dB on MM and -50dB on the MC input, which is satisfactory for the technology used. These figures increase to -42/-34dB at 20Hz and -46/-37dB at 20kHz MM/MC respectively, which are a little higher than we would like. Intermodulation at -30dB for both inputs is also quite high, but the primary 1kHz artefact of the 19/20kHz tone pair is not accompanied by a spread of harmonics, which is a good sign.

 Channel separation is a constant 42dB from 20Hz-20kHz on MC; on MM it is a very respectable 72dB at 20Hz reducing to a still reasonable 56dB at 20kHz. Sensitivity is sensibly set at 5mV for MM and 0.5mV for MC. The signal-to-noise ratio is a very good -80dBA for MM and a still good -72dBA for MC. Driven from a 20ohms source impedance, the frequency response is flat through the midrange but falls slowly below 200Hz to -1dB at 100Hz and -3.5dB at 20Hz. Although the treble is quite flat all the way to 20kHz, I would like to have seen a flatter response in the lower octaves, and the sound may consequently be a little dry.

Sound Quality

 The Orpheus was left to warm up for 24 hours before I lowered the stylus onto Bruch’s Violin Concerto No1. I was immediately amazed. This 1968 disc is nothing special, but I was transfixed by the power and realism produced – it had so much more body, more focus and precision than anything I’d previously heard from this recording. Violins really did sound more ‘live’, and far closer to having someone playing in the room. This was a stunning revelation of tonal colour and vibrancy, in comparison with the ‘digital greyness’ of so many modern hi-fi products.

 On piano it sounds rich and full, flowing well with great perspectives, balance, and staging. The midrange is very lively and dynamic, tonally very pure, and reproduces stringed instruments with a more of a sense of ‘being there’ than I’ve experienced from any consumer replay medium previously. The treble is also excellent: devoid of grain, with great detail, precise focus and an airy realism I’ve rarely heard from a hi-fi system before. Image stability is also exceptional with finely etched focus within the expansive sound stage. It’s very analytical and transparent, had really good width and depth, creating an interesting illusion of live performance.

 Choral music also works so well that the Orpheus creates a great sense of the space around the performers, as well as reproducing the purity and beauty of voices. The timing ability is also excellent, so excellent in fact that when I went back to the fairly decent digital set up I had been happily listening to previously, I thought it must be broken because it sounded so painfully bland.

 The Orpheus has excellent bass: solid and forceful with fine tactility and resolution. It’s able to separate out complex multiple strands while translating awkward pitch changes admirably. It may not quite have the low end bang and very low bass extension of some of the best solid state competition, but that is about all there is on the downside.

 Irrespective of the music played, it had the ability to extract fresh sounds and bring my attention to new phrasing and a fresh sense of rhythm pulled from well known pieces. It is also great on rock and pop material, often managing to reveal fresh information from 50 year old pop grooves. It is simply a revelation.

 A top quality mains cable is mandatory for a product of this quality, and I did find I could easily organise the sound by changing this lead. Therefore, despite its clever transformer and power supply, it’s still not quite immune from the vagaries of the mains supply. Finally, the feet: the attached hard plastic feet proved quite good, but I found further improvements in structure, focus and staging using three Synergistic Research MIGs on an Isoblue rack.

Conclusions

 At the price point I anticipated exceptional performance, but ultimately was almost overwhelmed by the Orpheus’ prodigious sonic capabilities. There is nothing wholly revolutionary about this amplifier, as it employs existing, accessible technologies. Yet through careful research the designers have crafted and assembled something quite exceptional. Its stunning sound quality encouraged me to abandon digital replay entirely while it remained in my possession. The best vinyl reproduction requires quite extreme esoteric design and exotic components, a path the Orpheus follows faithfully to achieve the amazingly high score

of 225. The best phono stage I have so far encountered has to be at or very near the top of my very short list of truly great products, and may be highly recommended. 
.......Chris Bryant

Review System
Bully Sound BSC100 and D’Agostino Momentum power amps; Audio Research REF5 SE and Townshend Allegri control units; Linn LP12/ Radikal/Keel, Naim ARO, Ortofon Anna, Rondo Blue, Koetsu Urushi Vermilion vinyl sources; Wilson Audio Sophia

3, Supravox 215-2000 EXC speakers; van den Hul D501S phono interconnect and Transparent XLmm2 cables. 
The quality of the sound features is so high that this Thrax system could be exhibited in the Museum of Sound as a perfect example of a high class, sophisticated piece of art.
Wojciech Pacuła,

REVIEW SUMMARY: I have defined a potential owner of this system at the very beginning of this text. Thrax does not like compressed  signal, as it decreases scale of the sound, and creates an impression of the whole sound coming from area in axis in front of the listener. It does happen even with well produced recordings like Porcupine Tree's  The Incident. The whole structure of the music seems to fall apart, there is chaos instead. Thrax doesn't forgive that. Classic recordings with a lot of air BEHIND performers (and above them) tend to be re-interpreted as the foreground will be shown closer to us and there will be less of the air in a distance. Also phantom images won't have a real depth.

But if one listens to the music I mentioned before sound will be amazingly palpable. It will fullfill expectations of those who search for a rich, clear and close sound rather than presented in a distance. Depth of the sound in outstanding and I am sure that one could credit low-distortion drivers and resonance-resistant (coloration free) cabinets for that. Make and finish is top class. Also elements used for both products are of top quality. Rumen Atarski developed a system he can be proud of.

EXTENDED REVIEW: To be honest I can't remember how it started. In my own review of Dionysos preamplifier for January 2011 I wrote that I'd firstly learned about existence of Thrax Audio one year earlier during High End 2010 Show in Munich. But now I really can't remember any details. It seems though that I somehow knew already then that it was a brand worth interest. I was the first, or at least one of the first people who reviewed Rumen Todorov Atarski's product (outside his homeland, Bulgaria). For a few years it was also the only review in Poland, as it took few years to find a proper distributor in our country.

Since the foundation of this company its core product has always been a linestage—as if Rumen thought that it was a key element of the system (I always thought exactly the same thing) – that is quite a unique approach in audio world. For the first few years all other products were presented always as prototypes. As you can read below, in fact he started his audio adventure by designing loudspeakers. It took him many years before the first model, Lyra, was finally released in 2014. Just like his preamplifier and power amplifiers also speakers are quite a unique design.

Last month you could read in HighFidelity what a CEO of YG Acoustics, Mr Yoav Geva, had to say about his loudspeakers. Not only do they use many interesting solutions for the drivers and crossovers, but also cabinets of their speakers are quite particular, being a key factor in achieving a final sound. These cabinets are made of aluminium slabs using vibration-free pressurised assembly, creating sort of monolith design, that reminds me of products of another American company Magico.

Not more then 5-6 years ago using any other material for speakers' cabinets than wood (in one of its forms or the other) was thought to be eccentric (at best), possibly harmless but having nothing to do with "true" audio. These eccentricities included materials like: glass, concrete and aluminium. Today, after the audio world recognized the amazing Crystal Cable speakers (glass) and both above mentioned manufacturers of aluminium speakers, the general view on what is and what is not the "right" material for speaker's cabinet has changed significantly.

Thrax Audio Ltd., a manufacturer of Thrax products, decided to use most rigid, vibration-free enclosures for their products. Based on the experience of other manufacturers, they knew how to do it—it "only" required them to buy crazy expensive CNC machines. So they did. It didn't take long before they had such an advanced machinery and such an experience with using them that some renown European high-end  manufacturers started to commission enclosure production to the Bulgarian company.

A casing of the new power amplifier, Teres, looks like it was carved of solid aluminium block—the fit and finish is that good. Actually it was made of aluminium plates put precisely together, with outer surfaces of side panels  milled in such a way that they look like radiators.

This amp is getting really hot under stress as the current mode uses a pair of single transistors per phase. It is a unique design as there are only two gain stages in a cascode: a single penthode C3g in the input stage and JFET followers in the output. C3g is an octal tube with metal body. Input and output stages are coupled with a single transformer. There is no negative feedback loop.

When it comes to electronics aluminium casings are very common, even such advanced ones as Thrax's. But aluminium cabinets for speakers are still quite rare. Lyra speakers are the newest addition to Thrax portfolio despite the fact, that  Rumen Atarski's first audio project ever was speakers.

It is a two-way, three-driver design, with drivers in D’Appolito array. The concept is quite unique because of extraordinary rigidness of the cabinet, very special, aluminium bass-reflex port design, and very special crossover. The latter sports a huge capacitor for tweeter and that's it! Speakers and amplifiers use a high quality, user-friendly Furutech speaker binding posts.

A few simple words…
RUMEN ATARSKI - Thrax Audio | CEO

The story of Teres.  As you know Spartacus is our statement amplifier, 2 gain stages with Class A push pull output stage. Many people were scared by the exposed tubes and all were requesting a bit more power. So I started working on a circuit that will have a tube controlling a power MOSFET that can replace the output tubes in the Spartacus. Solid state and inductive loads don’t go well tighter and many devices let their grey smoke out. Fortunately for us new devices were introduced to the market that could withstand the high voltages and power required. This gave birth to a unique cascode system for the output. It is still operated at high voltage but not nearly as high as on the tubes. The output transformer used to load this cascode made it sound and behave as a tube amplifier and simplifying the input, as to be essentially a single stage device. So Heros was born.

A year later all our dealers started asking for more power and bigger amplifier with the same character. There was no commercially available output transformer of sufficient quality for power above 200W, so the only option was transformer less output stage. This automatically prevented the use of Heros driving system, so I went back to the drawing board. We resorted to the topology of Spartacus again and implemented it in Teres. we use an input tube for voltage gain and a transformer for phase splitting (same as in Spartacus), but here we replace the standard push pull output with 2 totally independent single ended followers based on a scaled version of our cascode. Running them out of phase to each other and sharing the load, forming a bridge that is unbalanced by the phase splitting transformer signal in order to be re-balanced trough the load with a mirror image of the same signal. The output stage has no character of it’s own, so the sonic color of the the tube stage is the overall character of the amplifier.

Regarding Lyra. The development started around a driver developed by BMS. It uses a ring diaphragm. It was patented more than 15 years ago. During the research for wide bandwidth horns at Spherovox new profiles with different directivity properties where developed. We just adapted one of the designs for high end audio.

It uses a custom "short" version of the driver and the special horn to cover the 1.5k-20k range with an outrageous sensitivity of 112db/W. We use a combination of the horn loading and the High Pass filter to tailor the response of the tweeter while severely attenuating it to mach the mid/bass unites. There is no stress for this driver at ANY level. It practically has lower intermodulation distortion than the amps.!

The 6.5" drivers are used only bellow the 1.5kHz crossover. This prevents them from exiting the breakup modes of the magnesium diaphragms. In order to get the perfect time/phase alignment the front panel of the speaker is carved from solid accommodating for the relative positions of the drivers. Geometry is optimised for listening distance of 3.5m. The solid aluminium prevents any vibrations in the enclosure and specially the front.

THRAX AUDIO in High Fidelity
• TEST: Thrax Audio MAXIMINUS + DIONYSOS + SPARTACUS –D/A Converter + preamplifier + power amplifier, see HERE
• INTERVIEW: Rumen Atarski | Thrax Audio – CEO, see HERE
• TEST: Thrax Audio DIONYSOS - linestage, see HERE

Recording used for the test (a selection):
• Abraxas, 99, Metal Mind Records MMP CD 0102, CD (1999).
• Abraxas, 99, Metal Mind Records/Art Muza JK2011CD07, gold-CD (1999/2011).
• Aquavoice, Nocturne, Zoharum Release ZOHAR 077-2, CD (2014).
• Bob Dylan, Oh Mercy, Columbia/Sony Music Labels Inc. SICP-30579, Blu-Spec CD2 (1989/2014).
• Helen Merrill, Helen Merrill with Clifford Brown. Singles box, EmArcy/Universal Music LLC (Japan) UCCM-9336/8, "Limited Edition" 3 x SHM-CD (1955/2014).
• J.S. Bach, English Suites 1, 3 & 5, perf. Piotr Anderszewski, Warner Classics/Warner Music Japan WPCS -12882, CD (2014).
• Leonard Cohen, Popular Problems, Sony Music Labels SICP-4329, CD (2014);
• Leszek Kułakowski Ensemble, Looking Ahead, ForTune 0043, "No 031", CD (2014).
• Ludwig van Beethoven, Sonatas op. 109, 110 and 111, piano: Evgeni Korolov, Tacet 208, "The Koroliov Series Vol. XVI", CD (2014).
• Pet Shop Boys, PopArt: Pet Shop Boys – The Hits , Parlophone/Toshiba-EMI TOCP-66252-54, 3 x CCD (2003).
 Porcupine Tree, The Incident, Roadrunner Records/WHD Entertainment IECP-10198, 2 x HiQualityCD (2009).
• Queen, Queen Forever, Virgin/Universal Music LLC (Japan) UICY-15347/8, 2 x SHM-CD (2014).
• Sting, All This Time, A&M Records 212354-2, SP CD (1991).
• Voice Factory, Voice Factory Sings Chopin a Capella, Voice Factory, CD (2014).
Zapach psiej sierści, soundtrack, music Włodzimierz Nahorny, GAD Records GAD CD 019, "Limited Edition 500 Copies", CD (2014);

Whatever will I write later, whatever assessment will I pass I would like to send a strong signal already now to all electronic music fans, to those who like close, palpable presentation, and to those who expect not a huge space far behind speakers, but a close sphere built around listener sitting in its center: all of you can can search no further. If you can afford this system just buy it and keep it for ever.

It is a system of a very strong sonic character. What it offered might not have been exactly my cup of tea, but it did not matter at all. This time I didn't mind at all to fall for something offering quite different qualities from those I usually search for. The quality of the above mentioned sound features is so high that this Thrax system could be exhibited in the Museum of Sound as a perfect example of a high class, sophisticated piece of art.

Lyra speakers together with Teres amplifiers build a warm, rich sound that is also amazingly vibrant. This is obvious no matter what recording one plays, no matter what music genre. The precision this system forms the sound with, makes you wonder about choices of other  audio designers, in particular those who create loudspeakers. If you use Thrax amps with most of speakers using paper drivers you will realize that they tend  to mask problems generated by other elements of the system. Lyra show us that paper, which under certain circumstances sounds warm and soft, is used to mask a roughness, harshness of the sound.

I think that these solid, metal cabinets of Lyra speakers work in similar way. If one uses a low distortion, precise drivers in such z high class cabinets they will start to act as sort of magnifying glass providing listener with information about any problems originating from any element of the system. To use that to one's advantage one needs a very well designed crossover and a high class system driving these speakers.

Not all manufacturers utilizing paper or plastic cone drivers for their loudspeakers with wooden cabinets do that because they can't do any better. Anybody who knows JBL, Spendor or Harbeth speakers can vouch for that – these "antique" technologies and materials, properly used, deliver outstanding results. But more often then not using them will result in less favorable sonic results.

Thrax chose a different, I think most difficult way. There are only very few companies that took the same path and succeeded—YG Acoustics and Magico are best examples. Thrax system produces similar results. Anybody who claims that transistors produce a "cold" sound, and metal cabinets and drivers deliver a "dry" sound, has really no knowledge of the audio industry and audio products. If he based his opinion on particular products, these particular products must have been faulty and not the technology or solutions. The latter offer particular benefits, have some flaws of their own, but are surely not a bad choice—only a particular application might be wrong.

Was it because of elimination of cabinets resonances, or usage of amazingly linear C3g tube, (whose cousin,  C3m, I knew from some other top products), or most likely due to many elements working together, these speakers create a dense sphere made of air, sounds, details that surrounds listener. If only recording we play allows that. Because when we play a recording that was made in such a way, that we perceive sound as coming from far behind speakers, than Thrax allows the sound out of this sphere. That's how the latest Piotr  Anderszewski CD recorded in Warsaw with J.S. Bach's English suites 1, 3&5 from Warner Classics, sounds like. I have a version of this recording released in Japan. This type of production focuses on a soloist presented quite close to the listener, but it does not create a "wow" effect as there are not so many other sounds coming from sides or from behind us. It is not a very lively sound. Thrax system did not try to "light the presentation up", didn't try to deliver the very essence of the music, it simply conveyed the recording in a way it had been made proving why other recordings, like Anderszewski from Carnegie Hall sounded better.

Quite a different result we shall achieve with recordings where some spatial spatial effect were used, were out of phase sounds were used to create an impression of sound coming even from behind listener. These recordings create an impression of surround—multi-channel sound. There are quite a lot of such recordings. The best ones were prepared using the Q-Sound system, like, for example: Roger Waters' Amused to Deathor Sting's Soul Cages.

There are also some Polish interesting recordings of that kind. I really like the group Abraxas so I often listen to their album 99. They are representatives of so called art-rock (progressive rock), and this particular album was recorded in 1999 by Jacek Gawłowski, who received a Grammy Award in 2014 for Włodek Pawlik's Night in Calisia. For that album he was involved as a producer and a mastering engineer. He was also involved in a project of re-issue of first four Czesław Niemen's albums.

Anyway, on 99 between tunes there are additional pieces of music that include very special spatial effects. The reviewed system recreated those spatial effects in an amazing way. I have not heard any multi-channel system (regardless its price level) that came even close to Thrax's performance. Bulgarian system delivered extremely rich sound, surrounding me continuously, without and division for front and back sounds.

This system will present in a very interesting way also some recordings that are usually not "liked" by most audio systems. I mean those recorded with microphones placed very closely to instruments, mixed from multiple tracks, usually as multi-mono—this actually means 99% of music material that's been produced for many years now. For example—the latest Leonard Cohen's album, Popular Problems. System delivers the foreground very close to the listener. It is a large scale, rich sound so it creates an impression that we sit in the first row, just in front of the stage. This manner of presentation was even clearer when I listened to Voice Factory album with  Chopin's music, sang (a Capella) by NOVI Singers (album comes from GAD Records). Microphones were placed so closely to singers that it created an impression of a very small distance between listener and singers standing in my room. The reviewed system provided also information about quite aw realization, not so perfect voiced were taken by microphones placed very closely.

Tonal balance is set quite low. Speakers deliver very clear, rich sound, with bass going really, really deep. The lowest octave is "indicated" mostly with higher harmonics, but these are delivered in almost perfect way which creates an impression that we listen to much larger speakers and the we can really hear even lowest notes.

Treble seems warm but also very vibrant. Cymbals sound seems bit darker than in reality, even slightly darker than delivered by my Harbeth speakers. But there is no "rounding" or "softening" of leading edge. It's a rare combination—sound are not "lightened up", and yet the decay phase is rich and long enough.

The key element of this presentation is midrange though. Many good things can be said about deep bass and rich treble, but they both seem to only complement midrange that is amazingly rich and complete. Images are not precisely depicted as they are presented very close to the listener. Their energy is extraordinary though. Sound is quite energetic despite the fact it is also quite warm.

This particular set of features should satisfy all fans of music I mentioned before, plus fans of electronic music. I believe that if Tadeusz Łuczejko, whom I met a few days earlier (a musician, member of Aquavoice, an organizer of Gorlice Ambient festival could have listened to his album Nocturne on Thrax system, who would have loved it. The sound was very essential, rich, mature but also very pure.

Summary

I have defined a potential owner of this system at the very beginning of this text. Thrax does not like compressed  signal, as it decreases scale of the sound, and creates an impression of the whole sound coming from area in axis in front of the listener. It does happen even with well produced recordings like Porcupine Tree's  The Incident. The whole structure of the music seems to fall apart, there is chaos instead. Thrax doesn't forgive that. Classic recordings with a lot of air BEHIND performers (and above them) tend to be re-interpreted as the foreground will be shown closer to us and there will be less of the air in a distance. Also phantom images won't have a real depth.

But if one listens to the music I mentioned before sound will be amazingly palpable. It will fullfill expectations of those who search for a rich, clear and close sound rather than presented in a distance. Depth of the sound in outstanding and I am sure that one could credit low-distortion drivers and resonance-resistant (coloration free) cabinets for that. Make and finish is top class. Also elements used for both products are of top quality. Rumen Atarski developed a system he can be proud of.

DESIGN

TERES
Teres is a monaural power amplifier. It is a hybrid design, with C3g pentode (in triode mode) in the input stage and transistors in the output stage. According to Rumen Atarski there are only two (!) gain stages. What's more, input stage (tubes) are loaded with transformer—it is the large cube in the middle of the casing. Behind it there is only a second cascode gain stage based on JFETs and MOSFETs.

Developing a device based on such a simple concept requires a lot of time and effort. At least if sound quality and good measurable parameters is what we want to achieve. Teres is uniquely simply design. Input section is placed on a PCB bolted to the back panel of the device. It includes almost complete power supply section for C3g. Power transistors are placed inside two small aluminum boxes. These have a shape of a section of cylinder. They are bolted to the sides of the device and they produce most of the heat one can easily feel after turning Teres on.

In the middle there is a large toroidal transformer and two large smoothing capacitors. On top of them designer put a small board with SiC Shottky diodes. This material called carborundum is used in many top designs, one of them being SPEC Corporation Designer Audio REQ-S1 EX phonostage.

Amplifier sports RCA and XLR inputs, but the device works in an unbalanced mode. Signal is balanced in coupling transformer. The whole circuit is controlled by a microprocessor that sits on separate board and sports a separate power supply. Teres works without negative feedback.

LYRA
Lyra is a two-way, three-driver monitor. It sports a vented enclosure that is made of aluminium plates screwed together. Also bass-reflex port is made of aluminium. A mineral wool was used for internal damping.

Drivers are screwed to the front baffle from inside, so the screws are not visible. A solid aluminium carved front panel incorporates a horn with specific directivity and frequency response. Its shape was developed by a company Spherovox. A ring diaphragm compression driver was custom built by German company BMS.

Two mid-lowrange magnesium diaphragm 6.5'' woofers work together. These look like top line SEAS drivers. They sport a magnesium membrane and copper phase plugs. They work below 1,5 kHz.

Loudspeaker sport a puristic crossover of  the 1st order, built of the most expensive elements including Mundorf silver capacitors and a huge coil. Even speaker posts were chosen to achieve the best sound quality—these are the same posts that are used in amplifier—Furutech FT-816.

The only thing these speakers miss are matching stands. For now any solid 70cm stands should be fine, but since these are high-end speakers they will show any problem with accompanying system including low quality stands.

...........Wojciech Pacuła,

The Thrax Audio quest is quintessential. True refinement of actual/factual high performance outcome. Real expertise is shown when the implementation of the solid state and tube technologies become subordinate to the one and only master. The music!T

REVIEW SUMMARY: Orpheus explore the analog universe of vinyl in its own complex, unique and highly involving way. This phono preamplifier stand out a lot among the highly acclaimed products offering from across the ocean and from the land of the rising sun. .......and this is where Thrax Audio Orpheus phono preamplifier shines with the torch of the natural light. Nor saturated melahonic light. Nor modern led overly exposed lighting. What happens with the Thrax Orpheus is a palpable rendition of the ear catching sublime reconstruction of the anchor points. This complexity of focus points drives phono reproduction into the 21st century and evoke large emotional burst expected with the esoteric high-end audio equipment. 

EXTENDED REVIEW: There are few high-end audio companies, that are operating on the level, that really works and stand out in my book of high-end audio dealings these days. Among these is definitely Thrax Audio from Bulgaria. I’ve had some insights into their business from the past experiences with the brand products, but my recent visit to the factory changed a lot. Seeing the dedication, R & D and most importantly the enthusiasm that goes into their product was an eye opener. 

In past few years I’ve had opportunity to test and review their Dionysos preamplifier and Heros monoblocks. I was both intrigued and inspired not only with the topologies, building quality, but most importantly with the sound of the devices. Dionysos received Mono & Stereo prestige upper echelon award and it was rated among the best preamplifiers on the market. Actually its one of the best (tube) preamplifiers on the market. If any other company would produce such preamp the price would go rocket high. But Rumen Artarski choose really competitive and down to earth pricing. Dionysos is actually one of the few real bargains when it comes to the performance/price ratio. 

In designing their products Rumen take no prisoners. He always want to create something different, musical and stand out. His research involved the actual acquisition of wide array of most acclaimed products including legendary Audio Note Kondo products. He didn’t rest until the sound reach the level, that not only matched but succeed the highest plane. 

At my factory visit I’ve witnessed quite mind blowing things. Call me thrilled! Thrax Audio possess utterly impressive stock of most exotic parts. From esoteric Japanese chockes, output transformers, tubes (Western Electric etc.) and stunning number of prototypes that led to development of their final products. Many of the the products being developed along their research are still in the loop and waiting for further execution and will most probably being finalized into the end product. I do hope so! I’ve had a chance to listen to few and they all represent the different takes on the ultimate high-end audio reproduction from the different angles. More will be revealed in due time, but I can assure you that these are all special and really hope that many of them see the light of the day. 

One of the biggest advantages of Thrax Audio is the slow and profoundly in depth pace of the development. They really do their homework and are researching deeply into the subject matter. Rumen showed me different schematics, documentation and measuring equipment being used during the researching. I’ve been around the world at even many of the big brands fails short compared to the completeness and complexity of the Thrax Audio operations. They can produce everything from ground up in house. as their premises embraced design labs, research facility, their own CNC machinery, bead blasting machine, anodizing chamber, laser engraving etc. In that way they can project and explore all the smallest nuances of the development phases completely independently. That makes them very unique and this is a company to watch! Their direction is firm and bold…

Lurking closer into the way Thrax Audio team work reveals a profound take on the technologies. Rumen mindset is a complex endeavor of constant contemplation, refinement and pushing the boundaries way over the standard norms. I’m always thrilled and highly respectful to the high end audio designers and companies  paying the respect to the historical technical findings and the industry heritage. To many high-end companies these days claims their uniqueness and ego maniacally declares their superiority and ground braking solution, skipping the decades if not hundreds of years of building up of the industry as it is today.  For such thinking people must use horse blinders as the Vienna lipizzaner horses does. This kind of thinking goes hand in hand with the analogy of the people who see themselves being materialized into this world without actual father and mother. As they would just come to the existence without any roots and history. Interesting phenomena… This is utter nonsense and a clear indication of bullshit marketing.

Answering emails, phone calls, private messages falls into my daily routine and more and more people are doing their homework dead seriously when it comes to their beloved hobby. Audiophiles and music lover started to research into the companies and their dealings. If they’re reaching for something that cost as much as a car, small apartment of complete student funds, they want to feel safe with their investment. To lay it down realistically.  Its not all about the funds. People want to known the actual technical solutions and implementations of audio technology. The same thing they demand to know when they’re purchasing the expensive analog timepieces or the cars. 

Along that, many of contemporary buyers are used to the dealings from other luxury industries and their demands are not easy to be met. High-end audio became luxury industry like it or not. As such it the business operation and the way customers are treated is of no second plan. Still, each high-end audio company will follow their own distinctive vision and in both short and long terms results will follow. What I can assure you is the sophistication and high expectations of current consumers. I work a lot with Asia and have many friends and followers there. Market in Asia changed a lot past few years and most of the older high-end audio brands didn’t (or don’t want to) figure that out. Many of the buyers felt offended by the dealings of the certain companies they bought (highly expensive) products from. A lot of them will never in life purchase again the upper class priced products only because of the way the companies treated them and of directions of their behavior took. I won’t lay down the names, but I trust my readers can decode in my writing intelligible nature. I trust in human perception of common sense and see the broad present audience as highly intelligent.

This all brings me to the product under my scope. This time its Thrax Audio Orpheus phono preamplifier. You could say I’m the analog fan and vinyl enthusiast for more then three decades now. My quest for vinyl satisfying experience led me through numerous quests and explorations. This accounts for wide array of the differently priced devices. From entry level, mid prices, upper high-end and exotic ones. I will be honest and share my findings directly as usually. As a fact, there are not many great sounding and performing phono preamplifiers. Getting right the audio signal form smallest scale mV output of the cartridge is a complex art of itself. For quite many of audio designers and manufactures this complex electric mechanics seems too easy. Designing a great sounding phono preamplifier is no simple task The reality is shockingly solbering state of the affairs. Most phono preamps just don’t cut it. As a rule most phono line stages brings the noise down. In one strike they kitten themselves with the galore of the technical data. The real problem is much more deep. While doing this they kill the music! Intricate nature of subtle, highly sensitive signal coming from the phono cartridge is uber prone to anything in the signal path. Every element or the execution of circuit will affect the sound outcome profoundly. Everything and anything is crucial with such miniature scale transfer of the energy. 

The true expertise and art reveal itself when all; low noise floor, transparency and musicality goes hand in hand. Here the vast phono preamplifiers offerings are narrowed down to very a very few real contenders when it comes to state of the art musical reproduction.

As with other Thrax Audio products the Orpheus is no happy accident. Its a labour of Rumens love and striving for the perfection in conveying music as it is. He is also an avid  analog fan and it shows in grand way. Going beyond mediocre and trying to find the solutions that will lay down the path for the unrestrained musical reproduction is his clear musical sentinel role.

Orpheus explore the analog universe of vinyl in its own complex, unique and highly involving way. This phono preamplifier stand out a lot among the highly acclaimed products offering from across the ocean and from the land of the rising sun. 

Again, with Orpheus Rumen pushed things to go beyond typical technological solutions and the result surpasses the typical “tubey” sound being as a rule connected with the valve based phono equipment. When things done right, tubes are only the carriers of the sound and do not act as an colorful saturating devices. They can be as transparent as solid state devices when implemented right. This is not easy achievable, yet its possible. Thrax Audio again showed and laydown the path of the future where the technology by itself is not a matter of pinpointing anything. The Thrax Audio quest is quintessential. True refinement of actual/factual high performance outcome. Real expertise is shown when the implementation of the solid state and tube technologies become subordinate to the one and only master. The music! It is about the execution of pure musical flow, spatiality and rendition on the upper plane. 

I’m not talking about sweet intoxication of the Van Gogh or Akira Kurosawa artistic palette. I’m referring to the true via medium, that can transparently convey the music close to the source and with the technical solutions that are possible to explore with the materials, technology and know how of today. 

And this is where Thrax Audio Orpheus phono preamplifier shines with the torch of the natural light. Nor saturated melahonic light. Nor modern led overly exposed lighting. What happens with the Thrax Orpheus is a palpable rendition of the ear catching sublime reconstruction of the anchor points. This complexity of focus points drives phono reproduction into the 21st century and evoke large emotional burst expected with the esoteric high-end audio equipment. 

More to come…....

I have not heard any system (regardless its price level) that came even close to Thrax's performance. Bulgarian system delivered extremely rich sound, surrounding me continuously, without and division
Wojciech Pacuła (translation by Marek Dyba)

REVIEW SUMMARY:....sound will be amazingly palpable. It will fulfill expectations of those who search for a rich, clear and close sound rather than presented in a distance. Depth of the sound in outstanding and I am sure that one could credit low-distortion drivers and resonance-resistant (coloration free) cabinets for that. Make and finish is top class. Also elements used for both products are of top quality. Rumen Atarski developed a system he can be proud of.

EXTENDED REVIEW: Thrax Audio - TERES Power amplifier + LYRA loudspeakers
To be honest I can't remember how it started. In my own review of Dionysos preamplifier for January 2011 I wrote that I'd firstly learned about existence of Thrax Audio one year earlier during High End 2010 Show in Munich. But now I really can't remember any details. It seems though that I somehow knew already then that it was a brand worth interest. I was the first, or at least one of the first people who reviewed Rumen Todorov Atarski's product (outside his homeland, Bulgaria). For a few years it was also the only review in Poland, as it took few years to find a proper distributor in our country.

since the foundation of this company its core product has always been a linestage—as if Rumen thought that it was a key element of the system (I always thought exactly the same thing) – that is quite a unique approach in audio world. For the first few years all other products were presented always as prototypes. As you can read below, in fact he started his audio adventure by designing loudspeakers. It took him many years before the first model, Lyra, was finally released in 2014. Just like his preamplifier and power amplifiers also speakers are quite a unique design.

Last month you could read in HighFidelity what a CEO of YG Acoustics, Mr Yoav Geva, had to say about his loudspeakers. Not only do they use many interesting solutions for the drivers and crossovers, but also cabinets of their speakers are quite particular, being a key factor in achieving a final sound. These cabinets are made of aluminium slabs using vibration-free pressurised assembly, creating sort of monolith design, that reminds me of products of another American company – Magico.

Not more then 5-6 years ago using any other material for speakers' cabinets than wood (in one of its forms or the other) was thought to be eccentric (at best), possibly harmless but having nothing to do with "true" audio. These eccentricities included materials like: glass, concrete and aluminium. Today, after the audio world recognised the amazing Crystal Cable speakers (glass) and both above mentioned manufacturers of aluminium speakers, the general view on what is and what is not the "right" material for speaker's cabinet has changed significantly.

Thrax Audio Ltd., a manufacturer of Thrax products, decided to use most rigid, vibration-free enclosures for their products. Based on the experience of other manufacturers, they knew how to do it—it "only" required them to buy crazy expensive CNC machines. So they did. It didn't take long before they had such an advanced machinery and such an experience with using them that some renown European high-end  manufacturers started to commission enclosure production to the Bulgarian company.

A casing of the new power amplifier, Teres, looks like it was carved of solid aluminum block—the fit and finish is that good. Actually it was made of aluminum plates put precisely together, with outer surfaces of side panels  milled in such a way that they look like radiators.

This amp is getting really hot under stress as the current mode uses a pair of single transistors per phase. It is a unique design as there are only two gain stages in a cascode: a single penthode C3g in the input stage and JFET followers in the output. C3g is an octal tube with metal body. Input and output stages are coupled with a single transformer. There is no negative feedback loop.

When it comes to electronics aluminum casings are very common, even such advanced ones as Thrax's. But aluminum cabinets for speakers are still quite rare. Lyra speakers are the newest addition to Thrax portfolio despite the fact, that  Rumen Atarski's first audio project ever was speakers.

It is a two-way, three-driver design, with drivers in D’Appolito array. The concept is quite unique because of extraordinary rigidness of the cabinet, very special, aluminium bass-reflex port design, and very special crossover. The latter sports a huge capacitor for tweeter and that's it! Speakers and amplifiers use a high quality, user-friendly Furutech speaker binding posts.

A few simple words…
RUMEN ATARSKI - Thrax Audio | CEO
The story of Teres.  As you know Spartacus is our statement amplifier, 2 gain stages with Class A push pull output stage. Many people were scared by the exposed tubes and all were requesting a bit more power. So I started working on a circuit that will have a tube controlling a power MOSFET that can replace the output tubes in the Spartacus. Solid state and inductive loads don’t go well tighter and many devices let their gray smoke out. Fortunately for us new devices were introduced to the market that could withstand the high voltages and power required. This gave birth to a unique cascode system for the output. It is still operated at high voltage but not nearly as high as on the tubes. The output transformer used to load this cascode made it sound and behave as a tube amplifier and simplifying the input, as to be essentially a single stage device. So Heros was born.

A year later all our dealers started asking for more power and bigger amplifier with the same character. There was no commercially available output transformer of sufficient quality for power above 200W, so the only option was transformer less output stage. This automatically prevented the use of Heros driving system, so I went back to the drawing board. We resorted to the topology of Spartacus again and implemented it in Teres. we use an input tube for voltage gain and a transformer for phase splitting (same as in Spartacus), but here we replace the standard push pull output with 2 totally independent single ended followers based on a scaled version of our cascode. Running them out of phase to each other and sharing the load, forming a bridge that is unbalanced by the phase splitting transformer signal in order to be re-balanced trough the load with a mirror image of the same signal. The output stage has no character of it’s own, so the sonic color of the the tube stage is the overall character of the amplifier.

Regarding Lyra. The development started around a driver developed by BMS. It uses a ring diaphragm. It was patented more than 15 years ago. During the research for wide bandwidth horns at Spherovox new profiles with different directivity properties where developed. We just adapted one of the designs for high end audio.

It uses a custom "short" version of the driver and the special horn to cover the 1.5k-20k range with an outrageous sensitivity of 112db/W. We use a combination of the horn loading and the High Pass filter to tailor the response of the tweeter while severely attenuating it to mach the mid/bass unites. There is no stress for this driver at ANY level. It practically has lower intermodulation distortion than the amps.!

The 6.5" drivers are used only bellow the 1.5kHz crossover. This prevents them from exiting the breakup modes of the magnesium diaphragms. In order to get the perfect time/phase alignment the front panel of the speaker is carved from solid accommodating for the relative positions of the drivers. Geometry is optimized for listening distance of 3.5m. The solid aluminum prevents any vibrations in the enclosure and specially the front.

THRAX AUDIO in High Fidelity
• TEST: Thrax Audio MAXIMINUS + DIONYSOS + SPARTACUS – D/A Converter + preamplifier + power amplifier
• INTERVIEW: Rumen Atarski | Thrax Audio – CEO, see HERE
• TEST: Thrax Audio DIONYSOS - linestage, see HERE

Recording used for the test (a selection):
• Abraxas, 99, Metal Mind Records MMP CD 0102, CD (1999).
• Abraxas, 99, Metal Mind Records/Art Muza JK2011CD07, gold-CD (1999/2011).
• Aquavoice, Nocturne, Zoharum Release ZOHAR 077-2, CD (2014).
• Bob Dylan, Oh Mercy, Columbia/Sony Music Labels Inc. SICP-30579, Blu-Spec CD2 (1989/2014).
• Helen Merrill, Helen Merrill with Clifford Brown. Singles box, EmArcy/Universal Music LLC (Japan) UCCM-9336/8, "Limited Edition" 3 x SHM-CD (1955/2014).
• J.S. Bach, English Suites 1, 3 & 5, perf. Piotr Anderszewski, Warner Classics/Warner Music Japan WPCS -12882, CD (2014).
• Leonard Cohen, Popular Problems, Sony Music Labels SICP-4329, CD (2014);
• Leszek Kułakowski Ensemble, Looking Ahead, ForTune 0043, "No 031", CD (2014).
• Ludwig van Beethoven, Sonatas op. 109, 110 and 111, piano: Evgeni Korolov, Tacet 208, "The Koroliov Series Vol. XVI", CD (2014).
• Pet Shop Boys, PopArt: Pet Shop Boys – The Hits , Parlophone/Toshiba-EMI TOCP-66252-54, 3 x CCD (2003).
• Porcupine Tree, The Incident, Roadrunner Records/WHD Entertainment IECP-10198, 2 x HiQualityCD (2009).
• Queen, Queen Forever, Virgin/Universal Music LLC (Japan) UICY-15347/8, 2 x SHM-CD (2014).
• Sting, All This Time, A&M Records 212354-2, SP CD (1991).
• Voice Factory, Voice Factory Sings Chopin a Capella, Voice Factory, CD (2014).
• Zapach psiej sierści, soundtrack, music Włodzimierz Nahorny, GAD Records GAD CD 019, "Limited Edition 500 Copies", CD (2014); 

Whatever will I write later, whatever assessment will I pass I would like to send a strong signal already now to all electronic music fans, to those who like close, palpable presentation, and to those who expect not a huge space far behind speakers, but a close sphere built around listener sitting in its center: all of you can can search no further. If you can afford this system just buy it and keep it for ever.
It is a system of a very strong sonic character. What it offered might not have been exactly my cup of tea, but it did not matter at all. This time I didn't mind at all to fall for something offering quite different qualities from those I usually search for. The quality of the above mentioned sound features is so high that this Thrax system could be exhibited in the Museum of Sound as a perfect example of a high class, sophisticated piece of art.

Lyra speakers together with Teres amplifiers build a warm, rich sound that is also amazingly vibrant. This is obvious no matter what recording one plays, no matter what music genre. The precision this system forms the sound with, makes you wonder about choices of other  audio designers, in particular those who create loudspeakers. If you use Thrax amps with most of speakers using paper drivers you will realize that they tend  to mask problems generated by other elements of the system. Lyra show us that paper, which under certain circumstances sounds warm and soft, is used to mask a roughness, harshness of the sound.

I think that these solid, metal cabinets of Lyra speakers work in similar way. If one uses a low distortion, precise drivers in such z high class cabinets they will start to act as sort of magnifying glass providing listener with information about any problems originating from any element of the system. To use that to one's advantage one needs a very well designed crossover and a high class system driving these speakers.

Not all manufacturers utilizing paper or plastic cone drivers for their loudspeakers with wooden cabinets do that because they can't do any better. Anybody who knows JBL, Spendor or Harbeth speakers can vouch for that – these "antique" technologies and materials, properly used, deliver outstanding results. But more often then not using them will result in less favorable sonic results.

Thrax chose a different, I think most difficult way. There are only very few companies that took the same path and succeeded—YG Acoustics and Magico are best examples. Thrax system produces similar results. Anybody who claims that transistors produce a "cold" sound, and metal cabinets and drivers deliver a "dry" sound, has really no knowledge of the audio industry and audio products. If he based his opinion on particular products, these particular products must have been faulty and not the technology or solutions. The latter offer particular benefits, have some flaws of their own, but are surely not a bad choice—only a particular application might be wrong.

Was it because of elimination of cabinets resonances, or usage of amazingly linear C3g tube, (whose cousin,  C3m, I knew from some other top products), or most likely due to many elements working together, these speakers create a dense sphere made of air, sounds, details that surrounds listener. If only recording we play allows that. Because when we play a recording that was made in such a way, that we perceive sound as coming from far behind speakers, than Thrax allows the sound out of this sphere. That's how the latest Piotr  Anderszewski CD recorded in Warsaw with J.S. Bach's English suites 1, 3&5 from Warner Classics, sounds like. I have a version of this recording released in Japan. This type of production focuses on a soloist presented quite close to the listener, but it does not create a "wow" effect as there are not so many other sounds coming from sides or from behind us. It is not a very lively sound. Thrax system did not try to "light the presentation up", didn't try to deliver the very essence of the music, it simply conveyed the recording in a way it had been made proving why other recordings, like Anderszewski from Carnegie Hall sounded better.

Quite a different result we shall achieve with recordings where some spatial spatial effect were used, were out of phase sounds were used to create an impression of sound coming even from behind listener. These recordings create an impression of surround—multi-channel sound. There are quite a lot of such recordings. The best ones were prepared using the Q-Sound system, like, for example: Roger Waters' Amused to Deathor Sting's Soul Cages.

There are also some Polish interesting recordings of that kind. I really like the group Abraxas so I often listen to their album 99. They are representatives of so called art-rock (progressive rock), and this particular album was recorded in 1999 by Jacek Gawłowski, who received a Grammy Award in 2014 for Włodek Pawlik's Night in Calisia. For that album he was involved as a producer and a mastering engineer. He was also involved in a project of re-issue of first four Czesław Niemen's albums.

Anyway, on 99 between tunes there are additional pieces of music that include very special spatial effects. The reviewed system recreated those spatial effects in an amazing way. I have not heard any system (regardless its price level) that came even close to Thrax's performance. Bulgarian system delivered extremely rich sound, surrounding me continuously, without and division for front and back sounds.

This system will present in a very interesting way also some recordings that are usually not "liked" by most audio systems. I mean those recorded with microphones placed very closely to instruments, mixed from multiple tracks, usually as multi-mono—this actually means 99% of music material that's been produced for many years now. For example—the latest Leonard Cohen's album, Popular Problems. System delivers the foreground very close to the listener. It is a large scale, rich sound so it creates an impression that we sit in the first row, just in front of the stage. This manner of presentation was even clearer when I listened to Voice Factory album with  Chopin's music, sang (a Capella) by NOVI Singers (album comes from GAD Records). Microphones were placed so closely to singers that it created an impression of a very small distance between listener and singers standing in my room. The reviewed system provided also information about quite aw realization, not so perfect voiced were taken by microphones placed very closely.

Tonal balance is set quite low. Speakers deliver very clear, rich sound, with bass going really, really deep. The lowest octave is "indicated" mostly with higher harmonics, but these are delivered in almost perfect way which creates an impression that we listen to much larger speakers and the we can really hear even lowest notes.

Treble seems warm but also very vibrant. Cymbals sound seems bit darker than in reality, even slightly darker than delivered by my Harbeth speakers. But there is no "rounding" or "softening" of leading edge. It's a rare combination—sound are not "lightened up", and yet the decay phase is rich and long enough.

The key element of this presentation is midrange though. Many good things can be said about deep bass and rich treble, but they both seem to only complement midrange that is amazingly rich and complete. Images are not precisely depicted as they are presented very close to the listener. Their energy is extraordinary though. Sound is quite energetic despite the fact it is also quite warm.

This particular set of features should satisfy all fans of music I mentioned before, plus fans of electronic music. I believe that if Tadeusz Łuczejko, whom I met a few days earlier (a musician, member of Aquavoice, an organizer of Gorlice Ambient festival could have listened to his album Nocturne on Thrax system, who would have loved it. The sound was very essential, rich, mature but also very pure.

Summary

I have defined a potential owner of this system at the very beginning of this text. Thrax does not like compressed  signal, as it decreases scale of the sound, and creates an impression of the whole sound coming from area in axis in front of the listener. It does happen even with well produced recordings like Porcupine Tree's  The Incident. The whole structure of the music seems to fall apart, there is chaos instead. Thrax doesn't forgive that. Classic recordings with a lot of air BEHIND performers (and above them) tend to be re-interpreted as the foreground will be shown closer to us and there will be less of the air in a distance. Also phantom images won't have a real depth.

But if one listens to the music I mentioned before sound will be amazingly palpable. It will fulfill expectations of those who search for a rich, clear and close sound rather than presented in a distance. Depth of the sound in outstanding and I am sure that one could credit low-distortion drivers and resonance-resistant (coloration free) cabinets for that. Make and finish is top class. Also elements used for both products are of top quality. Rumen Atarski developed a system he can be proud of.

DESIGN

TERES
Teres is a monaural power amplifier. It is a hybrid design, with C3g pentode (in triode mode) in the input stage and transistors in the output stage. According to Rumen Atarski there are only two (!) gain stages. What's more, input stage (tubes) are loaded with transformer—it is the large cube in the middle of the casing. Behind it there is only a second cascode gain stage based on JFETs and MOSFETs.

Developing a device based on such a simple concept requires a lot of time and effort. At least if sound quality and good measurable parameters is what we want to achieve. Teres is uniquely simply design. Input section is placed on a PCB bolted to the back panel of the device. It includes almost complete power supply section for C3g. Power transistors are placed inside two small aluminum boxes. These have a shape of a section of cylinder. They are bolted to the sides of the device and they produce most of the heat one can easily feel after turning Teres on.

In the middle there is a large toroidal transformer and two large smoothing capacitors. On top of them designer put a small board with SiC Shottky diodes. This material called carborundum is used in many top designs, one of them being SPEC Corporation Designer Audio REQ-S1 EX phonostage.

Amplifier sports RCA and XLR inputs, but the device works in an unbalanced mode. Signal is balanced in coupling transformer. The whole circuit is controlled by a microprocessor that sits on separate board and sports a separate power supply. Teres works without negative feedback.

LYRA
Lyra is a two-way, three-driver monitor. It sports a vented enclosure that is made of aluminum plates screwed together. Also bass-reflex port is made of aluminum. A mineral wool was used for internal damping.

Drivers are screwed to the front baffle from inside, so the screws are not visible. A solid aluminium carved front panel incorporates a horn with specific directivity and frequency response. Its shape was developed by a company Spherovox. A ring diaphragm compression driver was custom built by German company BMS.

Two mid-lowrange magnesium diaphragm 6.5'' woofers work together. These look like top line SEAS drivers. They sport a magnesium membrane and copper phase plugs. They work below 1,5 kHz.

Loudspeaker sport a puristic crossover of  the 1st order, built of the most expensive elements including Mundorf silver capacitors and a huge coil. Even speaker posts were chosen to achieve the best sound quality—these are the same posts that are used in amplifier—Furutech FT-816.

The only thing these speakers miss are matching stands. For now any solid 70cm stands should be fine, but since these are high-end speakers they will show any problem with accompanying system including low quality stands.

Thrax Audio Dionysos preamplifier and Heros monoblock test review
Matej Isak

REVIEW SUMMARY: I can relate in a same way with Thrax Heros mono blocks. With the delicate power that some tube based power amplifiers might lack, Thrax Heros acted like no solid state or tube amplifier. They actually didn't act as any other power amp I heard. They've gone beyond solid state pure A class  sweetens and bring that natural there dimensionality and sense of space from tubes. A daring and puzzling combination, but it worked far beyond of what I expected. Remarkable!
Heros are not about power but about energy in motion. Its the effortless flow of music that makes Heros so darn warm hearted. You'll get struck by the intimacy and limitless natural nuances when music is being played. Especially with live acoustical recorded music, where one can instantly find and hear the what makes amp performance so elevated. 

Thrax Dionysos received Mono and Stereo most prestige Uber amp award for preamplier that I though I'll won't gave out anytime soon if at all. Dionysos is one of the best if not the best (when implemented in a right system approach) preamplifier currently in production. Yes, quite a bold statement. With almost mind boggling internal architecture that paves the respect to the past and incorporate contemporary solutions Dionysos shifts the paradigms of what is possible when dots are connected in both researched and audible way. This preamplifier now only shows, but screams loudly how many man hours, passion and attention went not only in inner and outer design, but into an actual listening.

EXTENDED REVIEW:  Another rare ultra highlight of 2013 arrived. Rumen Artarski company Thrax captured my attention during the shows and getting to know their philosophy more deeply via their website and correspondence with Rumen. There was something so different and "right" about it that dragged my attention again and again toward their products and philosophy.

FIRST ENCOUNTER
As I often stated, everything start from the first encounter; namely the shipping boxes, packaging etc. I really love when things are done right and in the best manner. Following wooden packagin further on, everything associated with Thrax product was refined and on the level I wish most companies would present them selves and their products. In ultra high end league, this is actually a must, but mostly fail to deliver. Why exactly? Dedication, pride of own works, respect for customers

Packing, manuals components design... All over achieved! Thrax Dionysos preamplifer aesthetics are a true piece of modern industry art. I always loved statement product in a state of the art enclosures, but Rumen really went far beyond ordinary in both inner and external design. High performance electronics executed electronically and visually in trueartisan way. This is a Thrax language of experssion.

Heros monoblocks are of the same calibre. With three dimensional looks and monument aura those are one of the best looking power amplifiers if not the best I'v seen! Period! And they sing!

PHILOSOPHY
Thrax Audio philosophy and approach strongly correlates with my inner clock and how things should be made according to my understandings and feelings about ultra high-end audio. From tube rectifiers, chokes, TVC's, best materials being used, simplicity of signal, remote, quality of build etc.

Here below are just three of their reminders and wake up calls to consider, but I strongly urge you to take time and go through Thrax Audio home page for their complete views. They are not there only to entertain, but they actually educate or reminds us on quite few important points:

Transformers. Why no body does that – and why they do only a partial job.

Transformers don’t measure that well. They have limited bandwidth and rising distortion at high levels and low frequencies. All those shortcomings are true, but would seem to be substantially better performing in dynamic conditions than ANY op amp. The effect is jaw dropping not subtle.

Why do we use triodes?

Audiophiles have been led to believe through published measurements at maximum output power and uneducated reviewers that single-ended triode amplifiers produce vast amounts of harmonic distortion. As a matter of fact triode vacuum tubes are by far the most linear amplifying devices in existence today. They produce the least amount of distortion, and that distortion is predominately second harmonic, which is the least obtrusive type for the sound. By contrast, pentodes produce greater distortion, and the third harmonic tends to dominate. A transistor looks at best like a very bad pentode.

Bring theory to practice – no feedback.

It is logical that a signal passing trough and amplification stage will have some distortion added to it. (In our case this will be almost only second harmonic.) Passing trough the next stage we will add distortion to the distortion generating a minimum amount of fourth order distortion and so on. (Pretty much like the effect of feedback described above)

Consider now the following: the usual preamplifier (tube or solid state) has 3 stages (input buffer, gain stage, output buffer), then the simplest power amplifiers have 4 stages (input, phase splitter, driver, output buffer ). And all this is dependent of the signal amplitude via an extremely nonlinear function.

In order to minimizs this effect the preceding stage of any amplification stage should have at least 2-3 times lower distortion than the latter. (Would that be possible when we have 7 stages in the signal path?) Minimising the number of stages reduces drastically the order of distortion and its inter modulation products.

The sonic result is vastly improved transparency and speed.

Our products feature the minimum sensible number of stages implemented with the most linear devices possible operating in the closest to theoretically perfect operating conditions achievable.

Result? You be the judge!

INSPIRATION
All great artisans never hide their inspirations. Many of us share the respect for Japanese audio legends and their heritage. They did rewake the magic of tubes (Triodes) and approached the creational stage with their cultural norms. Those norms makes them so different and in my terms better then most other designers. It sets the artisan way. As they created a legend they followed the legends. Thrax Audio elaborate shortly:

"The works of Japanese tube gurus are a source of inspiration for us. Shishido San's designs with transmission triodes manifested trough Wavac Audio and Kondo San's creations at Audio Note Japan are the best examples of the Japanese vacuum tube art currently in production and the different approaches taken to achieve the same goal. Their attention to detail and manufacturing quality inspired us to try and do better. The works and concepts of another Japanese designer came closest to the direction in which we were heading. Never implemented commercially, however, the designs of Sakuma San are a tough example to follow. Directly heated triodes with inductive loads seemed to deliver the effortlessness and tonal richness we are after."

THE ONLY WAY
For me there are only two ways to ultra high-end heaven (with one or two exceptions, think Excalibur). Pure A class solid state or best executed tube circuits often or as a rule in A class. Outside of this territory products might sound fine and even above good, but never great in the ultimate sense. It seems that some rules of basic understanding must be followed to achieve state of the art high-end reproduction. And a talent to recognise and implement them.

It is my joy and pleasure to see and hear Thrax Audio venture going totally out of the box and above all trends to create their products in a stunning audible way. This is what  true high-end dedication means.

PURE AND PERFECT
I'm perfectionist by nature and love refined manufacturing combined with the great industry design. Both Dionysos and Heros are an example of what ultra high-end components should look and feel like. From handy remote, that reminds of Mobiado mobile phone to fine artistic details of Dionysos front plate. If you cannot appreciate meticulous CNC work and finish of this preamplifier then you must have other issues rather then respect for finest craftsmanship. I can spot the anomaly in design within seconds. It's just how my inner clocks and aesthetic sensors work. Both gift and curse at the same time as it's hard to get pleased and satisfied. Perhaps it's even peculiar. But, the thing is i can spot the un-perfection from a distance and it irritates me like anything :).

I love premium feel of things regardless of product type. Thrax products are carrying premium feeling that radiates an instant feeling of proud ownership and substantial luxury. Not in a snob like way, but with a certain aura that clearly reveals the elegancy and profound taste of man behind the company. My urge for things being done right is so rarely addressed with most high end audio products that usually feel rather mediocre in their appearance and design, then something that cost like a car or house.

Dionysos preamplifier and Heros heros monoblocks are wonderful examples of not following the crowd. Not only with their aesthetics, but as you'll find out in next lines also with what matters the most. Sound and music!

SWEET INTOXICATION OF MUSIC
I'm an indépendant and without any need to flatter anyone or follow up to advertising money to justify my writing. I can simply write through my passion and freely choose what to test and write about. Mostly I'm after the stand out products that boil my blood. Those who deliver music in its purity and potency. In that search I'm not bound to the price restriction. Both above and below. Thanks God!

Along Kondo Audio Note Japan and Robert Koda so far I simply didn't stumble upon the electronics that could ewoke such an unique musical impact as those two companies can project. Thrax joins them with big pace and it seems that even transcend at few points of Kondo unmistakable delicacy of intoxication.

Even from the first few notes being played through the Thrax Audio Dionysos preamplifier and Heros monoblock combination I was being shot directly into the vein with what Dionysos and Heros could present. A true blissful venom :). The sweet unstrained flow of music presented in a way of Monet and Degas witty view the world. Full of colour vibrancy and feeling of being there. And most importantly with the impact that last and stand continuously. A lot of high-end audio components might impress you at first glance. When you return to the listening, their initial impression fades. Through my listening notes that never happened with Thrax and I'm as excited with the music flow as I was on the first day. That should tell something right!?

With Thrax combo intimacy of sound and musciality hits you at such scale that leaves most of the gear of current high-end market light years behind. Bold statement right!?  Here are at workings something that few seems to understand or even write about. Not that I feel egocentric of special, but as I don't have to think in narrow or guided way perhaps this gives me a better position. And I'm used to high-priced high performance gear. I don't get scared or confused easily.

Thrax evoke the energy of motion. The purity of music untouched and so potent in its power to interact with listener without borders or constraints. At stake...  It's not only a matter of electronic design being used or implemented, but a subject of art and culture. The fact of the one's view of things general and particular. Choices being made and implemented.

Both Dionysos and Heros give such an impact and it feels so right. How is then that some fail to understand such products. Simple. People get scared of emotional potency and exchange! Over my twenty some years I've seen and heard quite an array of what supposed to be the best of the best. Based on numbers and some reviews those might hold some wicked titles, but at primal role of music reproduction at highest level they most fail to follow up those claims of state of the art. Ultra high-end is not a matter of background listening visionary of most. It's to be experienced directly and non altered. I know live and acoustical music by heart and play few instruments. Being in constant reset of subjectivity keeps me focused and objective. When it comes to the highest judgments I do think its a must to set a certain level of performance. Ultra high-end audio is a science by itself. It takes efforts to create those exceptional devices and it also takes mileages and efforts to understand and recognise them. Like with state of the art food, wine or horology. You cannot become an artisan or distinguish between the mediocre and the best in an easy way. It takes time and dedication on both fronts.

MUSIC
There is something special in the way that few of true state of the art products behaves. It got to do especially with inherited power of music. How it connects with us on the sublime level where things are on the emotional plane and far away from technicality being main reasoning act. It's true, that knowing music scales, history and philosophy helps in appreciating music more. Like with like an art.  It adds to experience, but not by default. It enriches you. Once you discover the historical time travel anchors of scales, movements, passions and pains behind the roots of past musical creations the primal impact is even more direct. Perhaps even poignant to a degree based on music material being listen to. But, for true emotional exchange all those variables are not needed, but they're welcomed.

We can argue a whole day long or until the cows go home about how certain audio component do or don't connect us more intimately to the core of performers and their intimate world, yet something do happen with certain audio reproduction devices. What is this exactly we fail to measure and I doubt we ever will, but we can understand a little portion to a certain degree with the overview of the technology being used. Of course when right strikes being taken. Not blindly, and in most cases not straight of the book.

Our expectations towards ultimate playback should be sky high. As prices. Sharp and direct. In the sense of ultra high end audio we're not buying into luxury segment, but a luxury performance that raises all the bars. I highly enjoy the complexity of any extraordinary design, but if it's only an outhere shell then what's the point. There are to many of such jewellery boxes out there. What I want and hanker for is an extraordinary musical box. Thrax made both wining strikes. With performance and looks. As mentioned above Dionysos looks like no other preamplifier. It's an art form of industrial design being taken seriously and above ordinary. It act as statement in physical appearance and sound performance. In a sense this is a true functional art for the music enjoyment of highest calibre. With Thrax form follow function and vice versus. Quite rare and wicked example :).

ANALOG TRUTH
Just in time I received Chad Kassem latest version of Getz/Gilberto Girl from Ipanema LP on 45rpm. Now if you need to buy one album per year here is your desert island choice. As with Acustics Sounds Analog Production of Nat King Cole Love Is A Thing analog is as great as ever. Some of the latest analog reissues or contemporary recordings like Norway's 2L digital to vinyl releases brought such a high performance to vinyl, that digital simply watch the burning smoke trail left behind by few miles. If you want to reveal a true potential of any given system then full state of the art analog front end will show the truth. Thrax combination is most enjoyable one brand system I have had pleasure to listen in my demo room. I put a lot of smilies in my listening notes and clearly noted my enjoyment of music and forgetting about the world.

I always do a reality check with the LessLoss set of product. They are my "trade standard" for testing the refinement of things. DFPC power cables quickly show the level of importance of quality cabling on any device. With Dionysos and Heroes the impact was not subtle and it only further showed the true capability of both devices. Analog is my medium of preference for reference performance and this is also where the LessLoss Firewall shows its sublime workings. Combining all this, and with an added Blackbody as Cherry on Top, the neutral performance was made clear. As written in my previous reviews of LessLoss products, they bring balance to performance and show the real potential of any given gear. With both Thrax components and LessLoss in a system they really enter the realm of state-of-the-art replay.

TRUE HEROS
As with Robert Koda Takumi K-10 Thrax Heros pulled the trick of illusion where one loose the objectivity regarding technology being used. In a blind test you cannot figure our if Takumi K-10 is a solid state or tube preamp. It holds all the attributes of tubes, but with the advantages of solid state. I can relate in a same way with Thrax Heros mono blocks. With the delicate power that some tube based power amplifiers might lack, Thrax Heros acted like no solid state or tube amplifier. They actually didn't act as any other power amp I heard. They've gone beyond solid state pure A class  sweetens and bring that natural there dimensionality and sense of space from tubes. A daring and puzzling combination, but it worked far beyond of what I expected. Remarkable!

In the upper echelon there are quite few solid state amplifiers that uses a pure class A at their heart core. Take Gryphon, Vitus etc. for example. While they performance brings certain intimacy nothing compare to the purity of Thrax Heros. They don't strain music in any way with dynamic imprint that still take away the "full magic" as with those establisehd pure Class A amps. Heros actually liberate music from solid state "cuffs".

Thrax Audio Heros looks different, perform different and act different. I can imagine only one amplifier being taken to the other shore of things beyond and that's Robert Koda Takumi K-70. I haven't listen to those monoblocks yet, but they're coming for a review in due time. 

THE DIONYSOS
Thrax Dionysos is a true ultimate component that you build your system around. You can start with it and elaborate when time and funds allow. Its performance goes ming boggling above the given price and fluidity and emotional impact makes you rethink about some of those pricey Japanese products. 

If Dionysos resembles the language of Rumen Artarski then all my respect and ego bow down to his efforts. This preamplifier is the labour of respect and love for music and all around approach with premium feeling makes one desire it even more. 

You may execute your need for branding, but there is no way to logically and emotionally pass the Thrax Dionysos when you're in the need of system change or in a hunt for state of the art preamplifier. Dionysos redefine the price structure and audiophile money being spend. Even when money not being subjet matter, you'll have the hardest task to find a competitive preamp. 

Like with IWC, Patek Philippe, Rolex etc. The feeling of handling things around Dionysos is prestigious and refine in most ergonomic way. Everything makes sense and I simply love the clear, clutter-less front plate without any prints. Anyhow. In few strikes you'll know your way around and enjoy operating it with ease.

In an Apple kind of way there are no visible screws or bolts on chassis. Design like this takes time and dedication. Result is an unmistakable aura which makes Thrax flagship preamplifier unique and stand out from the crowd. 

Thrax Dionysos received Mono and Stereo most prestige Uber amp award for preamplier that I though I'll won't gave out anytime soon if at all. 

CONCLUSION
I wrote this review in a bit different way. Above are links connected to the operational manuals and specifications for both products. With Thrax products under review I wanted to share how special and different they are. As products in league comes rarely on market, I felt a need to present them as special and unique.

If any other company would packed so much high priced modular parts and add on all the R & D of Thrax Audio Dionysos would cost a fortune and quickly jumped into the territory of sky high priced preamplifiers like Kondo M1000 etc. You can rant as much as you want with my next statement, but at given price Thrax Dionysos is an actual high-end audio bargain. If we only break down the parts cost and quality of chassis you'll will quickly gave a wake up call for most ultra-high end companies. Money have to come from Rumen Artarski other operations. I highly and openly respect this.

Thrax Dionysos is one of the best if not the best (when implemented in a right system approach) preamplifier currently in production. Yes, quite a bold statement. With almost mind boggling internal architecture that paves the respect to the past and incorporate contemporary solutions Dionysos shifts the paradigms of what is possible when dots are connected in both researched and audible way. This preamplifier now only shows, but screams loudly how many man hours, passion and attention went not only in inner and outer design, but into an actual listening.

Heroes possess an intricate translucent nature that reveals music for what it is......rich in tonality, zesty and radiant are capable of harmonically contoured reproduction that is both elusive, lyrically and most important reiterated at each play
Matej Isak

FIRST CONCLUSSIONS: Heroes possess an intricate translucent nature that reveals music for what it is. Most potent medium of profound interaction between performer and listener. Heroes, rich in tonality, zesty and radiant are capable of harmonically contoured reproduction that is both elusive, lyrically and most important sound wise reiterated at each play.  

Thrax team shows profound dexterity and they are stalwart to the Rumen Artarski strong determination regarding to how Thrax products should sound like. 

The unrestrained, enchanted music flow is most inspiring. Heroes hybrid concept brings most inspiring level of transparency, details and constitutional points of upper echelon league of the performance. For any Class A amplifier this is quite an achievement. 

EXTENDED REVIEW: I’m more then thrilled with what we could set down as a power amplifier mecca test of comparing the illuminating Thrax Audio Heros and Teres power amplifiers. As a top of the cherry the Spartacus mono blocks will join in at at a bit later date to conclude the complete the exploration of the current production of Thrax power amplifier line. 

As you can read more in depth below all new Thrax products are born as a complete different approaches to the ultra high  end reproduction of the sound. So these power amps do actually  not compete with each other, but offers a variety of choices suited to different system setups. And before you ask why Thrax is offering a such array of amplifiers the answer is very simple.  Because they can! Intriguingly inspiring…

Heroes mono blocks represent the company finer exploration of Class A Hybrid tube fet technology. They offer 100 watts of Class A via unique hybrid transformer loaded amplifier design that embrace the renowned concepts with the contemporary high tech. You won’t see output transformer in typical Class A amplifier and still you’ll find them in Heros. Its not a non working concept, but as following this route cost a money. I love the logics behind such concept and the difference is as factual as it gets. But more about this latter. 

Teres on the other hand is a transformer coupled hybrid power amplifier based on classic tube amplifier topology. Single ended tube input stage is loaded with a phase splitting transformer, which controls two separate single ended amplifiers out of phase for output. Teres implements audiophile super long life C3g input tube, silicon carbide rectifiers, shunt regulated power supply, solar cell bias of output stage, battery bias of input stage and microprocessor controlled operation. They have no feedback, uses special grade screened power transformer as well as JFET/MOSFET cascode output devices. Now if thats not enough to get you interested, then recheck of many priorities is mandatory. 

In my preview of the Thrax Audio Orpheus phono preamplifier here: link I already gave a great overview and insights of this Bulgarian High End audio manufacturer. Anyhow… To wrap it up shortly. These days you’re rarely encounter such a proficient, self sufficient and highly resolved manufacturing premises. And one needs to understand the Thrax Audio for what it really is to appreciate it on the level its deserves.

Driven by Rumen Artarski unlimited passion for highest possible musical reproduction Thrax Audio unique venture is more of the extreme, ultra high-end audio design laboratory then your typical high-end audio manufaktur. 

Few months ago at my company/factory visit I’ve had a chance to see and understand the inner workings of Thrax as company. It was an eye and mind opening experience that led me to respect it even more. 

Anyone knowing Rumen feels the similar about him. He’s one of the rare connoisseurs and high-end audio aficionados. Broadminded and culturally embossed person with and exquisite taste and knowledge that surpasses your typical expectations. 

Thrax Audio spirit for me reflect the traditional Japanese approach to the production process where the creational phase is as important as the end result. One must really see Rumen collection of rare tubes, exotic output transformers, chokes etc. to fully understand the dedication and unabridged enthusiasm. There is simply no other company doing the things the way Thrax Audio operate. This is also due the Mr. Artarski being a successful business carrier, that created an immense safe grounds for the in depth R & D of the Thrax Audio product. They can have a complete different time frame and research complexity then most of the gear out there. As a company they are not hard press from the very first moment that new product development starts. No typical taximeter ticking clock is needed. This leads to a complete different sets of the products that can operate on much very different and proficient level. 

We discussed many things with Rumen, past and present at my visit and over our corespondency. I wanted to understand his mindset and why he’s pursuing his venture the way he does. I’m no rookie when it comes to the history of high-end, basic designs, different topologies etc. But during our conversations I’ve found myself hitting the conversation stop button too often! Yes, he’s done his homework overtime and overloaded.

Seeing the literature, prototypes, schematics and amount of contemplating behind the products left a lasting impression with me. It still resonates and it’s a great reminder whenever I’m starting to contemplate about the actual meaning of high end audio. Being inspired, my reading was revived with much more complex material.

HEROS AT WORK

These days I’m not lightly inspired or awaked out of the equality of all the gear coming in and out. Thats why many times I don’t even explore further if a certain criteria is not met. Regardless of the price. 

There are so many mediocre high-end audio products eschewing the chewed circuits and designs, that its not even funny anymore. Call it a matter of globalization and greed in a simplified reasoning. A clear indication of non strange logical conclusion of why most of the sound results of amplifiers are bland and boring! Its also a matter of the goals wanted to be met. For most companies the main ruler is a quick turn over and cashing in. Whit this kind of modus operandi what can be expected as the end result? Saving on the everything and calculating to the last bit leads to employment of electronic engineers knowing little or nothing of the high-end and ultra high-end audio industry mechanics. Initial job of proper design and “voicing” in most cases actually never happens. 

There is a huge difference between designing a typical amplifier and high-end audio counterpart. Many tried to cross the bridge from the other side, but few of them succeeded. Thrax Audio employs the people with specific high-end audio skills and with decades of particular experiences. Sometime, if needed they would bring in the top most specialists, even if only for the  specific project being developed. 

And the difference between typical and ultra high-end audio potently designed power amplifier? Night and day! Not even a debate is needed when comparing the sound of such two side by side. 

This is why I’m pushing the agenda of intelligent research and making the proper homework for people are in the process of upgrading the system and changing or purchasing new high-end audio components. I do believe in common sense and intelligible nature of people willing to shelve out such a hefty amount of the money. 

DESIGN AESTHETICS

Bauhaus, art deco, with unprecedented elegant simplicity, that cuts with the contemporary aura and fails to be ostentatious like most of the high-end audio gear at any point. Elegant and timeless. Love it!

FAMILIAR LANGUAGE 

Thrax Audio Hero power amplifiers have shown their DNA and recognized sound orientation from the first few notes being played. They carry the familiar “voicing” I’m used to from the Dionysos and Orpheus. Continuity is not easily achievable. Especially with building different components one wants to open new, uncharted territories, yet without loosing the most important orientation. And for Thrax this is clearly the sound of the real music. 

There are many critical points that embarks a level of needed attributes to let any product reside on the plane of the high-end audio. What to talk about the ultra high-end, even more niche market. Thrax Heros sits both firmly and boldly on their designated throne without even blinking…

SOME MUSIC

Leonard Cohen last two albums represents some his finest music up to date. They are both very well recorded and can easily reveals whats is possible within any system. Call it simple pop or whatever you want it. To really sing these songs needs more then properly designed electronics. Same demand goes for Lokua Kanza latest album Nkolo. Pure impact of the african lyrical compositions. Simplistic yet complex at the same time. To get into the core of the songs like Elanga Yu Muinda is no easy task. Here even few of the best specced amps fall short of the vibrancy needed to encompass Lokua soulful composing. 

Grieg Unheard Reza e iRagazzi fantastic album is another album encompassing majestic execution that really needs a profound amplifier in order to come alive and Janos Starker protégée Maria Kliegel endearing playing falls even more so in line of the proficient demands and sound attributes.   

Thrax Hero mono blocks step a further into the rendition these albums and artists with an unfettered hologram like three dimensionality. They could render the music under the scope precisely and with the omnipotent dynamic barrage which can minutely shift from pianissimo to forte fortissimo without a sweat and without loosing a pace. Even most importantly the essence of music is touched and revived withe Heros. 

FIRST CONCLUSSIONS

Heroes possess an intricate translucent nature that reveals music for what it is. Most potent medium of profound interaction between performer and listener. Heroes, rich in tonality, zesty and radiant are capable of harmonically contoured reproduction that is both elusive, lyrically and most important sound wise reiterated at each play.  

Thrax team shows profound dexterity and they are stalwart to the Rumen Artarski strong determination regarding to how Thrax products should sound like. 

The unrestrained, enchanted music flow is most inspiring. Heroes hybrid concept brings most inspiring level of transparency, details and constitutional points of upper echelon league of the performance. For any Class A amplifier this is quite an achievement. 

I’ll continue when a pair of Teres mono blocks will hit the shores of Mono & Stereo HQ’s. My venture came to the point where I can be very selective in my choices of the products being reviewed and tested. In this way more focus and listening can be dedicated to the stand out equipment. Thrax Heros certainly represent a healthy new breeze of the products being more than worthy of highlighting. 

Stay tuned….

,,,,,,,,,,Matej Isak

My New Reference amplifier...
Key Kim

REVIEW SUMMARY: Listening to orchestral music once again presented the amplifier’s innate ability to paint a realistic three-dimensional picture of the live event. The Teres recreated a soundstage with floor-to-ceiling, wall-to-wall spaciousness that was seamless while never once oversized. It rendered large-scale symphonic works as well as the Karan with a seemingly limitless dynamic contrast along with a powerful and full bodied low-end. Dvorak’sNew World Symphony No.9 in E Minor, Op.95, with Fritz Reiner conducing the Chicago Symphony Orchestra (JVCXR-024), produced enormous size, scale, and, more importantly, realistic dynamic swings. Whenever I cranked up the volume, the Teres kept its composure under whatever sonic onslaught that came down the cables.

the Teres hybrid mono amplifier brings so much to the table that, relative to other reference amplifiers in today’s market, it’s a bargain. They produced magic with every listen including a new reference of quiet, speed, and transparency. Timbre rightness coupled with color density and warmth is what ultimately won me over. Hats off to Rumen Artaski for creating a new benchmark so close to his superb sounding Spartacus, with lower voltage and no exposed tubes and can be used with mainstream loudspeakers. The Teres has earned my Stereotimes 2015 “Most Wanted Components’ award. Highly recommended!

EXTENDED REVIEW: I’ve reviewed Thrax Audio equipment over the years and found it to be what I qualify as the cat’s meow. In fact, I admired its craftsmanship and musical prowess so much that I chose the Dionysos as my new reference preamplifier over my Karan Acoustics preamp that had been my workhorse for nearly a decade. Rumen Artarski, founder and chief designer of Thrax Audio stated in many discussions I've had with him that “Thrax Audio components are highly addictive and once exposed to Thrax you are not the same anymore”. I was warned. Now I’ve got the Thrax bug. And that ain't good!

Thrax Audio’s latest product, the Teres Hybrid mono amplifier, is the subject of this review. Artarski told me about two years ago that he wanted to design an amplifier to sound as close as possible to his superb sounding Spartacus, with much lower voltage and no exposed tubes, to be used with more mainstream loudspeakers. Unfortunately, it is impossible to totally replicate the sonic signature of the Directly Heated Triodes and transformers used in the Spartacus. The Spartacus was designed primarily to drive efficient loudspeakers with maximum refinement. Keeping the sonic signature and specific presentation of Thrax gear in check, the Teres was created. Teres is an innovative design that still follows the “less is more” approach. Interestingly, Teres uses two separate and discrete output amplifiers completely independent of each other. Each consists of a single JFET/MOSFET and bias logic devices that were derived from computer and motor drive applications. Artarski is open minded and loves to think outside of the box. 

To make the Teres perform as intended, Artarski resorted to a new type of shunt regulator circuit for the input stage and a radically new bias method for the output stage. Artarski utilizes battery bias in the input stage to provide the cleanest signal path for the ultimate C3g tube (a minimum lifespan of 10,000 hours!) that drives the phase splitting transformer. Solar cells are used to bias the output modules; any other implementation would have required some electrical connection between the output stages, but with the solar cells they are totally independent. Cleverly, silicon carbide diodes are used which have no reverse recovery. They make for cleaner switching (and are gaining momentum in audio). Two output stages feature very high input impedance and do not affect the sound character of the transformer loaded input stage. The Teres uses zero negative feedback in any form; the load has no connection with the input stage and cannot affect it. This gives stability of tonal color and a low level resolution. Teres uses interstage transformers to create two identical out of phase signals that feed the two output stages. The Teres output impedance was reduced and the output stage is now DC coupled to the speaker in order to handle the huge currents needed by inefficient loudspeakers. Lastly, the input stage is totally isolated and optimized for all the voltage gain defining the sonic character. Teres can output up to 250 Watts per side into 8 Ohms without a shift in sonic signature and keep all the low level “space” information at the same time. Teres incorporates a new type of shunt regulator circuit for the input stage and a radically new bias method for the output stage, utilizing, as I noted, clever solar cells to generate the floating bias voltage.

The Teres mono amps arrived in sturdy wooden crates with thoughtful carrying handles. First class all the way. Just as I remembered when reviewing the Spartacus and the Dionysos. Artarski is a perfectionist; every little details counts from the components he chooses to the final details in shipping as well. He wants to make sure everything is flawless. I concur. Removing the screws opens the wooden crates to reveal how professionally the amplifier was packed. Thrax’s build quality is impeccable and the Teres mono amps are exquisitely crafted; fit and finish is top notch. The chassis is stunningly finished in solid aircraft aluminum plates and the chassis looks as if it were carved out of solid aluminum blocks. Brilliantly, the outer surface of the chassis works as a heat sink. Indeed, the Teres never got above warm to the touch, even when listening to symphonic music at realistic levels. The Teres is manufactured using Thrax’s ultra state of the art CNC machinery. Cleverly, it has a stand-by switch, which doesn’t need to be turned off after each listening; it remains on stand-by. With my Karan a solid-state amp, I was able to leave it on 24/7. But with the Teres it gets even better; I could put the amps on standby, which turns off the tube and leave the circuits on. This way it sounds really good from the moment you start playing the next time. In fifteen minutes you are playing at the components full potential! On the back of the Teres there are both XLR inputs and RCA inputs and it is equipped with gorgeously crafted Furutech speaker binding posts and IEC. 

Artarski told me that the Teres had been through 72 hours burn-in time in the factory to ensure sound quality and workmanship. However, he recommended 150 hours of burn-in time to fully settle it in after its arrival. I started listening right after a quick setup and right out of the box, I knew this was going to be something very special. As I logged on more hours the Teres started to gain more bloom and harmonic beauty. I’ve been looking to upgrade my Karan with a new reference and lately I’ve reviewed many great sounding reference amplifiers like the Concert Fidelity ZL-120V2SE, Reimyo KAT-777, and Franck Tchang's ASI Grand Stereo. These are superb sounding reference amplifiers; especially the ASI, and they bettered my Karan in every possible way. But for some reason I didn’t pull the trigger; I wanted a little more tube magic in my new reference amplifier. My readers by now know that I’m not the type who jumps ship to the “flavor of the month.” My reference Karan amplifier served me well as it did everything just right, was built like a tank and was - most importantly - trouble free for nearly 10 years.

My reference system has evolved and improved, thanks to Rumen Artarski from Thrax Audio. I’m really loving my new Thrax Dionysos preamplifier which of-course has a symbiotic relationship with its brother in the Teres mono amps. Cables are the unbelievable sounding Enklein David cables throughout the system (review on the way). Also (lucky me), near the end of my Teres review, I received Thrax Lyra speakers which were quite a surprise both in terms of their arrival and performance.   

Music to my ears

Normally I would let a component burn-in for about a month or so and then I would start to listen discreetly. Not with the Teres. My enjoyment started immediately but only got better as I put in more hours. The Teres possesses a very quiet and super transparent footprint and produced a mesmerizing three-dimensionality stage. So much in fact, the Teres sounded as though I moved my speakers further away. I didn’t hear any tubbiness but rather its performance was more graceful, gentle, and at ease. Images were more solid in a holographic space and were more liquid. The Teres’s solid-state output revealed itself more acutely, particularly on the bottom, where excess bloom gave way to greater dynamics, grip and speed. The amps had immediacy and were rhythmically alive producing a punchier, more direct life-like sound; yet in no way was the sound clinical, harsh or harmonically depleted in any frequency. This all resulted a seamless, top-to-bottom wall of sound by way of my Consensus Audio Engineering Conspiracy loudspeakers (and Thrax Lyra loudspeakers: which by the way produced a taut bottom-to-top transient response and an excellent overall speed without sounding etched or analytical).

One listening session I was in the mood for a female vocalist. I put on my new reference vocalist, Melody Gardot’s “The Rain” from MY One and Only Thrill CD (Verve). I was introduced to her beautiful voice at last year’s Munich show in the Silbatone Acoustics room. They played a tract, on her CD entitle “Your heart is as black as Night”, and it was a thrilling experience. Silbatone Acoustics tube electronics from Korea showcased Melody's astonishing voice through a majestic sized set of Westin Electric 1936 theater loudspeakers. Melody Gardot’s performance was beautifully rendered to the point that I was almost fooled she was in the room. As soon as I got back to the States, I ordered the album and since then it’s been added to my reference recordings. I put on “Baby I’m A Fool” and the music flowed exquisitely by the Teres mono amps not quite to the level heard by those Westin Electric, but still quite impressive. Vocal and instrumental timbres proved spot on, thanks to the Teres robust, full-bodied midrange. The Teres mono amps gave the music more life, the ability to deliver pace, while maintaining its natural character. As much as I love my Karan, the Teres mono amps performed better. The Teres reminded me of the Spartacus which I reviewed (here). Melody's vocals startled me – first by the immediacy and solidity of the image –  then by the improved complexity of her phrasings. Her sensual voice possessed a more tangibility, textures and tonality. Everything that I have come to expect from a Rumen Artarski design. Then some.  In the end, the Tere's presentation of this remarkable recording proved to be tonally, dynamically, and rhythmically more captivating than anything I've reviewed thus far. Quite a soul-stirring affair and what this hobby of musical appreciation is all about.  

The Teres boasts and uncanny solid footing in both worlds: it has the right amount of tube glow and solid-state control and speed. The best solid-state amps generally produce greater transient speed and clarity, better dynamic contrast, and superior bass extension and control. Predominantly, solid-state designs deliver levels of transparency that few tube designs can accomplish. However, compared to the best tube designs, even the best solid-state amps can produce an overhyped transient attack not generally associated with live music and it can sound harmonically flat. And often, solid-state’s superior transparency is accompanied with an analytical and crunchy sonic aftertaste, with the leading edges a bit unnatural. Tube amps, on the other hand, are generally harmonically overripe and sound richer than life; they are slower and softer than life on transient notes, but they lack solid-state’s control on the bottom.

I put on a familiar recording of Bill Evans’ Alice In Wonderland (JVCXR-0051-2) and the sound can be best described as liquid and beguiling. The Teres revealed a blacker background and an ability to paint vivid tonal colors. Paul Motian’s shimmering cymbal work came alive with incredible sheen and naturalness that was neither tube soft nor solid-state hard. Scott LaFaro’s double bass sounded as striking as I’ve ever heard on this recording. This legendary trio were natural and yet their attack never drew attention. The sustaining of their notes and their resonance decays were reproduced with an uncanny naturalness. Timbres are richly portrayed, with a density of color and warmth that makes even the best solid-state sound ever-so-slightly more mechanical. The Teres resolved tremendous amounts of detail without ever sounding overwhelmed, etched or analytical. The Teres has a remarkable ability and a realism that conveys a vividly convincing illusion of live instruments.

Listening to orchestral music once again presented the amplifier’s innate ability to paint a realistic three-dimensional picture of the live event. The Teres recreated a soundstage with floor-to-ceiling, wall-to-wall spaciousness that was seamless while never once oversized. It rendered large-scale symphonic works as well as the Karan with a seemingly limitless dynamic contrast along with a powerful and full bodied low-end. Dvorak’sNew World Symphony No.9 in E Minor, Op.95, with Fritz Reiner conducing the Chicago Symphony Orchestra (JVCXR-024), produced enormous size, scale, and, more importantly, realistic dynamic swings. Whenever I cranked up the volume, the Teres kept its composure under whatever sonic onslaught that came down the cables.

Conclusion

Rumen Artaski was right, the Thrax Audio is addictive and I need HELP because I am hooked. Yep, I pulled the trigger and purchased this review sample. Ladies and gentlemen, it’s that good a product. At $30k, It’s not inexpensive but the Teres hybrid mono amplifier brings so much to the table that, relative to other reference amplifiers in today’s market, it’s a bargain. They produced magic with every listen including a new reference of quiet, speed, and transparency. Timbre rightness coupled with color density and warmth is what ultimately won me over. Hats off to Rumen Artaski for creating a new benchmark so close to his superb sounding Spartacus, with lower voltage and no exposed tubes and can be used with mainstream loudspeakers. The Teres has earned my Stereotimes 2015 “Most Wanted Components’ award. Highly recommended!
...... Key Kym.

the Dionysos is a fantastically made brilliantly featured one-box preamplifier that sounds as good and in some aspects better than far bigger twin-chassis efforts from firmly established companies. Bravo, bravo, bravo!!!
Wojciech Pacuła

REVIEW SUMMARY: The sound of the Thrax is very open. It is not ‘electronic’ ....Here it was simply brilliant – precise and expressive without a trace of brightening or perceptible distortion.....This allowed the Dionysos to act very dynamic and expressive. To reiterate, expressiveness at this level of execution does not involve strategic coloration or irritation but simply shows events more verbatim like reality. This was aided by terrific dynamics.
There isn’t much I can say about the midrange. It was simply wonderful - smooth, full, precise, energetic and superior to any preamplifier I've heard to date
The bass was exceptionally potent, full and dynamic. It had impact when needed, was fleshy and when prompted by the recording almost not discernable. Usually bass occurs ‘somewhere in the background’ and midrange and treble are built atop it like a crouching tiger and hidden dragon.

Preparations for this review took me and Thrax Audio more than half a year. When I spotted their products for the first time at the Munich High End 2010 show, I knew I had to listen to them more closely. They had shown big tube monoblocks with large triodes in the output stage resembling Ayon’s tubes crowning splendidly crafted enclosures. After returning to Warsaw I emailed the Bulgarians asking for review loaners.

Their answer arrived promptly: "Currently we have three products as you can see on our website. In production and on sale at the moment is only the Dionysos preamplifier. The Spartakus monos should be ready in the 3rd quarter of this year and the Orpheus phonostage probably in the 4th.

"Because the development of our products consumes much time, we decided to present pre-production samples to a few people and are now booked solid with orders. Our production capabilities are fairly limited and we would prefer to have our friends listen to the products first because then we will have trustworthy feedback. Taking all of this into account we think we can send you our preamplifier for review by the end of July."

As is usual in such cases, the target date moved by a few months but one fine afternoon the courier brought a nicely looking wooden crate with the preamplifier packed inside. (Actually he didn’t bring it on his own. I first I had to file a complaint because the courier did not want to carry the crate.) This is how all audio products should be packed, not in cardboard boxes which devolve into something not even resembling a box after just one shipment. Everyone needs something far more sensible to really protect their precious cargo. The top of the Thrax crate was adorned by a milled or heat-stamped company logo which I really liked. 

The preamplifier itself turned out to be equally interesting. Online pictures don’t present more than a shadow of what the Dionysos really looks like in the flesh. It carries a proud name synonymous with beauty and for once a name doesn’t lie. The unit is sleek and made from thick milled aluminum stock front and back and thick panels elsewhere which merge together without visible fasteners. This is a fully tubed circuit with a 6C4P-EV (6Ц4П-В) rectifier, a SG15P (СГ15П) voltage stabilizer and a solitary twin triode 6N6P (6Н6П) as amplification element where each half powers one channel. Volume control is by transformer with switched secondaries similar to what’s in my Ayon Polaris III. [As owner of Bent Audio’s Tap X, I recognize the volume control and display to suggest that the TVC modules might be the very excellent John Chapman OEM units – Ed].

Unlike my Austrian linestage the Dionysos is very user friendly. Its display shows a numerical output setting for each channel, its i/o ports include balanced XLRs (de/resymmetrized by the transformers as the circuit itself isn’t balanced), a bypass and fixed out (for a subwoofer or headphone amp); there is polarity inversion which may be set/stored discretely for each input and more all stored in a micro processor. And unlike my large two-box affair, the Dionysos is small and in a single chassis. But not everything was peaches. After the first email confirmation I received a note to discuss how to properly match their preamp to a power amp. As it turns out, the Dionysos won’t complement all amps.

Thrax’s boss Rumen Todorov Atarski explained: "Our products are not universal and require some knowledge and experience. For example the amplification factor of the preamplifier is max 20dB (x 10) and available attenuation is 52dB over 24 steps. In combination with a classic 2V-out CD player and classic power amplifier with a rather high  0.5V input sensitivity, usable attenuation will be limited to 10 to 12 steps before things get too loud. Ideally the power amplifier has a far lower input sensitivity like some older 4.5V Krells. This is true also for our own amps. They require 4V to reach full power and present a rather low input impedance. It’s why anaemic preamps based on ICs for example may encounter problems driving them."

These are serious considerations unless one has a variable source like my trusted Ancient Audio Lektor Air whose output voltage I could easily trim to perfectly match the Dionysos particularly since the input sensitivity of my Tenor Audio 175S amplifier was still somewhat higher than ideal (1.3V on XLR, 1.5V on RCA). It’s thus important to acknowledge that the Dionysos has particular requirements and will fare best with power amps of low input sensitivity to fully exploit the low noise floor performance of its circuit.

Sound: I used the following discs for this review - Brenda Lee, Let Me Sing, Decca/Universal Music Japan, UCCC-9111, CD; David Sylvian, Secrets of the Beehive, Virgin/EMI Music Japan, VJCP-68879, CD; Jun Fukumachi, Jun Fukumachi At Steinway (Take 2), Lasting Impression Music, LIM DXD 038, silver CD; Tori Amos, Boys For Pele, EastWest/Warner Music, 80696-2, CD; Joe Pass, For Django, Pacific Jazz/EMI Music Japan, TOCJ-90027, HQCD; Tomasz Stańko Quartet, Lontano, ECM Records, ECM 1980, CD; Yoko Ono, Open Your Box, Astralwerks, ASW 88710, CCD;  Brian Eno, Another Green World, Virgin/Toshiba-EMI Limited, VJCP-68658, CD. 

For starters, the Bulgarian preamp turned out to be one of the very best of its kind I ever had through my system (and not only my system but for any absolute statements I refer only to my personal reference system in controlled listening conditions). It belonged into the same league as CAT’s SL1 Legend or Ayon Audio’s Polaris III. That already spoke for itself to set the tone.

The actual review sessions took longer than usual because I needed to employ a different methodology than I do with cheaper components or those who more easily reveal their personalities to make pegging their traits easier. For a trio of reviews I did for Audio, I exchanged my usual Polaris III for the Dionysos and over 4 weeks reviewed a lineup of D/A converters (Pro-Ject Box USB, Audinst USB DAC HUD-mx1, Musical Fidelity V-DAC, Arcam rDAC, Cambridge Audio DacMagic, Xindak DAC-5, Stello DA-100 Signature, Music Hall dac25.2, Wavelength Proton, Mytek Digital Stereo96 DA, Cary Audio Xciter DA, Benchmark DAC-1 PR, Naim DAC, CEC DA-1N for their 11/2010 issue); power amplifiers (Balanced Audio Technology VK-255SE, Mark Levinson No.532H, Pass Laboratories XA60.5 for their 12/2010 issue); and integrated amplifiers (Atoll IN400, Luxman L-507u, Mastersound Compact 845, Pathos Acoustics InpolRemix, QUAD II Classic Integrated for their January issue). This was a lot of work but successful. In all these reviews the Dionysos was the reference preamp. It never failed me. Then I listened to it exclusively in place of my Polaris III. 

Its tonal balance was splendid. The sound was very well balanced, better than most transistor preamplifiers which often imitate tubes like the Accuphase C-2810 or Luxman C-1000f—which are very good but I mentioned this trend in their reviews—and better also than the tube preamplifiers I listened to of late which sadly included my own reference. The sound of the Thrax is very open. It is not ‘electronic’ as today we perceive hi-end preamplifiers from 10 to 20 years ago. This is a much more immediate sound closer to what I hear from systems without a separate preamplifier as for example using the volume control integrated into my Ancient Audio player. Again this is a very open sound. The upper treble often gets problematic in lesser machines by becoming either glassy or annoying when the designers pursued the most open sound at any cost; or damped and warmed over when the same issues were to be exorcized by a slight withdrawal in this band. Here it was simply brilliant – precise and expressive without a trace of brightening or perceptible distortion (at least none I could identify).

This allowed the Dionysos to act very dynamic and expressive. To reiterate, expressiveness at this level of execution does not involve strategic coloration or irritation but simply shows events more verbatim like reality. This was aided by terrific dynamics. This overcomes the biggest issue of consumer hifi systems. It's not poor timbre or lack of resolution as much as it is a cardboardy lifeless, choked and muffled sound. Anyone who attends live concerts amplified or acoustic knows that live sound is completely different from what escapes loudspeakers. We must get used to the truth that we will never surpass reality. With the size of our listening rooms and the kind of electronics and loudspeakers we use, we simply cannot reproduce the intensity of the real thing. But we certainly cannot stop trying. We must try our best to fight our very real problems. Here the Dionysos shows how much can be done in that regard and how most other preamplifiers compress dynamics - to a bigger or lesser extent but they all do compress them. 

The Bulgarian eliminated this common ‘intermediary buffering’. When on For Django Joe Pass’ guitar entered the title track, it instantly electrified. This of course was assisted by a good pressing (here a HiQualityCD) and good recording in the first place but even so, with other preamplifiers the sound was less tacit and exciting. The Dionysos captured the shape of the guitar and contours of the percussion. I had the same impression with the opening cut of Tori Amos’ Boys For Pele which was recorded in one take, unplugged without overdubs using Leslie and Marshall amplifiers for the harpsichord and piano. Both instruments had a very large volume, more than I would have expected from guitar amplifiers. Their timbre was warm—that was set by the amps—but neither muddy nor turning the sound warm per se.

The attacks were starkly direct, vibrating with emotion and transmitting the recorded acoustics into my listening room. Part of the secret was higher than usual resolution and with it the ability to differentiate. Here my experience suggests that the only competition for the Dionysos is successful direct drive of variable source and power amp. Naturally my experience with statement preamps is limited. It presently for example doesn’t include pieces like the Soulution 720 or Kondo M-1000MkII which could reset the scales. But any assessment requires a base and mine is personal experience up to this date. Again, I’ve only encountered this level of performance before by eliminating a preamp. This suggests to me that the Dionysos indeed is a very special achievement of a preamp. It's not only incredibly resolved and open but achieves this degree of speed and directness without relinquishing its organic sound, stripping back harmonics or artificially illuminating the treble.

The opposite end of the spectrum was equally noteworthy. The bass was exceptionally potent, full and dynamic. It had impact when needed, was fleshy and when prompted by the recording almost not discernable. Usually bass occurs ‘somewhere in the background’ and midrange and treble are built atop it like a crouching tiger and hidden dragon. I previously only heard such good low bass in my home during the review of Krell’s EVO222+402. Then it required a complete set because the EVO preamp and power amp on their own were less impressive. Regardless the Dionysos repeated this experience. It fashioned brilliant moods that took the performances into a different dimension, seemingly away from my familiar surroundings. This most certainly wasn’t about any brutal bass pounding. Yes Yoko Ono’s club mixes from Open Your Box were great and had terrific foundation weight, energy and impact. But more important to me was how this springy yet powerful bass allowed vocals, trumpets, guitars and everything else to be built above it.

Take for example Jun Fukamachi At Steinway (Take 2) recorded in Direct-To-Disc technology (which is not about recording to a classic carrier like tape or hard disk but straight to the master that will press the record as the most direct way of coupling microphone to vinyl) or rather its digital representation, a CD issued by First Impression Music on silver. The owner of the original Direct-To-Disc mastered vinyl is Mr. Winston Ma, FIM’s owner. He transferred the signal from his turntable to a digital DXD recorder working at 24/352.8. The signal was then down-sampled to 16/44.1 with wonderful results.

To make it more interesting still, Mr. Ma recorded the same tracks twice, once using a van den Hul Colibri cartridge, once the FIM Black Ebony. The result is overwhelming! You can clearly hear how the FIM cartridge is superior, more direct, better saturated, with the upper piano registers more energetic and more natural and similar to what you hear standing a few meters from a Steinway. I know this well because I did arrange microphones for many pianos to appreciate how a strong attack on the keyboard can thrust us out of our seats. That of course depends on a pianist’s technique and abilities but if everything is there then the force of the instrument’s midrange and treble register is incredibly powerful.

This transpired with the FIM cartridge. But I really meant to describe the bass. I’ll just say then that the moment the diamond lowered into the groove (Mr. Winston Ma recorded everything without edits), I experienced it exactly as I would listening to a real expensive turntable. Of course you listen to the music and not to distortion and extra-musical effects but because I know this analogue sound by heart, I can evaluate it and transfer it later to the sound of a given musical number. This familiar needle contact was low, well damped and set aside from the sound of the piano as a well-known phenomenon that repeated itself lucidly now from a CD. It wouldn’t have come off this well without a perfect continuity of treble to midrange and the fleshiness of the bass.

There isn’t much I can say about the midrange. It was simply wonderful - smooth, full, precise, energetic and superior to any preamplifier I've heard to date. It will be easiest then to compare the Dionysos to others. This will also be an opportunity to point at aspects where other top-drawer preamps are still slightly better. The most obvious comparison was to my Polaris III. The Austrian preamplifier is a bit heavier and smoother in the midrange but not as open. Only by comparison to the Thrax could I now hear that its upper midrange is slightly warm and withdrawn to embellish vocals as just a bit prettier and warmer. Because the Ayon slightly emphasizes the midband—and again I could only detect this now—voices like Brenda Lee’s from the Let me Sing Decca mono and male vocals like David Sylvain’s from Secrets of The Beehive  seemed nicer and freer from irritating recording artefacts.

Yet the Dionysos showed them better still, arguably not smoothing them as much but together with the acoustics providing better body and shape. It was similar with Stańko’s trumpet on Lontano which seemed bigger with the Ayon but in fact lacked some information in the upper part of the spectrum and thus was less true. To keep things real, during normal listening these differences were not as pronounced as they might read but I couldn’t pass by them indifferently. 

The CAT SL1 Legend full-function preamplifier is sweeter, the Accuphase C-2810 warmer, the Luxman C-1000f warmer still, the Nagra PL-P quite ‘tubey’. If I sorted these contenders by timbre from warmest to most neutral, the lineup would work out to Luxman C-1000f → Nagra PL-P → Accuphase C-2810 → CAT SL1 Legend → Ayon Polaris III → Thrax Dionysos → Music First Audio Mk II Copper (TVC passive). Here proceeding from warmest to most neutral (or even slightly bright as in the Music First) equates to moving from the most ‘closed in’ to the most ‘open’ sound. As you can see, choosing between tube and transistor technologies has nothing to do with it. If I would have to identify one rationale for this sequence, I’d probably point at diminishing complexity. What could be simpler than a passive circuit with transformer attenuators like the Music First?

I’d rather refrain from such beliefs however and admit that I don’t know the real reason. The Ayon and Thrax are similarly simple/complex with transformer volume controls and single-stage voltage gain. It’s interesting too that this progression is about an increase in resolution. When we consider saturation and the tautness and fleshiness of the bass, the order reshuffles to Music First Audio Mk II Copper → Nagra PL-P → Luxman C-1000f → CAT SL1 Legend → Accuphase C-2810 → Thrax Dionysos → Ayon Polaris III. Regardless of the qualifiers I might use to reassemble this list, the Dionysos was the most versatile as though it sat at the center around which the dualities of warm/cold and light/heavy revolved.

Even so it won’t perform as good as the others in each and every instance. Its tremendous openness won’t suit systems with lit-up treble and specifically high presence region energy. Here the CAT would be the better integrator that brings everything together such that treble and bass considerations disappear into simply music. For very low powerful bass the Polaris is the choice. From amongst these only the Thrax maintained generally similar textures and amplitude but differentiated even better specific aspects of an upright or electric bass to make us momentarily forget that we're dealing with a recording.

The soundstage could perhaps have been shown a little better still yet I’m not 100% certain of this particular impression. It seemed that the Polaris III and CAT cast a more saturated denser soundstage. After switching to the Thrax everything seemed to be drawn to the virtual performers. This might have been superior focus in action but to me it appeared like a slight dimensional contraction. Whatever one might conclude here, the Dionysos is a fantastically made brilliantly featured one-box preamplifier that sounds as good and in some aspects better than far bigger twin-chassis efforts from firmly established companies. Bravo, bravo, bravo!!!

Description: 
The Dionysos preamplifier is the first product from the new Bulgarian Thrax Audio company who are based in their country’s capital of Sofia. It is a linestage preamplifier fully realized with tubes. Rectification is handled by a 6C4P-EV (6Ц4П-В), voltage is stabilized by constant current sources feeding a shunt regulator with a SG15P (СГ15П) reference and voltage amplification is via a single 6N6P (6Н6П) double triode. All tubes are NOS Russian issue. Interestingly the amplification tube is the only active element in the signal path. One half works in the right, the other in the left channel. This single-stage topology recalls the more expensive Conrad-Johnson preamplifiers or my Ayon. This also means that the unit inverts absolute phase.

The enclosure is executed brilliantly from thick aluminium panels bolted together without visible fasteners and a barely discernable seam. The front is carved from very thick aluminum stock to gracefully flow around the control elements. The most important of these is the big cenral volume control and two green LED displays hidden behind acrylic windows which show the volume for each channel. Balance can be set from the remote control or small buttons on the fascia. The remote is very chic black anodized metal with chromed ends and  easy to operate. It controls volume, balance, inputs, absolute phase for each input, mute and power. All these functions are also duplicated on the front panel. Unfortunately the knobs and indicators are not identified which seems a bit too much of an extravagance even if it helps to keep the fascia clean [they are properly coded/named on the belly of the machine).

Looking from the left we start with the power switch with an indicator LED that changes from red to green after the unit is powered up. The next button activates the fixed output. To the right we have two buttons to select the active input and between them a button for changing absolute phase. Its activation is indicated by the LED of the chosen input. It changes from green to orange (unfortunately the LEDs are not described so you have to guess which input is active). The back is as solid a slab of milled metal as the front, not very typical for the hi-end. Here we get wonderful RCA and XLR sockets. Although the preamplifier is not balanced, the XLR inputs and outputs run desymmetrizing and symmetrizing transformers to accommodate balanced sources and amplifiers. 

There are four unbalanced inputs and two balanced ones. One of the inputs can be set to bypass for home cinema systems to become a loop-thru. There are also rec outputs, switches to cut signal ground from chassis ground and four outputs – two RCA, two XLR. Interestingly the recording output is buffered by a floating amplifier with a transformer input. Thus its usage does not influence the sound quality. In a separately milled recess sits the IEC socket, a mechanical power switch and a level set button. This can be used to set the level of any chosen input and place it in bypass mode. This input's LED will then turn red. The voltage level is set in internal memory and won’t default with power-down. Unity gain equates to 24 on the display. 

To get inside this chassis we have to remove the carbon-impregnated plastic footers. After unbolting the bottom plate, we get access to the screws fixing the top cover. We immediately see a combination of splendid engineering—thought-through mechanics and topology—and NOS parts combining with modern parts. It’s apparent that each element was considered for its sonic contributions first and on price a faint second. After the Absolutor preamp I once again stared at Soviet parts so disdained not so very long ago but returning to active duty. Of course here they weren’t exclusive but included tubes (I couldn’t stop thinking that my Lektor Air player too uses Russian 6H30), resistors and mighty oil capacitors in the power supply to see army surplus put to good use again. 

What first catches the eye is the fabulous mechanical structure. The PCB with the amplification section and power supply is bolted to two blue-anodized aluminium bars which themselves are not bolted to the bottom plate but the chassis cheeks. The entire power supply also mounts there with a nice big transformer, NOS oil capacitors from the USSR and a very big Lundahl choke. To the other side panel bolt two big Japanese Hashimoto Electric output transformers and the volume control and input decoupling transformers enclosed in catchy solid metal cans. From below we can spot a few integrated stabilizers and many transistors working in the solid-state voltage regulator circuits. All are bolted to a long big heat sink located on the other side of the PCB.

The inputs are soldered into small oblong channel-specific PCBs with relays. From there the signal goes to the Permalloy transformers from SLK Transformer and then extravagant Oyaide cables—high quality PCOCC-A wires rarely seen —connect to the main board. The internal heat sink divides the PCB in two parts, power supply and amplification circuit. In the latter we only have one 6N6P (6Н6П) twin triode. Next to it we see a few high-quality passive Wima caps, precision resistors and active OPA656 op amps. To the side there is an additional PCB with two rows of relays to key the individual TVC secondaries. The relays are controlled by integrated switches. On the other side of the heat sink divider sits the power supply with the 6C4P-EV (6Ц4П-В) tube rectifier and a voltage stabilizer using the SG15P (СГ15П). On the tubes we can see ferrite muffs for EMI shielding. The heater circuits are rectified by solid-state bridges separately for the power supply and amplification tubes. This is fantastic brilliant execution!

…….Wojciech Pacuła

Thrax Orpheus Phono Preamplifier From Bulgaria Looks to be a Sonic Winner
Michael Fremer - May 2013

Thrax has yet to make major inroads in the American market but that will surely change as its products become better known. At least that's my assessment based upon what I saw and heard in Munich.

The products look beautiful and the engineering is impressive based upon my conversations with the owner/designer Rumen Todorov Atarski. A nasty rumor floated around last year claiming that Thrax designs and builds Ypsilon's products. I don't know who started such a rumor but they should cut it out!

In fact Mr. Atarski and Ypsilon's Demetris Backlavas are friends but they are also competitors manufacturing very different products, though the Orpheus, like the Ypslion VPS-100 phono preamplifier features zero feedback passive LCR phono equalization.

The Orpheus's input stage is a low noise D3A German Post triode tube that produces gain and the output impedance to drive the LCR RIAA equalization that uses high precision custom made Sowter coils wound with Cardas wire and Jupiter BeeWax impregnated paper capacitors.

The next stage uses another low noise tube, this one a Russian triode similar to a WE417 loaded by a Hashimoto transformer to produce necessary level and isolation from the next stages.

But enough circuit description in a show report. The rest will have to wait for a review. If anything is a "Ypsilon competitor (or killer)" this might be it. The power supply is equally impressive. The Orpheus has two RCA and one balanced XLR input, with ground planes switched between inputs to avoid ground loops and induced ground noises.

The Thrax line includes a remote controlled preamplifier, a directly heated triode power amplifier, a Class A Hybrid tube/fet amplifier and a DAC that incorporates a DSP controlled discrete resistor ladder DAC built for Thrax by MSB.

In its brochure (a close second place to Sperling for sumptuous photography) Thrax pays homage to Shisido San's Wavac and Kondo San's Audio Note Japan designs. The International aspect of Thrax's componentry is among its many attractions.

........Michael Fremer - May 2013

Jason's Adventures Continue on Day 2 at MHES 2016
Jason Victor Serinus 

Ah yes. Through the audio jungle I thrashed, through sound both thrilling and threadbare, until, having totally exhausted the alliteration resources of my thoroughly thumbed thesaurus, I alighted upon the thoroughfare of Thrax. Once there, I threw all literary pretence aside, and thrillingly cried, "Thanks be to Thrax!"

And with this borderline hysterical paragraph behind me, I solemnly pledge to never again abandon critical impartiality in order to indulge in the mad plunge into holographic hyperbole!

Over it I may be. But what I'm not over is how good this room, assembled by HiFi Imports, sounded. Perhaps in part due to canny speaker positioning, the Thrax Lira 77lb. loudspeakers threw an astoundingly large soundstage that was far larger than any two-way stand mount of this size has any right to create. The presentation had lots of atmosphere, with a beautiful midrange. Equally important, the system could perfectly spotlight instrumental solos in a most musical manner. (Note: When I first encountered these speakers in Newport Beach last June, they were not broken in. The set-up sounded considerably better this time around.)

First up, on LP, were the very space music "Intro" and "Numb" tracks from Sam Brookes' Kairos. Everything sounded just as it should, which means perfectly musical and all-enveloping. I had never heard the music before, but it sounded so fine that it felt like just what the artist hoped we would hear.

Then came "St. James Infirmary," with cymbals and horns sounding drop-dead gorgeous. And I wasn't the only one who marveled. Two dealers who had chosen to sit RMAF out this time around were seated behind me, enjoying the music just as much as I did.

Playing while I was present, in addition to the loudspeakers: Thrax Dionysos linestage preamplifier, Thrax Orpheus phono preamplifier with LCR RIAA equaliser, Thrax Teres Hybrid power amplifier, Dohmann Helix 1 turntable with new Schroder CB tonearm.

Leaving with regret: yours truly, Jason Victor Serinus 

Videos

Thrax Factory Part 1