DarTZeel CTH8550 2x220w dual/mono Integrated amplifier

DZ 02 IA CTH
NZ$ 41,995.00 ea (incl. GST)
DarTZeel

Passion for Sound "The human being himself, to the extent that he makes sound use of his senses, is the most exact physical apparatus that can exist."

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The CTH-8550 embodies everything that an integrated amplifier should be: Compact, practical, versatile, musical, elegant and powerful

Until recently, integrated amplifiers only achieved distinction despite trade-offs in design. Most integrated amplifiers have been built under budget and pricing constraints that leave little room for high performance.

That's why darTZeel is proud to present the CTH-8550, the first integrated amplifier without compromise.

With its dual-mono architecture, 50-ohm Zeel inputs, optional high-quality phono stages and remarkable versatility, the darTZeel CTH-8550 is the integrated amplifier of choice for audio enthusiasts.

CTH-8550: at the heart of the music
With up to nine analogue inputs for RCA, XLR and Zeel 50-ohm cables, all sources including turntables are accommodated.

Boasting ample power reserve capacity, a wide range of functional features and unrivalled ease of use, the CTH-8550 is the most complete integrated amplifier in its field.

Sound at your fingertips
The remote control is machined and milled from pure aluminium ingot, offering premium build quality and technology to enhance the user experience.

Dual-mono design
A look inside the darTZeel CTH-8550 reveals a dual-mono design, including separate channel windings from both toroidal transformers.
Its sound image is revealed in an exceptionally pure expression.

Style and functional features
The darTZeel CTH-8550 is equipped with a plasma control panel, offering excellent contrast when viewed from any angle. A range of menus allows you to individually configure all settings for each input source.

Ease of use
Volume control is handled by an optical encoder notched magnetically, for unrivalled touch and precision. Round steel buttons add to the unit's appeal.

Features

Specifications

Reviews

Videos

Features

Dual-mono design
A look inside the darTZeel CTH-8550 reveals a dual-mono design, including separate channel windings from both toroidal transformers.

Specifications

Nominal Output Power
200 watts RMS (230 watts peak) @ 8 ohms
330 watts RMS (360 watts peak) @ 4 ohms
400 watts RMS (500 watts peak) @ 2 ohms (software limited)
Line Gain
0 dB nominal, up to + 12 dB (+22 dB custom)
Power Stage Gain
26 dB @ 8 ohms
Analog Input Impedances
1 x Zeel BNC 50 ohms
1 x RCA line > 30 kohms
1 x XLR > 30 kohms

Optional Phonos:
Phono MM = 47 kohms. Neumann RIAA 4th pole included
Phono MC = 1 kohms. Neumann RIAA 4th pole included
Line Output impedances
RCA = 75 ohms, darT BNC = 50 ohms
Speaker Output Impedance
< 0.33 ohms from 20 Hz to 20 kHz (measured under 8 ohms)
Frequency Response
2 Hz - 200 kHz, +0, -3 dB
Rise Time
< 0.8 µs
Slew Rate
> 88 V/µs, peak-peak
DC Output Voltage
< ± 15 mV max
Total Harmonic Distortion (THD)
< 1 % from 7 Hz to 77 kHz within the output dynamic range
Temporal Distortion
None, at any level and load, as specified above
Crosstalk
< - 90 dB from 20Hz to 20kHz
Signal to noise ratio
> 115 dB (A) @ nominal power
Power consumption
3 watts Standby, 40 watts @ idle, 1000 watts @ maximum output power
Size in mm
440 x 350 x 170 (WxDxH). Total deep with handles : 415mm
Size in inches
17.32 x 13.78 x 6.7 (WxDxH). Total deep with handles : 16.4 inches.
Net weight
28 kg

Reviews

No matter what your taste in music is, I guarantee the darTZeel can not only handle it, it will take you to a place you haven’t been and that’s what it’s all about
Jeff Dorgay - ToneAudio

If you’re ready to get off the merry-go-round and just enjoy music, and you’d like to be set free of component and cable matching, the darTZeel CTH-8550 will take you to Nirvana. It offers a level of musicality that few amplifiers I’ve heard possess. Add your favorite source or two, a great pair of speakers and call it a day.

Add the darTZeel to the list of the rare few solid-state amplifiers that are so grain free, you just dig the music and don’t even stop to think whether you are listening to tubes or transistors. And it offers everything: staggering dynamics, spot-on tonality and a gigantic three-dimensional soundstage. The detail that the CTH-8550 provides without ever being harsh is intoxicating.

Young’s voice just floated in front of the soundstage, with the rest of the backing instruments all having a specific space instead of falling into the grunge, as it would in a mediocre recording.

R E V I E W

One thing I didn’t experience a whole lot during my recent trip to Switzerland was an overall sense of humor. The trains ran on time, all the outlets in my hotel room worked perfectly and there was always plenty of hot water. But I never got a feeling of lightness, even at the Montreux Jazz Festival. The Swiss take most of what they do seriously, and what they take seriously, they do fantastically.

But after living for some time with the darTZeel CTH-8550 integrated amplifier, I get the feeling that principal designer Herve Deletraz has a good sense of humor. Not for putting a US$20,300 price tag on the CTH-855; he’s dead serious about that. Upon unpacking the CTH-8550, with its bright-gold (not subdued Conrad Johnson champagne, but bright gold) and bright-red case, I took a bit of pause. After six months with the amp, I decided that if I were buying one, I’d go for the red and gold instead of the more subdued all-black model. It fits.

The fun continues as you take a closer look at the front panel and notice that the volume control is labeled “Pleasure Control,” with an arrow going clockwise indicating “more” and counterclockwise indicating “less.” Perhaps there are some Swiss guys who like to rock the house after all.

Before the Fun Can Begin, Configuration is Necessary

The CTH-8550 has over 50 different menu options hiding behind that amber LED panel, so I suggest reading the manual very carefully. Before you can configure this amplifier for your use, you will need to locate and install the USB key.

It’s a very tasteful brushed aluminum USB drive with the darTZeel logo etched on the outside and attached to a small chain. You will need an activation code from your dealer that once downloaded to the USB key stores all of your amplifiers parameters, allowing your amplifier to escape “demo” mode. Without the USB key, the amplifier shuts itself off. A rather nice anti-theft touch since you can only reactivate the amplifier if you are the original owner.

You can configure almost every parameter of the CTH-8550, from the maximum volume level addressable to when you’d like it to turn on and off throughout the day. Like BAT and McIntosh you can re-label the inputs from “input 1” to “CD player,” “Turntable,” “Tuner”, etc. This makes things a little easier when family members use the system. Don’t Try This at Home

My listening began with the MartinLogan CLX’s by giving that Pleasure Control a big spin after queuing up a dozen of my favorite Van Halen tracks on the Sooloos music server. No FTC standard preconditioning here, folks. Unfortunately, the CTH-8550 was not up to this punishment, and just as I was getting into a serious air-guitar session during the lead break of “Atomic Punk,” the fun came to a dark halt.

Ever destroy the transmission in Dad’s car doing neutral drops when you were supposed to be running errands for your Mom and coming straight home from the store? That’s the same feeling you get when you fear that you’ve just melted down someone else’s US$20,000 amplifier.

Fortunately, after about a 20-minute cool down and a quick speaker swap, the CTH-8550 was good as new. In typical Bart Simpson fashion, I had to try it again. Swapping the CLX’s for the Verity Audio Sarastro II’s seemed to sure the problems. So as much as I love the CTH-8550, it’s not a match for MartinLogan speakers, especially if you like to rock out in a major fashion. Though the CTH-8550 ran very warm, it did not shut down again, regardless of volume level with the rest of the speakers I had at my disposal.

I’m guessing it’s another example of Herve’s sense of humor because the manual claims that this amplifier “runs very cool, saving on your electric bill.” No way. This amplifier runs warm, bordering on hot, which makes me wonder if it doesn’t spend a lot of time running in Class-A mode or very close to it. But the world’s going to end in 2012 anyway so I’m more than happy to increase my carbon footprint a few more millimeters for sound this good.

Breaking It Down
Vacuum tubes are tons of fun until they don’t work right or you have to pay the NOS tube bandits a ridiculous sum of money to retube your precious. That’s when the fun ends. So in Swiss fashion, let’s get serious for a minute and do a little cost analysis, shall we?

While I’m sure some of you completely freaked out when I mentioned the US$20,300 price tag of the CTH-8550 at the beginning of the review, where does your money go? When you break it down, the CTH-8550 isn’t that scary after all. My neighbor just dropped US$30,000 on a John Deere tractor to cut his grass, and how much fun is that? Not nearly as much fun as listening to this Swiss masterpiece from darTZeel.

If we take the $20,300 price of the CTH-8550 and subtract the cost of a pair of suitable power cords, say US$750 each, and two pairs of somewhat upscale interconnects at US$1,000 each from the purchase price, it drops down to US$17,500. Ok, so that’s still not bargain-basement pricing, but remember, the CTH-8550 has a full-function preamplifier, 220-watt-per-channel power amplifier and a damn good phono preamplifier all on one chassis. So at that rate, if we look at the CTH-8550 as a US$4,000 phono preamplifier, US$6,000 preamplifier and a US$7,500 power amplifier, it’s not crazy money anymore.

Now, let’s say you keep the CTH-8550 for five or six years. That means at least one retube of your preamplifier and maybe twice for your power amplifier. If you’ve got a pair of big tube monoblocks that use eight output tubes per side, that’s 16 (count em’) tubes to replace. Even with so-so tubes, we’re talking about US$1,600. And if you want some expensive NOS versions or the boutique EAT KT-88’s, you’re staring at US$5,000 worth of tubes. That darTZeel is now looking like a real bargain, eh?

Who needs tubes when solid-state sounds this glorious?

Add the darTZeel to the list of the rare few solid-state amplifiers that are so grain free, you just dig the music and don’t even stop to think whether you are listening to tubes or transistors. And it offers everything: staggering dynamics, spot-on tonality and a gigantic three-dimensional soundstage. The detail that the CTH-8550 provides without ever being harsh is intoxicating.

This amplifier never failed to catch me off guard, even when listening to less-than-outstanding recordings. I’ve heard Tommy James’ “Do Something to Me” a zillion times over the past 40 years, but with the combination of the darTZeel and the GamuT S-7’s, there were about three more layers of overdubs that I’ve never heard before. It’s even better with great recordings. Spinning Swim from The Whispertown 2000 had an overwhelmingly huge soundstage. Listening to my favorite female vocalist of the year, Anya Garbarek’s Smiling and Waving was spooky in a David Lynch movie kind of a way. All of the Frank Zappa records I played had the same effect; there were so many little musical details floating around the the room, at times it was hallucinogenic and that’s a ton of fun in my book.

Great Phono
Quite a few of the very expensive preamplifiers that I’ve auditioned in the past couple of years that include an on-board phono preamplifier, the darTZeel is only one to which I’ve listened that actually has a phono stage worthy of the amplifier it’s built into, not just an afterthought.

For the duration of the review, I used the Dynavector XV-1s mounted on a Raven Two with SME iV.Vi arm and was very pleased with the results, though I usually load the Dynavector at about 500 ohms in my reference system. This leads me to the only major complaint I have with this amplifier: I was hoping that somewhere in that long list of menu items, there would be a way to change phono loading, but no such luck.
This means that making the CTH-8550 part of a system that includes analog playback will require a cartridge that will work well with 1,000 ohm loading.

Again, I would like to stress that this is not an “add-on” phono stage and I would compare this one to other units I’ve heard in the US$3,000 - US$4,000 range in terms of dynamics, tonal accuracy and most of all, quiet. The darTZeel has one of the quietest phono stages I’ve had the pleasure of hearing.
In many ways, it reminds me a lot of the battery-powered Nagra FFF that we reviewed earlier in the year. Another Swiss masterpiece. Hmmmm.

At the very end of this review, the four-LP Neil Young box set arrived, and this was the final bookend on the darTZeel’s phono stage. These records have super-quiet surfaces that only played to the strength of the Dynavector/darTZeel combination. These records are some of the best analog I’ve heard this year, so they make a great demo discs. This was probably the first time I’ve listened to Harvest all the way through in 30 years and it was outstanding. Young’s voice just floated in front of the soundstage, with the rest of the backing instruments all having a specific space instead of falling into the grunge, as it would in a mediocre recording.

No matter what your taste in music is, I guarantee the darTZeel can not only handle it, it will take you to a place you haven’t been and that’s what it’s all about when someone is asking you to write a US$20,000 check. If you are an audiophile that changes electronics like underwear, spending time with the darTZeel will probably be a costly stop on the path because you always lose money going from new to used. But if you’d like something to live with long term, you can finally stop horse trading with one of these.

Conclusion
If you’re ready to get off the merry-go-round and just enjoy music, and you’d like to be set free of component and cable matching, the darTZeel CTH-8550 will take you to Nirvana. It offers a level of musicality that few amplifiers I’ve heard possess. Add your favorite source or two, a great pair of speakers and call it a day.

Get off the Merry-go-round!

If you are ready to get off the merry-go-round and just enjoy music, and you'd like to be set free of component and cable matching, the darTZeel CTH-8550 integrated amplifier will take you th Nirvana. It offers a level of musicality that few amplifiers I've heard posess. Add your favourite source or two, a great pair of speakers and call it a day.

TAS @ RMAF - Johnathan Valin
TAS @ RMAF - Johnathan Valin

Jonathan Tinn’s $27k Evolution Acoustics MMMiniTwo is essentially a two-way MMMiniOne on top of a MMMiniSub, with the MiniOne ceramic mid/woof and ribbon tweeter housed in a beautifully finished transmission-line enclosure and the MiniSub ceramic-oval subwoofer in an equally beautifully finished acoustic-suspension enclosure. The speaker was driven by DartZeel electronics. The sound was downright lovely on a Mozart Violin Concerto (played back on a reel-to-reel tape deck, by the bye), with beautiful timbre, nice delicacy of texture, and none of the heaviness and darkness that have weighted down previous EA demos.......overall this was the best showing of an Evolution Acoustics speaker I’ve experienced thus far at a trade show. One of the better sounds at RMAF

Jonathan Tinn’s $27k Evolution Acoustics MMMiniTwo is essentially a two-way MMMiniOne on top of a MMMiniSub, with the MiniOne ceramic mid/woof and ribbon tweeter housed in a beautifully finished transmission-line enclosure and the MiniSub ceramic-oval subwoofer in an equally beautifully finished acoustic-suspension enclosure. The speaker was driven by DartZeel electronics. The sound was downright lovely on a Mozart Violin Concerto (played back on a reel-to-reel tape deck, by the bye), with beautiful timbre, nice delicacy of texture, and none of the heaviness and darkness that have weighted down previous EA demos.......overall this was the best showing of an Evolution Acoustics speaker I’ve experienced thus far at a trade show. One of the better sounds at RMAF

But love it I did, using it made me feel good, which is what that "pride of ownership" thing is all about.
Wes Phillips

The CTH-8550. It drove the Thiel CS3.7 and YG Anat Reference II Pro speakers as easily as it did the benign Klipsch Palladium 39Fs.

Harmonic overtones sparkled and lingered—the amp was very quiet, so I heard deep into what, with other components, would have been the background. Haden's bass, too, had convincing slam...

That sense of scale and deep immersion in the acoustic was also evident in "Linden Lea,"

The singers are placed deep in the acoustic,,, very deep.

Then there was the setting of Loreena McKennitt's "Tango to Evora," which again adds the hand drum plus a guitar—and sets soprano Melanie Anderson against a gentle wash of harmonies. It's a quiet song, and a very passionate one. The CTH-8550 preserved all of that while giving me intense goose bumps.

I was floored by the CTH-8550's quality, performance, and convenience. It is a dream component.

 

 

darTZeel CTH-8550 integrated amplifier review:

As the 2009 Consumer Electronics Show neared its end, I wandered into Blue Light Audio's room, which was dominated by the innards of darTZeel's new NHB-458 monoblocks—think of a 3D "exploded" diagram and you'll be on target. So impressive was that display of brute engineering that I almost didn't notice the amplifier that was actually making the music: the CTH-8550 integrated (US$20,300).

Yes, you read correctly: US$20,300 for an integrated amplifier. That's an order of magnitude greater than the typical integrated. Granted, you get a moving-coil input, and it's built in Switzerland to Swiss standards, and it cranks out 220Wpc into 8 ohms or 350Wpc into 4 ohms, and it's endlessly user-configurable—but Criminy, that's a lot of simoleons.

DarTZeel can rightfully argue that each of its products is meticulously engineered by Hervé Delétraz, which means that its products employ unique technologies. And, far from benefiting from any economies of scale, darTZeel components are about one step short of bespoke—they're made by hand, and mighty close to order. But none of that will matter if you can't get past the sticker shock.

Men are only as good as their technical development allows them to be
If you can get over the shock, however, the CTH-8550 is packed with interesting technologies—such as its optical Pleasure Control (as Delétraz calls the loudness control), with a range of from Less to More. Manufactured and customized for darTZeel by Elma, it's the most responsive knob I've ever fondled. Its tactile feedback was, well, fun—I'll confess to twirling it a few times just for fun as I murmured, "Come in, Rangoon."

Then there's the CTH-8550's display screen, which, along with its CPU, lets you set virtually any parameter to your preference—and includes both a clock and a function that automatically powers the amplifier on or off at a set time. My first thought regarding this "alarm," as darTZeel calls it, was to laugh—but then I imagined a scenario in which my CTH-8550 powered itself on every evening half an hour before I got home from work, and was ready to rock my world as soon as my butt hit the comfy chair. Of course, the problem with that fantasy is that first I'd need a day job—although if I did, perhaps I wouldn't find the price so daunting.

The CTH-8550 uses a large toroidal transformer for its output stage and a smaller one for low-level signals. (If you use it only as a preamplifier, you can turn off the big toroid via that nifty display.) Delétraz has designed an output stage based on paralleled transistors and short signal paths; he doesn't say much about it, except that it is supposed to run cool—oh yeah, and that it sounds good.

The CTH-8550 has two sets of unbalanced RCA outputs, one following the volume control so that the amp can be used as a preamp, a "darT" output (50 ohm BNC), two "Zeel" inputs (ditto), four unbalanced RCA inputs, plus two more pairs marked MM and MC (MM is optional; an MC module, with user-adjustable gain, comes standard in the US), and a pair of balanced XLR inputs. The speaker terminals are substantial—and, even better, they open wide enough to accept thick spades. An IEC mains jack and two USB inputs complete the complement of connectors.

Two USB inputs—whatever for? The CTH-8550 comes with a USB flash drive, which arrives blank; you must register your CTH-8550 online to receive a compressed folder with a .dtz extension. Transfer the file to the USB stick and plug it into a USB slot on the CTH-8550, at which point you upload the latest upgrades to the unit's firmware, as well as your activation code. Skip that last step and your US$20,300 component will work for a mere 15 minutes every time you power it on, then shut itself off.....

As with other darTZeel products, the cosmetic package of the CTH-8550 is unique. My sample had darTZeel's usual livery of gold-anodized faceplate with burgundy chassis (an all-black model is also offered). While the CTH-8550's fit'n'finish and materials are impeccable, it looks less styled than engineered. In a channel milled into its thick faceplate are 11 LEDs (one per source and one each for the left and right channels) and eight pressure-actuated switches (Menu, Time, Light, Name, Mute, Mono, Balance, Power). There are two massive handles, and another pair on the back, which is good—the li'l sucker weighs 62 lbs. Between the front handles are the optical control and the display. Most of the CTH-8550's bling is on the inside.

Four legs good, two legs bad
For all of the CTH-8550's customization options, I found it simple to use. Most of its settings are set-and-forget. Its heatsinks are mounted under its vented casing, so it can be placed just about anywhere that can support its mass and allows adequate ventilation. For all the pleasure I got spinning the Pleasure Control, in daily use I used the remote control almost exclusively. While the display is easy to use up close, much of its information is in a font too small to be seen from across the room, so I opted for its Auto Off feature.

A major fault of conventional integrated amplifiers is lack of get-up-and-go. Sure, lots of them have "rated" outputs of 150–200Wpc, but hook 'em up to a difficult load and they wimp out. Not, apparently, the CTH-8550. It drove the Thiel CS3.7 and YG Anat Reference II Pro speakers as easily as it did the benign Klipsch Palladium 39Fs.

Progress is not an illusion
Sonically, the CTH-8550 was very much a twin of darTZeel's NHB-108 power amp: fast, dynamic, and detailed. On "Skeleton," from the Ginger Baker Trio's Falling Off the Roof (CD, Atlantic 82900-2), the CTH-8550 balanced the power of Charlie Haden's bass against Baker's controlled marching beat (is there such a thing as a contemplative march?)—Haden and Baker seemed to inhabit separate acoustics, with Baker in a larger, more reverberant room. Bill Frisell's guitar is the real star here, and the darTZeel let it "jump." Harmonic overtones sparkled and lingered—the amp was very quiet, so I heard deep into what, with other components, would have been the background. Haden's bass, too, had convincing slam—even though it was close-miked, Frisell's guitar was not given remotely similar heft.

That sense of scale and deep immersion in the acoustic was also evident in "Linden Lea," from the all-women chamber vocal group Angelica's The Beautiful Treasure: Songs from Near & Far (CD, Angelica). Recorded in the South Presbyterian Church at Dobbs Ferry, New York, by Len Moskowitz, the singers are placed deep in the acoustic—and through the CTH-8550, very deep. On "Over the Hills," the chorus is joined by hurdy-gurdy and hand drums, and the differences in scale were extremely well delineated by the darTZeel. Then there was the setting of Loreena McKennitt's "Tango to Evora," which again adds the hand drum plus a guitar—and sets soprano Melanie Anderson against a gentle wash of harmonies. It's a quiet song, and a very passionate one. The CTH-8550 preserved all of that while giving me intense goose bumps. Analytic it may be, but cold? Not hardly! (If you're a fan of John Atkinson's recordings of Cantus, you should just go ahead and buy Len Moskowitz's Angelica discs—they're fabulous in completely different registers.)

Guitarist David Russell's For David: Music Written for David Russell (CD, Telarc CD-80707), recorded in Telarc International's preferred venue for Russell, the Peggy and Owen Gordon Center for the Performing Arts in Owings Mills, Maryland, has a completely different sonic perspective. Here the guitar is recorded relatively closely, but there's still plenty of acoustic support. Producer Elaine Martone and engineer Thomas Knab chose that perspective wisely, since these adventurous modern works get fast and furious—and, at times, in your face. A case in point is Benjamin Verdery's Now and Ever II, which uses an alternate tuning (D, G, A, A-sharp, E) and opens in an explosion of chords, followed by a flurry of measures in 7/8, 6/8, and 5/8. It's devilishly complex, for all that Russell aces it, and the CTH-8550 sorted it out a treat—yes, the guitar was very up-front, but the hall sound informed and supported the fundamental tones without blurring them.

Spoon's "Don't You Evah," from Ga Ga Ga Ga Ga (CD, Merge MRG295), had impact a-plenty through the darTZeel. The bouncy bass-and-drum intro had impact and momentum—the song is virtually constructed as it rolls along ("Record that, Jim"), and by the time the vocals enter, guitars, maracas, and hand-claps have appeared. The power and crunch of Jim Eno's drums were particularly evident through the CTH-8550. It rawked. "The Ghost of You Lingers" features a completely different soundscape—layered and complex, with instruments like shakuhachi and sound effects—but it, too, was beautifully parsed by the CTH-8550. The darTZeel had me going back again and again for more—and more is what I always got.

Happiness can exist only in acceptance
We proponents of the High End are fond of citing "intangibles" such as pride of ownership and the satisfaction of knowing you own The Best. These are real and quite considerable—and the darTZeel CTH-8550 delivers them in spades. It is a genre-defining product: a contender for The Best by anyone's definition of the term.

From an engineering perspective, the CTH-8550 is very cannily sorted out. It won't set the thermostat for you, or cook your bacon and eggs, but it can be programmed to do just about anything you could desire from an audio component. And it is hand-built in Switzerland, which means it represents the pinnacle of construction. But all of that comes at a price: US$20,300.

I don't think for a moment that darTZeel is price-gouging. All of the metalwork and custom componentry, not to mention that hand-hewn Swiss precision, undoubtedly does cost a lot....

But love it I did. Using it made me feel good, which is what that "pride of ownership" thing is all about. It was about as transparent a window onto recordings as I have ever heard. And because darTZeel products are a little quirky—a Control for dialing in Less or More Pleasure, ho-ho—they reflect the personality of their creator, Hervé Delétraz, which made me feel a personal connection to the manufacturer. All of those elements do create added values—albeit values that are completely subjective and personal.

I was floored by the CTH-8550's quality, performance, and convenience. It is a dream component. Unfortunately, dreaming is about as close as this humble scribe can come to owning one.

The amp makes light work of the waves of instrumentation and delivers it all with a strong propulsive quality that really gets the listener involved.
Stunning build and finish
agility and clarity
composure when pushed
flexible
refinement
Never has the colour of a hi-fi product drawn so much comment from our testing team.
 
Dartzeel's trademark combination of a gold front panel and red casework just didn't work for most of our reviewers, but it may work for you. If the combination doesn't suit, there's always the more conventional all-black version as an alternative.
 
What does this significant investment buy you? Immaculate build, for starters. Dartzeel is a Swiss company and all the stereotypes about Swiss engineering hold true. The CTH-8550 is beautifully made, from its intricately machined volume control to the solid casing.
 
Top-quality components

Internally, it's as we'd expect: carefully considered circuit layouts, bulky dedicated power supplies and top-quality components.
 
The result is a 220w per channel integrated that raises its power output to 330w as impedance halves. That kind of power is enough to drive most speakers to high levels, even in larger rooms, although it's only fair to point out that there are plenty of amps that produce more power at a fraction of the price.
 
As standard, the Dartzeel comes as a line level only unit, with four RCA inputs and a single balanced XLR pair. The amp has a further two connections referred to as Zeel 1 and Zeel 2, though we've never come across a source component with only BNC outputs.
 
To this range of inputs you can add optional moving magnet and moving coil phono boards. 
 
Incredibly adaptable unit

This integrated is massively configurable, from trimming input levels, to disabling the power amplifier stage to transform it into a dedicated preamp.
 
There's even an internal timer to switch the amp out of standby just to make sure its circuitry is nice and toasty before listening starts.
 
The amplifier is supplied with two nicely weighted remote handsets: one is comprehensive, covering all the amp's features, while the other is a simple device for altering volume level.
 
In use the CTH-8550 is amazingly crisp and precise-sounding. There's loads of fine detail and that makes it easy to hear deep into the mix of music such as Schubert's Symphony No.9.
 
Gets the listener involved
The amp makes light work of the waves of instrumentation and delivers it all with a strong propulsive quality that really gets the listener involved.
 
Tonally, Dartzeel gets it right. Despite all the precision there's not a hint of clinical here: its sonic presentation is sweet without softness, and full-bodied without overt richness. Instruments lack nothing when it comes to texture or solidity.
 
There's also enough agility and snap to work well with hard-charging music such as Florence and the Machine's Lungs.
 
You can add impressive composure during complex recordings and at high volumes to the plus column too, as well as a well-focused soundstage.
 
Its power output is healthy enough, but the amp never quite manages to pound out bass lines or deliver midrange slam with the utmost determination (might depend on the speakers somewhat)
 
Remember this is no off-the-shelf product. It's pretty much built to order, and built to the highest standards. That in itself explains part of the outlay.

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