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DarTZeel CTH-8550 Integrated Amplifier

DarTZeel CTH-8550 Integrated Amplifier

Every musician, regardless of their chosen instrument, is looking for their voice and not just their own sound. When I listen to a great piano player, saxophonist or violinist, I am always aware of the vocal narrative that lies behind what they are saying through the instrument. That is what draws me to their playing and has probably been indirectly responsible for my interest in home audio for years. When you think about serious musicians and why you prefer some over others, I think it’s about their supreme ability to make the instrument talk to the listener through the music. Through technique, physical ability, good ear and taste, they speak to us through our home systems and hopefully, we respond to their message and narrative.

Interestingly enough, Hervé Delétraz refers to his amplifiers as instruments. After having spent some time listening to his CTH-8550 Mark II integrated amplifier, I completely understand why. I reviewed the NHB-18NS preamplifier and the NHB-108 model two amplifier late last year and have never been quite able to shake those experiences out of my head. As this Integrated amplifier, they have a single and mightily focused purpose, and that is to give the musicians we listen to a voice and a way to tell musical tales through one of the most complex art forms ever. It’s what great systems, at whatever price, really should do.

, DarTZeel CTH-8550 Integrated Amplifier

Experiencing both these amplifiers has undoubtedly been a privilege. Still, it has also sparked a quest in me to try to explain why I believe darTZeel amplifiers are so exceptional in a world with many components claiming to do, essentially, the same thing. Let me make something clear – they are not alone in being so ‘musical’ and, to my ears, desirable. But they are one of a small group that shine out and make me want to stop what I may be doing and just sit and listen.

The CTH is unmistakably darTZeel. Its red case and eye-catching gold front panel are instantly familiar, and the quality of the metalwork is beautiful. It’s certainly a bit quirky but in a good and interesting way. Beautifully built close to Lake Geneva, it is designed and fabricated by a music lover to be as close to no-compromise as possible. Let’s say that a device like this is never going to come cheap. In contrast, most bespoke objects, not just audio but also cars, cameras, watches etc., as desirable as they may be, tend to carry a degree of disappointment when you actually get your hands on them darTZeel never disappoints.

Considering its power, the latest CTH amplifier comes in a reasonably compact chassis with gold carrying handles front and rear, giving the component a particular purposeful look. It uses a more conventional volume system than in the NHB-18NS. Yet, with keeping in mind the music must be reproduced with the greatest possible level of emotion, and it is a beautiful thing to operate with its twin soft X-rings, and a slight notion of a haptic response as the knob is rotated. The manufacturer calls it Pleasure Control on darTZeel amplifiers, though most of your interaction with the device will be through a truly excellent remote control. Yes, it too, is beautifully made out of a billet of aluminium in matching gold, providing full access to all features you may ever need. My favourite thing about it is that it will operate even when out of line of sight to the amplifier. For once, I was not forced to get up from another area of my listening room and walk across to stand square in front of a component to adjust the volume!


Every good listening session should be relaxed but concentrated, occasionally bordering on the emotionally intense experience. Getting up and down all the time to adjust the volume or switch inputs shouldn’t be an issue. But, a very friendly nudge and ever-so-polite nod to Hervé – please fit some sort of non-slip feet to the remote. Beautiful though it may be, it’s as slippery as an ice cube and can too easily slide off a chair arm. A small thing but, if I owned a darTZeel, I would have to attach soft dimples to the bottom of the remote handset, which might make it minutely less elegant, but certainly almost perfect.

As far as metalwork goes, the amplifier is superbly executed and the result of 3D-CAD software, a speciality of Mr Delétraz. Laser cutting and welding have taken structural integrity to new levels. The rear panel is a model of efficient design. With seven standard inputs, (RCA and XLR, and, of course, the Zeel 50 Ohm BNCs), superb speaker terminals (4mm banana or spade), as well as RCA and darT outputs plus a couple of USB ports, a fairly compact space has been well exploited. The front panel has the aforementioned Pleasure Control and several small push buttons for input selection or other functions that feel like perfectly polished steel ball bearings. They are relatively inconspicuous as the panel is dominated by the volume control and a plasma screen that shows the volume level and allows each input to be configured through the menus. It’s also legible from tight angles. It is easy to miss small design features like a scalloped channel that houses all the 16 switches and the IR receiver, or the volume control with its central darTZeel logo. For me, it is a thing of beauty. This is, of course, purely a matter of taste and lies in the eye of the beholder. It’s modestly eccentric, but I like it. Internally, the darTZeel is impressive, too. As you may expect with an integrated design of such power, the dual-mono layout is designed around a massive toroidal transformer which deals with the power section.

In contrast, a smaller transformer sits piggy-backed on top of it and caters for the preamplifier section. There is, I am told, a way of isolating both sides of the amplifier to use it as a pre or a power amplifier through the menu, but I never used this option. Another interesting feature is the dedicated USB key that I mistook initially for a keyring. It stores the owner’s name, the serial number of the unit, installed firmware version and voltage settings. This data and would subsequently be used to implement any firmware or software settings.

It should go without saying but probably warrants repeating that equipment of this nature really must be used with suitable components and carefully installed down to the smallest details. My listening was performed with the dCS Vivaldi CD transport and DAC while the streaming included a dCS Bridge and Roon Nucleus. All electronics were placed on a Stillpoints ESS rack, while cables were the ultra-fast and very explicit Nordost Odin 1. The same cable also connected the darTZeel to a pair of the Wilson Audio Duette 2 speakers. I do consider this to be a well-integrated and spiritually rewarding music system.

The amplifier was rather shy out of the box but, after suitable warming up period of 24 hours, music moved onto another level and continued to improve for quite a while after. Long, mood-driven, listening sessions became something to get excited about and as events to look forward to. To say that, in these strange and intensely weird lockdown times, this system helped in some psychologically therapeutic way too, would be an understatement.

With a nominal 200 watts into 8 ohms, the CTH-8550 MkII is a little more powerful than the NHB-108 power amplifier but, as far as my domestic needs are concerned, I would say that power was more than adequate through either one of them. They seem to have deep wells of resources to draw on and the speed with which they deploy the available power, regardless of level, is stunning. The 8550 is one of the very best amplifiers I have heard for low volume, late-night listening.

There’s an interesting thing about pre/power amplification as opposed to integrated amplifiers, especially from the same manufacturer that I need to touch on before I get into the listening. Conventional audiophile reasoning tells us that the pre/power route is the way to go—better instrumental separation, imaging, etc., etc. I agree with all of this except there’s a but at the end of the sentence. For years now, I have found instances where a really good, integrated design had a musical togetherness that was elusive and special. The somewhat tedious audiophile in me readily acknowledges all the goodies that the pre/power route brings to the party, but I have to say there is something so focussed and unified about the CTH-8550’s approach to music that it has completely seduced me. The sense is that it is always on the side of the music as opposed to the audiophile. Don’t misunderstand me though, given the choice I would still take the pre/power darTZeel over the integrated amplifier. It’s just that the CTH-8550, as a great musical storyteller, though different, never really sounds like it is even remotely compromised.

An excellent audio system should be Chameleon-like and almost indistinguishable from the music it conveys. And quite often, when you hear new music with a new component in place, it becomes an experience that has a freshness and intimacy living inside your head, floating in and out of your consciousness as you go about your daily life. Such was the case with Is That So? by John McLaughlin, Shankar Mahadevan and Zakir Hussein. From being something of a McLaughlin fanboy in the past, I thought I was probably done with him after a number of albums plus a live performance that was so full-on and blisteringly intense that they were close to exhausting. His machine-gun guitar lines had become like odd parodies of the early days of the Mahavishnu Orchestra with little resting room, intimacy or space. Whenever he played slowly and with melodic consideration, I loved it. Is That So? is a full-blown Indian spiritual soundscape, dripping with ambience and showcasing Mahadevan’s remarkably agile voice slip, sliding through unusual scales and melodies. At the same time, John provides a synth guitar backdrop, supplemented with some ridiculously good percussion from Zakir. It’s an imposing atmosphere and suits specific day or night moods perfectly. But, be warned, this is powerful stuff, and you might only feel able to dip in and out in small doses.

The darTZeel-fuelled system made this experience like going to a cross between a theatre and an Indian festival. This amplifier brings tremendous precision to the occasion, but with warmth and friendly richness that is calming, yet unusual. This has nothing to do with bandwidth or bass solidity, but more so with meaning and the sheer textures or harmonic interplay between the remarkable vocals and McLaughlin’s decision to play the role of a complex drone instrument. It’s the experience and involvement, rather than the audio artefacts that leave their mark. Close your eyes, the audio system vanishes from in front of you, and that is the best audio experience you can get.

, DarTZeel CTH-8550 Integrated Amplifier

Inertia within an audio system and more specifically, within an amplifier and its ways with music has been a fascination of mine since I first tried to unravel the secret of David Berning’s magnificent QZ amplifiers many years ago. The unforced way which each note unfolds and lives contrasts sharply with a feeling that the amplifier is electronically ‘shaping’ the music. Both darTZeel based systems I have listened to over the past year, have performed very much in the same way. There is very little sense of any grip by or from the amplifier. Notes and musical events just happen, and I would say that the unforced precision the way darTZeel deploys its considerable power into musical dynamism, is one of its most unique virtues. It has an open window approach, and it is an amplifier that projects with such scope, that it shows you just how little of the soundstage in the recordings so many amplifiers manage to recreate.

There’s something about the tonal characteristics of the dry balance of the nylon-strung guitar that has always made it a much better fit with an orchestra, rather than the shimmering harmonic bravado of a steel-strung instrument. It’s the contrast of the orchestra against the loneliness of the tiny acoustic body of the guitar that helps Rodrigo’s Concierto De Aranjuez be such a compelling piece of music. Likewise, the Sonata Suite from Josep Pons featuring Flamenco guitarist extraordinaire Tomatito poses vast challenges for audio systems due to its perspectives. While many systems, though bristling with all the things that audiophiles perhaps traditionally look for, they at the same time bring the tension into the room and it all ends as being instead’ a matter of fact’. There’s power, lush, colourful tonality and romance here as the scales and melodies of north Africa drift across the Mediterranean, before finding themselves caught up in a swirling dish of memorable melodies, handclaps, punctuating foot stomps and percussive fire. The darTZeel is in its element with such a fusion. You simply cannot give this amplifier too many balls to keep in the air. The soundstage (again) is mighty and gives the air and space these musicians demand to bring a piece of complex music to life. My system had a sense of relentlessness about it. Ask it an exceptionally complex musical question, and it always seemed to have the correct answer. A miraculous recovery response matches the speed and power of delivery, and this interaction brings the story to life. Nothing drifts by with the darTZeel as it does with, so much of what we might call, ‘high-end’ systems. It has a clarity of musical purpose that extends beyond the singular momentary performance of the amplifier and into a rare ability to tell the story through pure musical colour and expression.


Forget the debate about tubes v solid state. Amplifiers like the darTZeel transcend such things. Some amplifiers are just really, really good to listen to. It’s as simple as that. It surely has to do something with the ‘voices’ the amplifier can convey to us and musical tales they tell. It is harmonically rich, very clean, crazily textured and able to resolve everything from micro to large scale dynamics plus it is immaculately seated timing-wise, which is crucial. You don’t need constant examination and evaluation. It would be way too crass. The system just lives and breathes atmosphere. That’s what we have here. The CTH-8550 MkII is a wonderful amplifier because it brings you face to face with the art form called music, and you won’t find how it does it on any spec sheet. You just listen, get involved, and give it your trust. If you love music for its form and emotional power, the darTZeel will thrill you. I love it.


  • Type: Dual mono integrated amplifier
  • Power Output: 200 watts RMS (230 watts peak) @ 8 ohms
    330 watts RMS (360 watts peak)
    @ 4 ohms
  • Inputs: 4× RCA, 1× XLR, 2× Zeel BNC, 1× MM, 1× MC (phono inputs are optional)
  • Outputs: 1× RCA, 1× RCA (record),
    1× darT BNC, 1 pair speaker
    (4mm or spade)
  • Frequency Response: 3Hz–300 kHz
  • THD: 1% from 7 Hz to 77 kHz
  • S/N: 115dB (A)
  • Dimensions: 170 × 440 × 335mm (H×W×D).
    Depth with handles – 415mm
  • Weight: 28kg
  • Price: £25,000

Manufacturer: darTZeel audio

URL: dartzeel.com

UK Distributor: Absolute Sounds

URL: absolutesounds.com

Tel: +44(0)208 971 3909



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