DarTZeel

World class Integrated, Stereo & Mono block amps & Preamps from Switzerland
one man’s uncompromising passion for music and its reproduction

darTZeel was born out of one man’s uncompromising passion for music and its reproduction.

The result of two decades of research and experiment, darTZeel products are intended for discerning music-lovers and audiophiles the world over.

Our true passion for music reproduction, which we have nurtured for 30 years, led us on a long quest to design audio machines that can convey the emotions at the heart of a musical performance. 
We are very proud to introduce the long-awaited result through our darTZeel product line.
Most consumer products today—even some very expensive audio components—are designed primarily from the standpoints of manufacturing efficiency and cost savings. 

We beg to differ.

At darTZeel, the only question we want to answer is: Does it make the music feel real? 

Our passion drove us to spend 16 years researching and developing every possible aspect of a new audio circuit, embodied in a completely new amplification approach. 

You can be assured that for us to spend 16 years on one design, “measured performance” alone was not our only goal.

Our products, before anything, are designed and realized from a purely humanistic point of view. For us, music is not only a means for communicating and listening. Far more than this, for us music is a powerful means of soul expression—even of spiritual development.

Emotions that music generates are to be carefully taken in account in the design process. Technology is only then applied to enhance the emotions, even transcend them, without altering them.

Once that goal is reached, we then can concentrate on the "electrical performance" aspect. That’s why we have a test bench.

Listen first, measure later.
Never the other way around.
That is the way we design our products.

--------------------------------------------------------------------------------

Very often, people reason and come to conclusions by analogy. This is because our human nature is greatly guided by intuition. We also tend to extrapolate unknowns from things in our daily life, or we try to draw parallels with already-known things.
This typically human behavior greatly enhances our communication capabilities.

Every music lover, being at least something of an audiophile too, will have already compared one or two audio systems with a real musical instrument, especially when the reproduced sound comes very soon after the real event.
Musical timbres are also compared to colours, tastes, and flavors, exactly like good wines are. In both cases, however, excellence is rarely due to chance…

Do you know how one creates a musical instrument, exactly?
Let us take as an example the double bass, truly a masterpiece of the luthier’s work.
Everything in this instrument reminds one of fine art and elegance.

Clues to technical matters are not obvious, so fascinating is the instrument’s beauty. Yet, the instrument maker is in addition to being a skilled woodworker and perhaps even a musician, a pure technician.
The huge pull the strings apply to the neck requires failsafe engineering know-how.
Materials not only need to resist to that formidable traction, they also have to last, for quite a long time indeed.

Different species of wood are utilized in the construction process. The neck, the fingerboard, and the resonating body, each has its own characteristics, being mechanical resistance, density, and typical timbre.

What will ultimately make the difference between an ordinary instrument and a true masterpiece, is the maker’s technique. We mean that the technique is used to serve the music, and not the other way around. Everybody knows that the instrument maker will always make the right choices in choosing the woods and marrying them together for the best balance between the technical constraints and musical aims.

When a professional musician buys an instrument, he or she will probably choose it first for its sound, then for its build quality.
The quality of the construction, though, is of almost the same importance as the sound itself. A well-made instrument will last virtually forever, and the high price paid at first will be many times rewarded by the pleasure of the happy owner.

--------------------------------------------------------------------------------

In audio electronics, it is usually rather difficult to show that an aesthetic requirement led directly to a particular technical choice. It is hard enough even to demonstrate that one particular technical option has some valid role in obtaining better sound reproduction.

 Complicating matters even more, most audio manufacturers use terms that can be misunderstood, or simply not understood at all, by the non-technician audiophile/music lover. Perhaps even several of those terms are not really helpful, and are only destined to confuse the customer. Thus, such components appear to be more mysterious than they really are, especially when those mysterious "secrets" are well preserved.

The true secret is the one which we can show without false modesty, and without particularly pointing at it, so well is it blended into the whole.

As said above, every musical instrument, while certainly made through some secrets transmitted from generation to generation, at the end, these secrets perfectly and smoothly blend together in what we usually call know-how.

This know-how can always be admired, but never copied by non-initiated people. The instrument maker will be the only one able to reproduce identical instruments.

Our products are manufactured in such a way that we can show absolutely every detail, from the machined aluminum case, to the last touch of finish even applied to inner parts, as well as the electric schematics of every module. There is nothing to hide at darTZeel.

The true secret, if any, lies in the result which is brought about by the interaction of the whole. Taken separately, even though giving its utmost performance, no single module can reach its full potential.

Featured

All Products

Reviews

Videos

Featured

DL AM NHB458
NZ$ 222,500.00 (incl. GST)
All audio circuits already shares the philosophy that inspired the popular NHB-108: no connection, no switch, relay or similar component, the signal path (except a relay of high quality, inert gas,...
A recent (unpublished) letter to the editor argued that the reference for audio perfection is the...

All Products

Integrated amplifiers

DL 01 IA LHC208
NZ$ 19,995.00 ea (incl. GST)
The LHC-208 "danalogue" streaming DAC with 200w Integrated amplifier first introduced and highly acclaimed at CES in Las Vegas last January, you will discover the new way of playing very high...
EXTENDED REVIEW: You’ve got to hand it to darTZeel: the boutique Swiss brand barely registered in...
Integrated amplifiers
DL 03 IA CTH8550
NZ$ 30,995.00 ea (incl. GST)
Our passion drove us to spend 16 years researching and developing every possible aspect of a new audio circuit, embodied in a completely new amplification approach. You can be assured that for us to...
No compromise « all in one » music machine darTZeel is proud to introduce the new CTH-8550 full...
R E V I E W One thing I didn’t experience a whole lot during my recent trip to Switzerland was an...
Integrated amplifiers
DL 04 IA CTH8550
NZ$ 31,995.00 ea (incl. GST)
Our passion drove us to spend 16 years researching and developing every possible aspect of a new audio circuit, embodied in a completely new amplification approach. You can be assured that for us to...
No compromise « all in one » music machine darTZeel is proud to introduce the new CTH-8550 full...
R E V I E W One thing I didn’t experience a whole lot during my recent trip to Switzerland was an...
Integrated amplifiers
DL 05 IA CTH8550
NZ$ 32,995.00 ea (incl. GST)
Our passion drove us to spend 16 years researching and developing every possible aspect of a new audio circuit, embodied in a completely new amplification approach. You can be assured that for us to...
No compromise « all in one » music machine darTZeel is proud to introduce the new CTH-8550 full...
R E V I E W One thing I didn’t experience a whole lot during my recent trip to Switzerland was an...
Integrated amplifiers

Preamplifiers & Line-stages

DL 08 PA NHB18
NZ$ 49,995.00 ea (incl. GST)
Leading-edge audio electronics  At this level of performance, every detail is of prime importance.   The delicate, small signal delivered by the sources is amplified by discrete devices, or...
Extended review:
DL 09 PA NHB18 P
NZ$ 59,995.01 ea (incl. GST)
Leading-edge audio electronics At this level of performance, every detail is of prime importance.   The delicate, small signal delivered by the sources is amplified by discrete devices, or by...
Extended review:

Power amplifiers (Stereo & Mono)

DL 12 AP NHB108
NZ$ 44,995.00 ea (incl. GST)
Some review: If you discovered the darTZeel NHB-108 model one for the first time through our web site, it may be helpful to recall some design basics:     * No global Negative Feedback...
DL AM NHB458
NZ$ 222,500.00 pr (incl. GST)
All audio circuits already shares the philosophy that inspired the popular NHB-108: no connection, no switch, relay or similar component, the signal path (except a relay of high quality, inert gas,...
A recent (unpublished) letter to the editor argued that the reference for audio perfection is the...

Reviews

Interview with Herve Deletraz - DarTZeel
Matej Isak - Mono & Stereo

When and how did all started for DarTZeel? 

The full answer is in the next question. It is almost the story of my all life. The name darTZeel is the anagram of my family name "Delétraz". I introduced my first commercial product in 2002 at the Stereophile show in New-York, and in 2003 I started to sell machines in USA, my first country where darTZeel products were distributed. The rest came as time went ahead

Can you kindly tell us about your background?

Well, that's quite a long story indeed.

At 10 I received my first Philips Electronic kits (the series 1000 for those who maybe remember) and I built my first AM 2-band super heterodyne radio. At 12, I was already found of music reproduction, and I was lurking about all audio gear I couldn't afford, through specialized magazines or various audio shows.

At 15 I started my degree in electrical Engineer School of Geneva (E.I.G.), and I ended in 1984, realizing my very first audio amplifier, actually a Class-D amplifier, which sounded pretty good!

Anyway I wasn't totally satisfied, so I went back to full analog, and I started the NHB-108 project. It took me 16 years to finalize the NHB-108. I got several patents since the circuit I designed was never achieved before, and at the time it was one of the "simplest" designs regarding the signal path, which still offered very wide bandwidth without using any global negative feedback. Of course it was not 16 years of full time designing. Yes, we are quite slow in Switzerland, but here the reason I also had to work in order to earn some money… :)

Anyway taking so much time helped me keeping away from choosing designs which already existed. I had all my time, nobody was pushing me. It was really holy moments, since pressure is a thing I have to cope with in the present time. I like pressure and challenges, but sometimes I think about how sweet the beginning was!

Did you have any strong influences or people you looked up to (or still) do?


Oh, yes, for sure! Here in Switzerland were quite some nice brands like Nagra, Thorens, Swiss Physics, and especially REVOX – STUDER. I was especially found of Willi Studer, the founder of REVOX, and at the time the biggest audio show was the FERA in Zurich, organized by Willi himself. I owned almost every gear REVOX produced, save for reel-to-reel machines which were too much expensive for me. Only 20 years later I started to collect those wonderful tape machines… :)

Does DarTZeel name have a special meaning (TZ letters) or it just look nice with capital letters?

Yes! As you can see in previous answer, the name REVOX has the middle letter in big capital. I chose to use same thing in a kind of y tribute for the guy I admired in my teenager years. I also took the opportunity to dress the "Z" like a Zener diode, a basic electronic component.

In your venture you explore digital domain seriously long before anyone else, but didn't stay there. Why?

At the time I designed my first digital amplifier, I had to build all the electronics for the analog to digital domain, since such kind of converters didn't exist off the shelf, especially with the level of performances I needed. For a long time – several years - I tried to develop the "perfect" digital amp, but the biggest problem was the residual noise due to the clock jitter, which I wouldn't want to correct using a global feedback – my original 1984 digital amp was already an open loop design – and the biggest problem was the frequency response, dramatically affected by the speaker impedance, due of the use of the output filter.

Anyway I am still thinking about a digital amp, just in order to know what I would be able to do in this new, promising century…

Is digital audio coming close in these past few years?


If you are meaning "when will darTZeel release a digital source", frankly I do not know the answer myself… Very recently I heard a couple of truly fantastic digital players, yet at very high price/quality ratio. Designing and – trying to – beating these already excellent competitive products would be quite difficult, if the price enters into consideration. Furthermore, digital players can still greatly improve in the next 5 to 10 years to come. Maybe when we will be closer to the asymptotic curve of possible improvement, I will think about a digital player.

On the other end, even if I am sometimes tempted into this kind of venture, I would like to concentrate on pure analog products for a while still, since there are plenty of things I have in my silly mind…:)

If a digital product comes, it will be only – almost – by chance!

You're not the biggest fan of balanced topology. Double the electronics, double trouble?


Well, yes, and no… It mostly depends on which topology you will use for which kind of application.

I won't enter into deep, technical and physical explanations here, but in the very nature of sound propagation into the air, the waves are asymmetrical, not balanced. Balanced topology was primarily used in pro studios because they needed running very long cables without picking up noise, and they also took this opportunity for providing the known +48 volts phantom supply for microphones, a thing you can't do in single ended connections. However, if you look inside a mixing console, you will see that the signal is translated into single-ended mode, balanced mode only be used for carrying the signal outside (in and out) the console. If you look at loudspeakers, too, you will see that internal crossovers are - 99.9% of the time – single ended, not balanced.

In my own designs, yes I naturally chose single ended mode, since I wanted to have as low as possible components in the signal path. Balancing would have effectively doubled the part count.

Sometimes it's hard to explain analogy of musical instruments, but you're using the same analogy and I do often. There are always choices to make and places to explore when it comes to an instrument. Real artisans know about behavior o materials and how to implement them into specific sounding instrument. Would you agree with this? Please elaborate...

It is not always simple to make simple comparisons between music instruments and electronic gear, especially when one states that electronic components do not have moving parts. Too much often we can be misled by the fact an electric signal is two-dimensional only. This is almost true at first glance, but in reality everything in this human world – we won't talk about quanta here :) - is three-dimensional, even four if you add time. This is this fourth – time – factor which is key parameter in music reproduction.

An acoustical instrument generates its music in a very complex field, which is supposed to be omnidirectional, but actually it is even more complex than this, since the sound waves are not equal in all directions. When you try to reproduce the music by electronic means, you have to accurately reproduce the timing of the recording, without altering the relationship between two consecutive signals.

The human ear-brain system is much more sophisticated than the best available microphone. Electrically speaking, frequency is directly related to speed. In our human world, we can discriminate frequency and speed. We have different "sensing captors" for different sensations.

A very old man, for example – just like me :) – cannot hear anymore frequencies above 10 kHz, but he will easily recognize the difference between a triangle, a cymbal or a bell, while a microphone cut at 10 kHz will dramatically round the edges to the point the transients will look almost the same…

So, when it comes to audio amplification, if we can carefully handle transients and time relationships between tow very close, consecutive music "bits", the ear-brain system will "accept" it as being natural and life like, without needing any specific listening "effort".

This is what I tried to realize, and I think that it is one of the reasons why people do not hate our machines…

One of the things that I'm trying to push with my reviews is musicality. I don't care about price tag; if specific audio component cannot convey music with it's natural emotions, then it simply fail. There might be lots of approaches to this, but few succeeded. Would you describe your way...

The biggest problem, especially when you are in a "never-ending-design-process", is stopping at a point in order to actually produce the machine you created. I am sure most designers feel the very same, trying to improve further in the last minute, just before the marketing guy shouts "Stop now!"

As darTZeel is still quite a small to medium size company, I have a bit more latitude in this department, and generally I can stop "just before it is too late", yet being quite comfortable with the result I was looking for. At the end the price is inevitably a key factor, and I perfectly realize that our machines are not the most affordable ones. I can swear you anyway that I do not design machine to be expensive just for the sake of luxury, but for musical pleasure first.

When a product does not fulfill my goals, I do not leave it go into production. When the first final prototype eventually works, then I call all my favorite friends and I glue them to the listening chair for hours until they tell my if they like it or not…

Back in 1999, I was lucky enough to find a quite simple design which worked beyond all my own expectations, and most of darTZeel products are directly derived from this original design, which seems to have proved for itself. Fortunately, I do not keep on what was an already good design, I always try to go ahead, and as long as I solve a 2 + 2 operation, I will think this way… :)

There's a saying, that music can be a window of the soul. Would you agree?


Oh, yes, I do even more than just agreeing. When people ask me how I do making my components sound this way, it is always very difficult to give an answer. Simply because I actually do not know! And as I do not know, I generally say that I put a tiny bit of my own soul in every machine. This is not immodesty, but only the closest way I could describe my life time devotion into music reproduction.

So definitely yes, music is a big, full, sensitive and magical window opened to the soul.

What do you think about resonant imprint of elements, enclosure, etc? How much those affect the sound?

For sure the enclosure is a key factor in audio components. Almost all electronic parts are highly "micro phonic" and transmit vibrations into the circuit. When we perform the initial test measurement of our phono stages in the bench test, they are not already installed in the preamp housing. If you clap your hands, even at more than 5 meters, you can see the sound wave on the FFT analysis gear! So the reason we keep very quiet at this moment… External unwanted magnetic fields also are of quite big influence on the circuits, since any piece of metal is subject to react with such kind of noise disturbance.

Of course, a phono stage is more sensitive than a line stage, and the latter more sensitive than a power stage, but anyway at every step you have to be careful. On the other end, a power stage uses a bigger transformer which generates more field than a line stage power transformer, and so on.

Internal layout is also very important, for the very same reasons described above.

What are benefits of open-loop input and output stages?


The big advantage of an open-loop circuit is that its frequency response does not depend of any "retro-active" compensation. It does mean that the phase and the internal gain of the circuit will virtually not vary versus frequency. In a closed-loop circuit, of course you can compensate a lot of things like distortion, input/output impedances, but all these corrections are not applied the same way versus the frequency to be reproduced. A bit like a Father with his Son. If the son always asks his father what to do, it is a good thing for most of the time, but the son will not feel free to do his own way. If the father does not tell his son all the time what doing, the son will better exhibit his own character and personality.

An open loop stage will not try to "correct" an error, but will just amplify the signal it receives. Of course if the circuit is poorly designed the result will be poor. But is the circuit is quite okay, the signal will be just amplified without being "corrected" all the time. Furthermore, a closed-loop (negative feedback), will never act in real time, but always with a time delay, no matter if this delay is very short, supposedly beyond human perception. I do personally not believe that anything in the music reproduction is "beyond of perception". The biggest difficulty is designing an open-loop circuit with wide bandwidth, since these are two contradictory things, but it is possible anyway… :)

Lately everyone is talking about power supplies. How important is a power supply in your view? What differ in your designs from other audio manufacturers?

I do not think I am very different than others in designing my power supplies. I wouldn't simply say that "a power supply is a power supply", but here again, I think that when you know just enough about Ohm's law, you have an idea which kind of power supply to use for which kind of circuit. Just let us say that in power supplies I also favor simpler design, with open-loop regulation when possible, and as less as possible components in every power supply stage – which doesn't mean I do not use multiple regulation steps when required.

Oldest debate. Tubes vs solid state. You probably went through the both schools and obviously concluded something. What and why?

I wouldn't be so categorical about which is the best. Tubes are very fast devices, and are still used in broadcast emitters for the carrier frequency. They also are capable of very big power – still in broadcast application – and they can behave as well as transistors do. I personally believe that I could design a tube amplifier with a sound very close to my machines, or vice-versa. It is true that when I went to school, we concentrated on the transistor, and I am more comfortable with them. Transistors have the advantage of being smaller, more reliable, less expensive, and much cooler. But tubes are not dead to my point of view, especially in music reproduction. I actually think that solid-state amplifiers generally sound much less good because it is "so simple" to use a lot of them and applying all various artifacts in order to compensate their supposed flaws, rather trying to think about what we can do with a handful of transistor part count, exactly what our grand fathers tried when they only had a couple of tubes to play with…

There are lots of speculation with NFB (negative feedback). No global negative feedback with DarTZeel?

Negative feedback is a closed loop. Degenerative feedback is a kind of compensation made by a resistor directly connected to the end of the transistor, and it is not like a real negative feedback (the "loop" is only created around the resistor in this case).

There is no any design which can work without any kind of negative feedback.

In the darTZeel circuits, we only apply a very small degenerative feedback at the input stage. The second stage set the voltage gain, and this stage uses a small negative feedback. Actually we use two half-negative feedbacks; one for each polarity leg, in order not the positive part will directly influence the negative part, and vice-versa. The third, output stage is fully open-loop, and do use any kind of negative feedback. And of course we do not use any global feedback. A global negative feedback consists in taking a part of the output signal and feeding the first input stage in reverse phase in order to compensate any flaws; this is the worst type – but the easiest one – of feedback one could use in audio reproduction.

Life span of products comes with knowledge and applied technology. Your philosophy address this profoundly...

No big mystery here, just some experience over time… When you know that the lifespan of a component is halved each time the temperature rises by 5° Celsius, you naturally try to take care about internal thermal dissipation… :)

Specific warm yellow/gold aluminum front plate finish with red enclosure radiate with unique, distinguished, dandy kind of timeless appearance. What drove you to this harmony?

Thank you for calling this "harmony". It was just about what I thought, but not everybody liked these colors right at the beginning. I actually wanted to make my machines differently not only in their sounding, but also in their looking. I chose these colors because I liked them, and also because I found that they would nicely match old wooden furniture. Funny enough, this is only several years after that I realized that red and gold (or yellow) is the official colors of the Geneva flag… Maybe I was influenced unconsciously…

Now, after quite some years, our colors are now a trademark, and almost anybody can recognize our brand just looking them at a glance. Actually all our "old" customers like them and say they love listening to music in red and gold… :)

There are many ways to incorporated volume. You choose opto-modul for gain control and I'm guessing starlights wasn't the only attribute for that. Kindly elaborate?

When I designed the NHB-108 model one power amplifier, I decided not only to use a very "simple" audio circuit, but my goal was also to preserve the signal path the best I could. So the reason the NHB-108 has no any contact or relay or switch in the signal path; when you plug the AC cord off, the machine still plays for about 20-30 seconds, just draining out the capacitor bank.

The big challenge was to design a preamplifier with the very same design philosophy. My big problem was how could I select a source without physically switching it, and even more important, how could I vary the loudness level without involving a potentiometer wipe or relay, or even analog switched arrays (which involves MosFets).

After thinking quite a lot about this, a… light went on in my head. Why not using the light for activating light dependent resistors? Well, the idea was not completely new, since I know other designers already thought about the idea. However, this technology has a big drawback: these components are not linear at all, and they do not act the same from sample to sample… Then the God of software entered. We were able to calibrate and control these special analog optocouplers the way we wanted.

The result is the NHB-18NS, the first and only preamplifier in the world which is a truly "zero contact" signal path design from input to output. Avoiding any contact greatly improves transparency, and as far as I know, customers like it very much…

Your obvious choice are bipolar transistors and you're not even generous with used amount, but output power could make many amplifiers envious. Why?

Here again, I chose bipolar transistors because they are easier to drive with very low part count. I also love their sound which is – to me – tighter and more full bodied than MOSFETS. The latter are very good for class-D amps, however, but this is another story….

What was with the "Noose" happy face design of NHB-108?


Well, as you certainly know, I do not take myself too much serious. Music must be fun, after all. As the 2 big LEDs reminded me Eyes – I called them this – I naturally called the central switch "Power Nose". The same way I called the loudness "Pleasure Control" in the preamp.

Only two bipoloar transistor per channel?


Yes. I wanted to use very few components. If not made extremely carefully, multiple parallel pairs could lead to unfocused sound, because of different propagation delay time. With only one pair, this problem simply does not exist! (The just released NHB-458 use 4 pairs instead of one, but the circuit topology is different here, benefiting from nine more years of research…)

Usually you cannot obtain more than 50wpc with a single pair. Thanks to my specially designed Monitor Control circuit, I was able to monitor all parameters of the transistors, and could make them work very close to their maximum ratings, still being always in the safe operating area. So we could obtain a high as 230 watts per channel into 4 ohms (claimed 160wpc), as measured in Stereophile magazine. People who do not own an NHB-108 might think it is a low power amplifier, but it is not at all. It sounds quite powerful, more than its power rating might suggest.

DarTZeel CTH-8550 made big impact in media and on high-end audio shows. Would you say that is a DarTZeel signature sound or a lack of?

The CTH-8550 marked a truly new corner in darTZeel products. Not exactly as good as the separates, but very, very close, at a much lower cost. CTH stands for Close To Heaven, and "8550" was for 85% of the quality sound of the separate, at 50% of the price. The sonic signature is the true darTZeel one. You have to listen to it to believe your ears. It is only when you directly compare it to separates that you will notice the difference.

Is NHB 458 just a pure statement or true cost no object design, cut no corners, speak no word approach?

None of the above. Actually there were my distributor who asked to offer a big, big amplifier. I replied "Yes". But only if I could make it sound even better than the NHB-108, which is the case at the end. I would never design it if the sound wouldn't be at the level of performance I wanted.

It is very close to a real no-cost-object machine. Right now, it is my no-cost object machine, actually… :)

In recent years there is a lot talk about price barrier of 10.000$. CTH-8550 is round double that price. DarTZeel components are object of choice for those who recognize and respect fine craftsmanship. But, where is the line or price border that you think is necessary?

It is true that all darTZeel components are quite expensive. But it is doubly true by now.

The past 3-year of economical crisis pushed the Swiss franc to very high value, and we truly suffer from this. Only eight years ago, 1 US dollar was 1.7 Swiss francs. Today, the dollar is almost on par with the Swiss franc. Almost all European currencies are quite weak too, and I can only deplore this fact.

Anyway, when you open one of our machines and look inside, you understand quite quickly why the value is high. Our quality of building is often compared to Swiss watches, and I do not talk about Swatch here… :)

Where does hi-fi stops and high-end comes in for you?


20 years ago, we only spoke about Hi-Fi. The term high end came later – at least here in Europe – and was just another way for qualifying better audio systems, compared to those "compact systems" you could buy in the 70's and 80's. To me, there are only audio systems which make real music, and others. This is not a matter of price. While our products are among the very up of the hill, for sure you can find already very satisfying, musical systems, for much less. It is just like a car. If you want the fastest one, you will have to pay the price. If you just want to go from point A to point B, any other good car will do the trip…

What would you say is the goal of DarTZeel audio?


The primary goal is sharing a true passion for music reproduction. darTZeel is still a young company at the moment of writing, but for sure it will grow along the coming years. We will try to expand our product line step by step. One of my dreams would be able to offer outstanding quality at more reasonable prices. But the road is not so easy, and it will take some time still. Be sure that I work on this very hard.

There is vivid difference between DarTZeel and competition. What is that exactly?


I do not really know if there is a "vivid difference" between us and the competition. I think what is different is the luck being independent and not having a dozen of engineers giving a dozen of different thinking points of views. For sure I do not design anymore all products 100% myself. I still continue – and I will continue as long as I will be able to – to imagine products I dream of, then I also work with very sensitive partners who truly understand what I need and what I want. This kind of synergy allows me to keep the drive wheel the way I want, and at the same time I can listen to good advices I'm told…

What audio/music references do you use when designing the prototypes?


Very good question! Well, a lot of old records (Jazz/Pop/Rock), most of the time not well recorded. What I am looking for is the emotional feeling which is present in the music, rather than the quality of the recording itself. A lot of designers simply forgot this kind of approach, and I think it is too bad…

Is there a way to offer more affordable DarTZeel integrated amplifier, or do you plan this in future?

Yes. Please refer to my other answer above (goal of darTZeel Audio).

Many liked your phono stage in CTH-8550. Can you tell us more about it?


As I wrote above about tube versus transistors, I believe you can also design a very good phono preamp even if you do not use discrete transistors only… :)

The phono stage in the CTH-8550 is using dedicated integrated circuits, but not dedicated for phono stages… We took the microphone amplifier stage approach, and it paid off, apparently…

What are your views on whole analog/vinyl revival or is it at all?


Which revival? Vinyl didn't die, and it won't ever die. So many LP's are available in the world. Even if scratched, this media is the only one I know which can survive more than 60 years without losing a single bit of quality. Not sure it is the same about hard disks…

Should we fire up analog vs digital?


Of course not. Both will cohabit together. Each of them has its advantage and its drawbacks. I think in the future they could eventually merge (how about analog music on hard disks?).

What is your connection with Playback design? They're offering direct connection to your amplifier.

Andreas Koch, the Playback Design designer, is friend of mine. He his Swiss, too, but he lives in California. When he designed is MPS-5, he kindly asked me if he could implement a dart 50-ohm output.

I simply answered: "Yes, with great pleasure!"

How do see current state of high-end audio?


We are in some trouble years. Digital was the best ever to come, then MP3 arrived. This added a lot of confusion, misleading "digital" and "quality of sound". This our task – we, old audio guys – teaching coming generation about how great music can be when properly listened to it. I am quite confident with the future, and I am pretty sure that my grand' sons will buy vinyl's!

What holds future for DarTZeel?


Depending on how is the "future" for you? I am 48 years old in next October, and I am in quite good shape. I plan to stay in the business for these next 50 years… :)

So you will certainly see plenty of other products in the future. I mean new products. We do not like to revamp existing products with a new housing and call them "next generation". Our products are made to last "forever". They never come obsolete if and when a new "brother" arrives…

Any last thoughts for our readers?


First of all, thank you for reading everything until the end! It was a very long time I didn't almost tell my all life in an interview… :)

I would like to tell all your readers that music is more than just audio components. Music is a universal language, which conveys all possible emotion palettes. If and when you will build your audio system, please do not forget one thing: if you can feel some of the emotion through your system, just keep it as long as you will like it, no matter it is vintage or very new.

Instead of spending only in components, buy software: CDs, SACDs, Vinyl. The more you will have music, the more you will be able to know if your system needs an upgrade. Audiophile demo disks will not always tell you the truth…

With my very, very best regards - Hervé


Matej Isak
Mono & Stereo

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.
the darTZeel NHB-458 is easily the finest power amplifier I have ever heard in my listening room,
Michael Fremer

The first listen in my system made one thing clear: The NHB-458s delivered "never heard before" high-frequency cleanness and transparency combined with as perfect a high-frequency transient response as I've heard from any amplifier, all emerging from velvety-black backdrops.

The NHB-458's transparency and "just right" attack begins at the very bottom of the audio band and extends to the very top. If the Soulution 710 was so fast and clean that I wished it might slow down a bit and reveal more texture, and the MBL 9011 was top-to-bottom coherent but I kept wishing it would tighten and speed up a bit, the NHB-458 was, to my ears, like Goldilocks' favoured porridge: just right. The NHB-458s produced exceptionally clean and transparent high frequencies that combined the speed and fine image size of the best solid-state gear with the textural and transient delicacy and generous harmonic instrumental structures of the best tubed components.

A recent (unpublished) letter to the editor argued that the reference for audio perfection is the sound of real instruments in a real space. The writer claimed that, since the art and/or science of audio is advancing, and because it is a "scientific truth" that the closer you get to perfection, the less divergence there is components, that therefore there should be less difference in sound among the components listed in Class A of Stereophile's "Recommended Components" than among those in Class B, much less Class C. This should be true of loudspeakers, he said, but even more true of top-rated amplifiers, since "they inherently have less divergence."
 
Over the last few years I've reviewed a number of truly fine amplifiers, including the Musical Fidelity kW and Titan, the VTL MB-450 Series III Signature, the Soulution 710, the MBL Reference 9011, and now the darTZeel NHB-458. I can assure you that, while each is a Class A performer, all sound very different from one another. We are a long way from approaching the sonic uniformity predicted by the letter writer, and that's something to celebrate.
 
We all bring to our listening different sets of sonic prejudices, preferences, and past experiences. We listen for or are more sensitive to difference aspects of sound reproduction. That's true for both listeners and designers, and in the case of the darTZeel NHB-458 monoblock power amp, the designer is Swiss electrical engineer Hervé Delétraz.
 
Visually Sensational
The widely divergent reactions among my friends to the distinctive-looking NHB-458s demonstrated that we all have differing visual as well as aural prejudices and preferences. Some loved how the darTZeels looked. Others, not so much.
 
Like darTZeel's NHB-18NS preamplifier, with its brushed, dark-gold front panel and retro-industrial, red-anodized chassis (which I described in my June 2007 review as reminiscent of Radio City Music Hall before its renovation), the NHB-458s exude darTZeelness.
 
This Swiss-built monoblock measures 18" high by 11" wide by 20" deep and weighs 154 lbs. It looks like an art-deco computer tower on a fanciful sled or slippers. Its curvaceous lines, jewel-like finish, and lack of handles made moving and placing the amplifiers tricky.
 
Tinted glass side panels emblazoned with the darTZeel logo let you peer inside, where an enormous cylindrical transformer the size of a hat box, black and mounted on its side, seems to float in space. The core cap, finished in darTZeel gold, completes the scene. As well as being physically attractive, these glass panels serve an electrical purpose by allowing the magnetic fields to "escape" the chassis.
 
The amplifier's entire massive power-supply section floats on a suspended sub-chassis that's shipped locked in place by four large bolts. After removing these bolts, you plug the holes with four gold-plated dummy bolt heads. The suspended platform uses dampers tuned to absorb frequencies from 40 to 70Hz, to block the transformer's 60Hz vibrations from being transmitted to the chassis, and to isolate the transformer itself from airborne musical vibrations.
 
There are actually two transformers: the big one is for power, the small one for the logic and circuit controls. They're mounted at 90° to one another, to eliminate any electromagnetic transmission between them. The power transformer is also separately suspended.
 
The front panel is another work of sculpted art better seen than described. Operating parameters are set via five small pushbuttons below a rectangular fluorescent screen. When not in Menu mode, the screen monitors the amp's peak and RMS outputs. The Power/Standby and Menu buttons flank a status light that goes from red to amber on power-up.
 
A large heatsink dominates the rear panel, with a cutout for connections that include RCA and XLR inputs, as well as a Zeel BNC 50 ohm input, for use with darTZeel's NHB-18NS preamplifier and Playback Designs' SACD/CD player and DAC. While the XLR input is "truly and actively balanced," per darTZeel, it uses a "translator balanced to unbalanced circuit"; darTZeel recommends using the single-ended input with non-darTZeel components, if possible. If not, the performance loss due to the extra circuitry is claimed to be "slightly reduced . . . but extremely small." The speaker terminal is Cardas's single-knob design. Also on the rear panel are a circuit breaker and in/out triggers for remote power-up by darTZeel's preamp.
 
Power at a Price
Five years ago, in my review of the darTZeel NHB-18NS preamplifier, I wrote: "With the introduction of the NHB-108 stereo amplifier, Swiss-based darTZeel quickly established a reputation for pristine, hand-built quality, fanciful industrial design, and elegant circuitry—all accompanied by a healthy jolt of sticker shock."
 
All of that is still true today. Despite being a relatively small company, darTZeel makes products that include the latest in surface-mount circuit-board technology and other modern construction techniques. DarTZeel's products may look fanciful, but their insides are all business.
 
The NHB-458 is immensely powerful, outputting 450W RMS into 8 ohms, 800W into 4 ohms, and 1000W into 2 ohms (and 850, 1700, and 1800W peak, respectively). And with claimed frequency responses of 0.7Hz–700kHz, +0/–3dB, and 20Hz–20kHz, +0/–0.2Hz, it combines ultrawide bandwidth with essentially flat (claimed) response throughout the audioband.
 
Total harmonic distortion is specified at less than 1% from 7Hz to 77kHz. That's fairly high in today's solid-state world (though across that bandwidth it's pretty impressive), but Hervé Delétraz claims that THD "has nothing to do with musical performance." Like the darTZeel's original NHB-108 integrated amplifier, the NHB-458 has a zero-feedback, true open-loop output stage, so there's no output-impedance compensation (ie, Zobel Network). The specified output impedance is less than 0.28 ohm, 20Hz–20kHz.
 
Delétraz cautions that the NHB-458 is not suited for speakers with a nominal impedance of 1 ohm because of its low parts count: despite the high power, there are only four transistor pairs in the output stage.
 
All this power and bandwidth, the 750 joules of energy available from the large-capacitor reservoir visible through the side panels, the open-loop, zero-feedback output stage, the sophisticated operating system, the stunning craftsmanship, the custom extrusion work and anodizing, all come at a stiff price: NZ$215,000/pair. 
 
Operating System
The NHB-458 comes "factory activated"; on turn-on, the screen states that it was built specifically for the buyer. If it hasn't been factory-activated, the amp will operate for 15 minutes, then shut down until you program the two supplied USB keys with codes provided by your dealer. The keys plug into a rear-panel USB port that will also be used for software upgrades, should those become available. I'm not sure I understand the need for any of this. It's not as if a stolen NHB-458 can be shut down by remote control.
 
Via the menu you can select the input (RCA, XLR, Zeel), 26 or 32dB gain (the latter is the factory default), how the NHB-458 is to be turned on (manually, triggered, or when it detects a signal), and the screen brightness. Dealer setup should obviate any need to mess with the menu, and once it's set it shouldn't need to be touched, but it's a good idea to familiarise yourself with its operation. Otherwise, the NHB-458 operates like any other amplifier that lacks on/off switch. Plugged in, it's in idle mode, in which two of them use 4W—not that anyone spending this much on a pair of amps is worried about the electric bill. An important caution: Remove the plug from the wall before making any rear-panel connections—the amplifier lacks any fuses or protection circuits. Hervé Delétraz feels that these detract from ultimate sound quality.
 
NHB = Never Heard Before. Really.
Imagine my feelings of anticipation as I hooked up these impressive-looking monoliths. I had some idea of what to expect—I'd heard the NHB-458s driving Wilson Audio MAXX 3 speakers once before, at a Syd Barrett event in a London art gallery (see the July 2011 "Analog Corner"). Even under those very difficult conditions, the sound was extraordinary.
 
So I wondered: Compared to the competition, how would the NHB-458s sound through the MAXX 3s in my home system? On the Soulution side of fast, tight, and detailed? Or would the darTZeels be "neatly threading the needle between the Soulution [710]'s cool speediness, the VTL [MB-450 Series III Signature]'s assertive top end, and the [Musical Fidelity Titan]'s warmer if less resolving sound," as I reported the big MBL Reference 9011 first sounding? More listening with the 9011 revealed bass response that, while "complete in terms of extension, texture, and finesse," was "less than fully developed in punch and forward thrust," while the top end was "less [than] crystalline on top," with "high-frequency transients [that] were slightly soft compared to the Soulution." Of course, all that added up to pleasingly seamless top-to-bottom performance.
 
The first listen in my system made one thing clear: The NHB-458s delivered "never heard before" high-frequency cleanness and transparency combined with as perfect a high-frequency transient response as I've heard from any amplifier, all emerging from velvety-black backdrops. The attack was neither slightly soft nor a bit too fast or tight, the latter of which can produce a hard, wiry sound that never lets you forget that you're listening to electronics, not live music.
 
Months later, that's still what I'm hearing as I listen to Mel Tormé and Friends: Recorded Live at Marty's, New York City (2 LPs, Finesse W2X37484), which I first heard at a long-ago Consumer Electronics Show through a pair of Apogee speakers in the room of their late co-designer, Jason Bloom. Tormé's friends here include Gerry Mulligan and Janis Ian; the master tape has gone missing, so I pick up every clean copy I see, including the latest, a 1A pressing purchased on last April's Record Store Day for $9. This sonically superb set was recorded by Dale Ashby and Big John Laberdie; played back at the right volume, it's transporting. Even the audience applause seems carefully miked, but it's Tormé's voice that's especially well recorded, appearing between the speakers as if you're listening from in front of Tormé in Marty's on that night.
 
In his liner note, Rex Reed writes: "Being there, with the patina of an artist's bravado rubbing off on the ringsiders, is one thing. But 'in person' albums sometimes make the listener uncomfortable, like walking in the snow and knowing there's a warm, festive party going on down the block in which you're not invited. That doesn't happen here." I'll say!
 
The NHB-458's transparency and "just right" attack begins at the very bottom of the audio band and extends to the very top. If the Soulution 710 was so fast and clean that I wished it might slow down a bit and reveal more texture, and the MBL 9011 was top-to-bottom coherent but I kept wishing it would tighten and speed up a bit, the NHB-458 was, to my ears, like Goldilocks' favoured porridge: just right. The NHB-458s produced exceptionally clean and transparent high frequencies that combined the speed and fine image size of the best solid-state gear with the textural and transient delicacy and generous harmonic instrumental structures of the best tubed components.
 
The very first thing that startled was the way the darTZeels reproduced drums. I just keep playing Larry Young's Unity (two 45rpm LPs, Blue Note/Music Matters MMBST-84221)—and with the organist backed by tenor sax man Joe Henderson, trumpeter Woody Shaw, and drummer Elvin Jones, no wonder! It's among engineer Rudy Van Gelder's best drum recordings, and was one of the first records I played through the NHB-458s. Record after record, my response was "Best drum sound I've ever heard."
 
But less important than such superlatives was why it was the best, and after months of listening to what's still the best drum sound I've ever heard, from cymbals to kick drum and, especially, what's in between, I finally figured it out: the NHB-458's combination of high, instantaneous power, absolutely spot-on attack speed, ideal sustain, and graceful, extended decay. The darTZeel wasn't the only amp I've heard that made drums "pop," but it followed that up with stunning textural authority in the sustain, then equally fast and symmetrical decay.
 
Recently, a Blue Note record producer brought over some test pressings of Norah Jones's catalog, now being reissued on vinyl by Acoustic Sounds. I think what he heard those LPs sound like took him by surprise—in a good way. Turned out he's also a fan of Larry Young, so I played the first track of Unity. His reaction to first hearing that very familiar track through the NHB-458s was the same as mine had been: astonishment.
 
Over time, it became apparent that the same qualities that produced the ideal drum sound brought a clarity and believability to piano recordings. The more crowded the soundstage, the more distant the miking, and the more reverberant the backdrop, the more the NHB-458s were able to lay out that first transient without overwhelming the textural sustain and decay. It's what you hear in a great concert hall—even Avery Fisher.
 
Consider, for instance, a reissue of Brahms's Piano Concerto 1 with pianist Clifford Curzon, and George Szell conducting the London Symphony (LP, Decca SXL 6023/London CS 6329/ORG 103), recorded by Kenneth Wilkinson at Kingsway Hall in spring 1962. The recording was simply miked, which produces eerily lifelike imaging and palpable physical presences of instruments, enveloped by the hall's acoustic. Like most Wilkinson recordings, it sounds great through just about any system. The absence of spot mikes means that the piano appears honestly sized in the mix, which means its physical presence can easily get overwhelmed on record—something that doesn't happen live, even if you're seated well back in the hall. The NHB-458s managed a particularly believable, properly proportioned apparition of the piano, with an ideal balance between the hammer attack, the soundboard sustain, and the decay into the hall acoustic. A harder-sounding amp would accentuate the attack and probably shortchange the contribution of the soundboard; a softer-sounding amp would communicate the soundboard's warmth, but miss the piano's percussive qualities.
 
The NHB-458s nailed that record, as it did Wilkie's recording of Vladimir Ashkenazy and Georg Solti performing the Beethoven piano concertos with the Chicago Symphony (LP, Decca SXLG 6594-7)—another set that would sound good on a boom box. Through the NHB-458s, the piano's textural and tonal clarity and physical focus were a few significant steps better than what I've heard from the other amps mentioned.
 
Could the darTZeels rock? With that much power, you'd think their dynamic possibilities would be unlimited. You'd be correct. What's more, the more I cranked them, the better they sounded. They never got hard or brittle, but seemed to always sound . . . just right. XTC's superbly recorded and mixed masterpiece, English Settlement (2 LPs, UK Virgin), has sounded spectacular ever since the first time I played it, through Spica TC-50s, in 1982. Through the NHB-458s, it sounded so good, and so much better than I'd ever heard it, that I laughed out loud. Track 1, "Runaways," is a densely packed, chant-like track with an impenetrable overlay of jangly guitars anchored by thundering bass drum and thick, undulating bass guitar. The NHB-458s reproduced the bass line with an ideal mix of control and textural elasticity, to give it the desired "sticky" feel, in front of which the curtain of jangly guitars sat well forward, spatially farther separated from the bass parts than I can ever recall hearing, and so fast and precisely rendered! If you love this album, as I do, I wish I could sit you down and play for you "Yacht Dance": so delicately drawn, yet so three-dimensional and so physically solid. The handclaps had never sounded so well fleshed out. In fact, handclaps in general, whether on the Beatles' Abbey Road or Mel Tormé's audience at Marty's, had never sounded quite so fleshy or real.
 
The new vinyl reissue of Paul Simon's masterpiece, Graceland (LP, Columbia/Legacy), was cut to lacquer (as opposed to DMM for the 1986 release) from the original analog tape by Ryan Smith at Sterling Sound, who learned the trade from veteran George Marino. This LP demonstrated everything great about the NHB-458: "rapid response" speed, dynamics, transparency, tonal and textural finesse, and, especially, soundstaging. The amp's ability to cleanly and transparently layer instruments in three-dimensional space was superior to anything else I've heard.
 
In "Diamonds on the Soles of Her Shoes," Ladysmith Black Mambazo's opening chant, split between the channels, attained a hair-raising level of transparency and three-dimensionality, while the drum thwack that introduces the melody exploded from the left channel with alarming power and textural suppleness. As the "ta-na-nas" faded out at the end, everyone who sat and listened, from manufacturers to friends to John Atkinson, and without exception, exclaimed, "Wow!"
 
Caution and Zeel Listening
After a few weeks of happy—no, ecstatic—listening, the Wilson MAXX 3s were wheeled out to make way for the Joseph Audio Pulsars, which I reviewed in June. The NHB-458's manual includes enough cautions about connecting and disconnecting speakers and preamps to give me pause about the amp's robustness and stability in the event of, say, a shorted speaker cable. Before disconnecting and connecting cables, you're warned to shut off the amp, disconnect the power cord, and wait a few minutes. Because of the NHB-458's power reserves, lethal voltages can be present at the speaker terminals. which partly explains the cautions.
 
Nothing I substituted for the NHB-458s came close to approaching their spectacular sound. When the NHB-458s once again powered my system, sonic bliss returned—not that the other amps had caused any suffering in the meantime.
 
At Delétraz's urging, and because I own one of his NHB-18NS preamps, I had substituted his 50 ohm, BNC-terminated, coaxial Zeel interconnect for my TARA Labs Zero. I don't have the space here to discuss transmission-line theory, or why Delétraz believes his Zeel connection is superior to any standard interconnect, especially in terms of eliminating electrical reflections. (Years ago, before he began making amps and preamps, he wrote a paper about this for Stereophile's November 2001 issue—also see this article.) In any case, the relatively inexpensive Zeel cable connection took everything I've described above to an even higher level of clarity, dimensionality, and harmonic and textural purity.
 
Conclusions
If you've already concluded that the darTZeel NHB-458 is easily the finest power amplifier I have ever heard in my listening room, you're correct. It combines lightning-stroke overall speed, effervescent and precise high-frequency transients, and unlimited dynamic capabilities at both the macro and micro levels, with supple and delicate yet powerful bass, and transparency that surpasses anything else I've heard at home. And it does all of that without sacrificing any of the harmonic riches and/or textural performance that speedy amps usually jettison. There was nothing cool, clinical, or analytical about the utterly transparent sound produced by the NHB-458s. Nor, after months of listening, could I detect any obvious coloration's or artefacts.
 
If you're fortunate enough to be able to afford a pair of these amps and you're not a single-ended-triode guy driving big horns with a few watts, you should hear a pair of NHB-458s in your system
The rare handful of incredibly well-heeled audiophiles who can afford this masterpiece will be buying a true audio legend. I’m jealous. I really am
Alan Sircom
The first thing you notice about the NHB-458 is their sheer physicality. The chassis itself is not much larger than an Apple Mac Pro or similar tower computer. Except it weighs as much as a truck load of Apple Macs and is made out of solid aluminium billets that take 150 hours to machine before sent for some of the richest anodizing around.
 
Yet, for all that endless dynamic range and ability to go from mild to wild as fast as the music played, it’s not just about dynamic range. It’s a surprisingly subtle amplifier for something that vast.
 
What the DarTZeel goes for is the musical enjoyment and entertainment first and foremost, and it does that through the dynamic freedom of having almost instant, almost total power. Playing Goodbye Pork Pie Hat on Mingus Ah Um, you get to hear this in the way the sax is there, living and breathing in front of you. It will bring out the majesty in music, even if that majesty is not easy to find.
Sometimes a product just demands a large gasp. The NHB-458 is once such product, the weight, the physical size, the finish, the power on tap… and the price tag are all gasp worthy.
 
In a way, the NHB-458 is a sign of just how good the first DarTZeel product – the NHB-108 stereo power amp – really is. This 100 watt stereo chassis is one of the best amplifiers you can buy. To improve upon it is not easy – simply making bridged mono versions of the NHB-108 doesn’t cut it – it would potentially improve upon the stereo chassis, but not provide the same jump in performance the 108 has above its peers. To make an amplifier that was demonstrably better than the NHB-108 without losing something in the process was the motivation behind the NHB-458 monos. And it goes some way to explain just why these things cost so much; it’s not two NHB-108s, it’s more like the exponential of the power amp.
 
The first thing you notice about the NHB-458 is their sheer physicality. The chassis itself is not much larger than an Apple Mac Pro or similar tower computer. Except it weighs as much as a truck load of Apple Macs and is made out of solid aluminium billets that take 150 hours to machine before sent for some of the richest anodizing around. The distinctive gold and red colour scheme used in other DarTZeel products gets its full expression here, and it looks more elegant in the flesh than it might first appear. Two smoked glass side panels show off what’s going on inside the amp.
 
In fact, like the NHB-108, what’s going on inside the amp is deceptively simple. No contacts, no switches and just a single gas-filled relay per side. No negative feedback in either input or output stages and only three junctions in the signal path from input to input. As you might expect from so expensive an amplifier, it involves a lot of astoundingly expensive components and incredible amounts of power reserve, and a custom-made toroidal transformer about the size of a car tyre. Which is why the amplifier weighs so much, and why a notionally 400 watt per channel amplifier tops out at something closer to 1.4kW at full tilt.
 
The exciting thing about a pair of power amplifiers built to such a high specification – and at such a high price – is it immediately side-steps all the normal limitations and considerations about context. Someone spending the price of a new Mercedes Benz SLS AMG gullwing coupé on a pair of power amplifiers is not going to be limited in their choice of source component, preamp, loudspeakers, room, room acoustic treatment, stands, tables and cables. This is always going to be partnered with the very best, so discussions of compatibility seem at best pointless. 
Nevertheless, there’s a natural partner in the DarTZeel NHB-18NS preamplifier and Zeel connections. The rest is expected to be of a similarly high calibre.
 
Suitably partnered, the experience is a remarkable one. Although its capable of playing the sort of nice, safe music usually heard at hi-fi shows, it’s hardly a test for an amplifier this capable; the NHB-458 is the kind of amplifier that’s wasted on simple music and can take anything you throw at it.
 
That being said, at first you should handle with care; not because it’s fragile, but because this kind of dynamic range is not usually found in audio equipment and you might suffer because of it. This is the audio equivalent of a classic Lamboghini Countach. Hit the throttle (or in this case, the ‘pleasure control’) and hang on to something. Waaaaaaaaaaarrrrrroaaaaaaarrrrrrrggggggghhhhh! This isn’t just a dynamic-sounding amp, it’s a dynamic amplifier with a supercharger, nitrous oxide injection, twin warp engines and it’s own particle accelerator. All those years with CERN built under the Alps patently rubbed off on the Swiss, and this is the sort of amp that can go from a fraction of a watt to picking loudspeaker drivers out of the wall in an eyeblink.
 
And like an old Lambo, this unlimited power at your fingertips comes with responsibility demands upon the listener. As it warms up, it’s twitchy before it is responsive. But even when it’s at full throat, you need to handle with care; there’s no single happy place volume level, you need to fine-tune each record or you’ll overload. That’s not the speaker or the room overloading, and it’s certainly not the amp, but you. You can’t take the information overload.
 
This is perhaps an example of how audio should be. Each recording has its own level and if you like to play these at something approaching real-world levels in the listening room, you have to act like a bit of a safecracker at the controls. Yet, for all that endless dynamic range and ability to go from mild to wild as fast as the music played, it’s not just about dynamic range. It’s a surprisingly subtle amplifier for something that vast.
 
Vast, and fast. It’s virtually psychic. Transients like rim-shots appear with a directness and impact that makes almost everything else sound like it’s got a ‘thing’ against drum kits. And yet, the amps are some of the most sweet and relaxing amps around. And for all that, it’s not the sort of psychotic sound that tries to be all things to all people, and ends being nothing for anyone.
 
 
What the DarTZeel goes for is the musical enjoyment and entertainment first and foremost, and it does that through the dynamic freedom of having almost instant, almost total power. Playing Goodbye Pork Pie Hat on Mingus Ah Um, you get to hear this in the way the sax is there, living and breathing in front of you. It will bring out the majesty in music, even if that majesty is not easy to find.
 
There’s a lot of the sound of the original DarTZeel stereo power amp here, just with seemingly endless power. The speed, the harmonic richness, the sound of an amp getting out of the way were all functions of the original stereo. They are just here in full effect; where the stereo chassis hits its functional limits of dynamic headroom, sheer driving power for big speakers and big rooms and stereo separation, is where the monos begin to let their hair down.
 
We are all children of the soundbyte today. Everything needs to be pinned down in a pithy sentence, no matter how much that trivializes matters. The DarTZeel soundbyte works, though – it’s a flea-powered amplifier that brought a really big friend along. This has all the romance, dynamic freedom and sparkle of a three-watt triode design coupled with the sort of effortless power delivery you might expect from a kilowatt design. From a sonic perspective alone, this is the Bruce Lee of amps; light and deft on its feet, but capable of kicking you through a door seven times in a single second. You don’t just listen, you hang on. It’s a rush, it’s a hell of a ride!
 
Let’s ‘man up’. There’s no getting away from that price; can any power amplifier, no matter how good, be worth more than a top Porsche Panamera Turbo with all the trimmings? In some respects, the question is an invalid one - you aren’t going to splash out six large on an amp without having a heck of a lot of wealth behind you. If you want the most majestic sounding, most romantic, most musically beguiling sound yet produced, but with lightning quick reflexes and the sort of dynamic range that will leave most speakers feeling like they went ten rounds with a before-the-griller George Foreman, this is the place. And if you have the folding to make the price question irrelevant, you’ll buy it. And I envy you, for owning something that passed fleeting through my fingers (except weighing as much as the amps do, they wouldn’t pass through fingers, they’d tear a few off in the plummet to the ground if you tried such a thing).
 
In all bar my wildest fantasies (OK, not those fantasies; the printable ones), there’s no way I could ever dream of even thinking about affording this product, despite sprinkling the most special reviewer magic pricing dust over the NHB-458. But if I could, I would. The rare handful of incredibly well-heeled audiophiles who can afford this masterpiece will be buying a true audio legend. I’m jealous. I really am.
If you're in the market for a state-of-the-art preamp or just want to hear the results of one man's lifelong passion and brilliance, track one down and listen to it.
Mike Malinowski

Summary review:  
....you cannot go wrong with the 18NS. In fact, if you don't need complex control functionality, you'll be in heaven with the darTZeel. I bet that for many, it will be a lifetime purchase. It is that rarest of breeds, a revolutionary state-of-the-art preamp that breaks new ground with its design, execution and performance. If you're in the market for a state-of-the-art preamp or just want to hear the results of one man's lifelong passion and brilliance, track one down and listen to it. Highly recommended. 

Extended review:
Introduction
The darTZeel NHB-18NS (Never Heard Before - model 18, No Switches) is Hervé Delétraz's all-out assault on the state-of-the-art of preamp design. At NZ$47,995 (incl phono option) it better not be a me-too product. The most common reference path in preamp design is to combine superb sonics with über-control flexibility. The two-chassis VTL 7.5, Boulder 2010 and Levinson 32 all take this course. These are amazing beasts that can adjust levels, select inputs and in the case of the Levinson, vary the resistive and capacitive loading for your phono cartridge – all from the comfort of your listening chair by remote control. These are no sonic slouches either.
 
Hervé has taken quite the opposite approach. While not calling the 18NS minimalist, there is certainly no vibrant digital display, no multi-function remote control nor dozens of buttons and switches to be found anywhere. This baby was designed for one thing: to be the finest sounding preamp anywhere at any price. This is one man's lifelong commitment to produce a sonically spectacular device with revolutionary design elements using common off-the-shelf parts, then build it in Switzerland to a standard that should allow it to outlast most of us.
 
With a build quality that is off the scale, the 18NS has a stunning look that is unique, simple and elegant. One button, two large knobs, and three lights are its prime distinguishing characteristics. The 18NS was designed to be the companion piece to the NHB-108 amp and shares the sonic darTZeel family sound. Far more than sharing just a physical appearance, the circuit design of the 18 is virtually identical to that of the 108. It's fair to say that if you like the 108, you'll love the 18 - and let me tell you, I loved the 108. Hervé is an engineer and designer who truly understands the purpose of musical enjoyment. With unmatched zeal and fully understanding that an amplifier will not cure cancer nor end poverty, Hervé's purpose was not for an edifice to his engineering excellence but to bring ultimate joy and musical pleasure to the listener, with a slight added touch of mischievous whimsy. Did I mention that the 18 includes a superb built-in phonostage? It most certainly does.
 
Although grossly oversimplified, the darTZeel philosophy is:
 
(1) Use an exceptionally simple amplifying circuit.
(2) Remove all global feedback and virtually all local feedback.
(3) Provide perfect power.
(4) Design the circuit for exceptional extended bandwidth and minimal phase shift.
(5) Eliminate all switches, relays and traditional volume controls.
(6) Build it to a quality level that would make NASA proud.
 
This in essence defines the 18 NS.
 
Description
 
If you are expecting dozens of controls, knobs and switches for your $20K, then you might be disappointed. The most obvious physical characteristics of the 18NS are two large knobs, symmetrically placed on the front panel, which compare physically to the power lights of the 108 amp. The left knob called Enjoyment Source is the input selector. The right Pleasure Control knob is what most others call a volume control. Both controls have rubberized bands around the circumference and a silky elegance that you must feel to believe. The center on/off button is called the Power Nose (again identical to the 108 amp).
 
While the 18NS visually matches the 108 amp, I can assure you that it will match nothing else on your equipment rack. No one will mistake this gold and red beauty for any other brand. It's not going to blend in with your other silver and black components but who cares? This sucker was built for sound, not to blend in. Don't get me wrong though. While the unit is visually different, it really is stunning. If colour or style matching are your prime concern, however, there are certainly other routes to go.
 
This is one heavy piece, weighing 23 kilograms (50 lbs) with 16mm (.63 inch) thick front panels, 10mm (.4 inch) side panels all evidencing fanatical attention to milling and construction. This is obviously a no-compromise component which was not made to a price point. It is elegant and sophisticated in design, meticulous in execution.
 
The rear panel
 
Unlike the simplicity of the front, there's a little more going on in the rear. In addition to the standard single-ended RCA and balanced I/Os, there are fourteen 50-ohm connectors which darTZeel calls Zeel inputs and outputs. More on this later but they are an important element relative to Hervé's vision of sonic perfection.
 
A small toggle switch below each input allows switching between various grounding schemes if you run into hum problems. Select either chassis ground, earth ground or floating ground. Line inputs one through five are switchable between single-ended or Zeel inputs. A small toggle switch below each selects between single-ended, Zeel or a 6dB attenuation setting. Input number six is for XLR balanced sources with a switch toggling between standard 600-ohm impedance for professional gear and 6dB attenuation. Another switch offers various grounding paths for minimizing ground loops. Standard outputs include balanced XLR, RCA, a single buffered recording output and three buffered Zeel outputs which, with optional filters, can be used to feed the 108 amplifier for either bi-amp or tri-amp applications.
 
Remote control
 
You can't get much simpler than the 18's remote, machined from a solid billet of aluminum. It's heavy and well-balanced but really does only a few things: raising and lowering the volume, full muting and turning the front face panel indicator lights on and off. The design is minimalist squared. If you're looking for a remote to control the universe with like the VTL 7.5, look elsewhere. Because the 18 doesn't have digital readouts, pressing volume up or volume down causes the three fascia indicator lights to momentarily flash green, indicating that the unit is receiving volume change instructions from the remote, a neat little feature. As to input source changes, Hervé's philosophy is that if you're going to change a source -- from phono to CD let's say -- you have to get up anyway to cue the record or load the CD.
 
Design
 
According to Hervé, the fundamental problem in amplification is transient intermodulation distortion (TIM) which occurs "when the negative feedback loop is in a state of overflow which is something that arises more often than you might think since a negative feedback loop correction always applies after the phenomena to be corrected appears. During these very short instances, the amplifier can produce more than 100% THD and/or IMD." In darTZeel speak, this is temporal distortion. The other contributor to temporal distortion is phase shift, especially at very low and high frequencies. Hervé challenges listeners to look at a square wave response of an amplifying circuit at, let's say 40Hz, not just at 1k or 10k. Although a square wave at 40Hz might have an excellent rise time, significant tilting at the top indicates problems. "Ideally the amplifying circuit should reach 10 times lower and 10 times higher than the audio band to maintain correct phase. Our circuits extend 50 times lower and 50 times higher... at 20Hz we are quasi flat ... at high frequencies we extend to about 1MHz - 50 times more than 20kHz to obtain 1° phase shift at 20kHz."
 
According to darTZeel, eliminating phase shift and global feedback solves the temporal distortion problem. Therefore, all darTZeel amplifying circuits operate only with small local negative feedback loops instead of a global loop. It is an interesting academic solution in theory but apparently difficult to execute in practice. High bandwidth generally requires global feedback, and low feedback equals poor frequency response. It's taken Hervé 20 years to develop and perfect his solution and the interview following the review will shed some light on specific design implementations.
 
Back to the front panel. The only other knob there is a small balance control and like most things here, it is slightly different. There is no audible difference in balance until the balance control is moved approximately 5° off center. When you're close to the center position, the system keeps the channel balance exact. A full turn right or left equates to 3.5dB maximum cut, automatically boosting the opposite channel by the same amount for a maximum of 7dB tilt. This allows for an exceptionally fine tuning of the overall soundstage without affecting the overall volume, permitting utterly precise imaging and balance control.
 
There also are two small spring-loaded switches for mute and stereo/mono. The central front panel LED glows yellow when the preamp is operating in the battery mode and red when charging. The other two LEDs indicate red or green for mute and stereo/mono. There are two small red indicator lights on the enjoyment and pleasure knobs to indicate their relative position. The LEDs are innocuous to me even in a darkened room but can be turned off. A home theater bypass mode is provided.
 
Again, you don't switch an input, you "enjoy a line source". A quick twist of the enjoyment knob allows you to change your enjoyment from one input to another; with about a one second delay and a soft audible click, your enjoyment begins.
 
Battery Power
 
Very few designers have successfully implemented battery power in preamps. I can think of ARS Emitter, Dodd, Edge, Silvaweld and Sutherland in this esoteric realm. Separate, massively filtered, regulated power supplies are now de rigueur in reference equipment. Therefore, one might question the need and trouble for both the designer and the end user to rely on battery power. My current VTL 7.5 and the Levinson 32 are perfect examples with power supplies as large as the amplifying section. They also weigh as much as a small power amp.
 
Many people leave their preamp on continuously to keep it in a ready-to-use state. Preamps draw relatively little power, therefore this is accepted behavior. It does not apply to the 18NS. Its battery power and automatic charging circuit preclude this. The battery system is designed to continually power the preamp as long as the batteries retain a charge. Upon discharge, the charging circuit turns on, the preamp converts to AC power and the LED on the front panel turns red to indicate charging. When the battery is charged, the indicator light returns to yellow in an automatic and continuous cycle. If you leave the preamp powered up nonstop, you'll never know the relative state of charge or discharge. You could sit down for an all-night listening session and the batteries could enter their charge cycle. Instead of listening to battery power, you're then listening to AC. It's not the end of the world. On AC the 18NS is still one of the world's best, it just loses some of the magic. There's a loss of transparency, purity and a slight increase in grain. So just turn the 18 off when you're done. Once it's broken in, it doesn't matter because it has a relatively short warm-up. After five to ten minutes in my informal tests, it's ready to go. Also, leaving the unit on causes a constant cycle of charging and discharging which will shorten battery life. The outboard supply includes the battery charging system and serves as backup power should the batteries expire. Under normal charged-battery listening, the power supply "disconnects" automatically. If you listen while the red light goes red, every minute in red mode means two minutes of battery life. If after 10 minutes of playing while charging you power the preamp off and on again, the machine will play on battery mode for 20 minutes. It means that one doesn't have to wait for a full charging cycle to enjoy battery mode. Battery mode is preferred at every power-on until battery level really needs a charge.
 
Break-in
 
For me, that's a quick terminal cleaning with alcohol, an application of Walker Audio's Extreme SST contact treatment to a few connections, a push of the 'power nose' and we're ready to go. My initial unit was delivered new from the factory and I used the Stereophile break-in CD for approximately 100 hours before any serious listening. Upon initial listening, a minor glitch arose in the unit when the volume control was advanced to moderately high listening levels. After a return trip to the factory, the problem was quickly resolved. Not knowing how much playing time the unit received at the factory, I continued my break-in for three or four days while listening intermittently along the way. The sound of the unit remained consistent during this three to four day break in. The bottom line is that due to the unit's return to the factory, I cannot definitively state the required break-in time. If the 108 amp is indicative, and based upon the similarity of the circuit design, I would recommend a considerable period. There is some ongoing bickering in the audiophile community related to buying megabuck components and then being forced to spend time breaking in the product. Personally, I could not care less. For many people, the darTZeel is a lifetime purchase. Allowing a week's break-in is no big deal. Cars and other mechanical devices have break-in periods and to my ears, virtually all new electronics benefit. Get over it. Worry about important things in life.
 
The sound
 
Let's end the suspense - as if there was any to begin with. I was blown away by this preamp, especially its air and transparency. The sound just doesn't emanate from the speakers, it soars. On Plas Johnson's Positively [Pure Audiophile records], Johnson's tenor sax floats with wonderful precision in the room. Glenn Miller's Orchestra's direct-to-disc [The Great American Gramophone Company] is a challenging record to reproduce; the lightning fast transients, bold dynamics and intense brass of Tuxedo Junction shows off the 18's ability to nail dynamic contrasts.
 
Transient response, a seamless soundstage and a top-to-bottom coherence place the 18NS at the top of the charts. Think electrostatic and Kharma speakers. When set up properly, both produce a most wonderfully coherent and seamless presentation. The 18NS is the electronic component version thereof. The comparison of course is conceptual. I'm not saying that the darTZeel will make your system sound like a Sound Lab or Karma Exquisite. What I am saying is that these components bring a seamless focus to the table. The ability to hear and resolve various instruments in real space without any artificial etch puts the 18NS in rarefied strata.
 
Every amp or preamp in my experience exhibits some degree of smearing, often as the music increases in complexity yet the 18 preserves clarity regardless of the musical complexity. Almost any system can reproduce the first half of Ravel's Bolero [Stanislaw Skrowaczewski, Minnesota Orchestra, Reference Recordings] in its utter simplicity. About halfway through when the strings make their entrance, the wonderful initial eloquence at times can bog down as the ever increasing complexity congests low-level detail. When the horns enter, the chaotic crescendo can leave many components in the dust but the 18NS keeps consistent focus and resolution with zero stridency.
 
Transparency, Clarity and Resolution
 
By no small margin, the 18NS is my personal champion in the resolution arena. It offers remarkable transparency. When it comes to coherence, detail and resolution existing within an extraordinary musical framework, the d'art is in a class by itself, revealing the source with no definable euphonic coloration. It's one thing to extract detail from a small jazz ensemble; quite another for a full orchestra. Playing with the delicacy that is the "Meditation" by Jules Massenet from Clair de Lune [Raymond Agoult, London Symphony Orchestra, Classic Records], all sensuous and soothing, the 18NS provides a wonderful balance between micro-dynamic clarity and liquidity.
 
The Brazilian sleigh bells in Hi-fi A La Española [Fennell, Eastman-Rochester Pops, Mercury] are light and airy, displayed with precision and perfect musical balance. I've heard them too soft and round and at other times harsh, grating and sterile. The 18 gets it just right.
 
Don't confuse the fundamental difference between clarity and apparent clarity. To use a video comparison, turning up the video sharpness control might have the appearance of more detail but in reality it obscures the smallest details. This is provable by test patterns and by people far more knowledgeable than me. In the audio analogy, the 18NS defines the difference between clarity and apparent clarity.
 
As a personal favorite and challenge to the system, Nat King Cole's Greatest Hits [DCC] is an amazing record, especially realizing that the music was originally recorded 40 to 50 years ago. It offers wide dynamics and -- when all the gods are in alignment -- a spooky, eerie in-room presence. With "Orange Colored Sky", the brass is right on the very edge of harshness and slightly aggressive. Played with sub-par components or misaligned VTF/VTA, you will quickly cover your ears to hide. Go too far the other way towards warmth, lushness and tubiness and you get dull, boring, and overly sweet. The darT nails this one too.
 
Some components can flesh out a vivid soundstage but have a somewhat fuzzy indistinct area between the individual instruments. The overall soundfield might appear exact but not real when compared to live music. This diffuse nature in defining the air around the instruments betrays the music as a reproduction. Whether it's the extended bandwidth, solid phase response or some other design criteria, the darTZeel preamp and amp are clearly in a class by themselves when it comes to fleshing out the air and distinct area between instruments.
 
Every high end manufacturer aspires to build components to convey the sound with a minimum of electronic artifacts. Excluding the theoretical "straight line with gain", every electronic device unfortunately has a character and therefore, artifacts. You might like them and they may sound good to your ears, but they impart electronic characteristics different from the original music. Don't kid yourself, the 18NS will not magically allow an orchestra to appear life-sized in your living room either. What it will do is strip away more of the artificial nature of reproduction, allowing you to get lost in the music with a deep emotional immersion. There is a purity of timbre that favors neither the bass nor highlights the treble. It just has the tonally right feeling of beautiful music. The 18NS simply reduces the artifacts present in most reproduced music which sends audible clues to your brain that you are listening to reproduced music, allowing the music to appear relatively more alive.
 
Soundstage
 
The 18 is forceful without the slightest hint of strain. With Dave Brubeck's Take Five, Time Out [Dave Brubeck Quartet, Classic Records] lesser components tend to compress and dampen the dynamic moment of impact when the drums literally explode into the room. Leading edges are softened and trailing edges are at times compressed. Not so with the darts; the drums literally detonate into the room with startling realism.
 
The 18 scales beautifully from Oscar Peterson's small trio on West Side Story [DCC] to Wagner's Ride of the Valkyries, Die Walküre [Eric Leinsdorf, Los Angeles Philharmonic, Sheffield Labs]. Size is properly maintained. On one end of the spectrum, Peterson's Trio is
not overblown with 10 foot-wide saxophones nor is the Los Angeles Philharmonic compressed. Each is presented in a very natural, precise soundstage. In both instances you can close your eyes and imagine the instruments reproduced with their various intensities with tonally right harmonic characteristics. Another lovely test passed with ease is Mussorgsky's Night on Bald Mountain [Leonard Maazel, The Cleveland Orchestra, Telarc]. From a single haunting violin, through massed strings to a crushing crescendo, this recording will tell you a lot about your system. Once again, the darT acts as essentially a massive pipe allowing the music to flow through unaltered.
 
Bass
 
My first casual reaction to the darTZeel was that possibly the frequency response was tilted ever so slightly upward with a slight lack of bottom end impact. But then there is a reason reviewers get paid the big bucks. It's for the long-term critical evaluation of components using a variety of sources, not for snap judgments. And over the long haul, it became clear that the 18 did not add or subtract anything. It just revealed.
 
The bass is distinct, taut and focused, painted not as a single homogenous note but with far more complexity. The sound of the drum from the initial thwack changes and envelops you with a startling top-to-bottom clarity and purity, exceeding every preamp in my history including the magnificent VTL 7.5. This clarity is manifested by the revelation of minute details and nuances buried in the musical event.
 
Although the bass is as tight and delineated as I've ever heard in my system, it does not have the greatest perceived slam. Hervé hypothesizes that amps with temporal distortion and phase shift cause artifacts that produce large and boomy bass. Hervé cautioned to judge the bottom end based upon the tautness, definition, control and depth - not the perceived amplitude.
 
If you want clean, loud and deep, this baby loves being turned up. The 18 can rock out with the best of them. "Heartbreaker", Led Zepplin II [Classic Records] which can sound a touch thick, came through crisp, clean and lightning fast. As I mentioned before in my speaker analogy, the 18 shares some characteristics with electrostatic speakers. I fondly recall my Acoustat 2+2s and I referenced them several times in my listening notes. The 18's speed, detail and cohesion bring me back to memories of the Acoustats but with a far more natural midrange (no plasticity), and with a bottom end far deeper and tighter than the Acoustat could ever dream of (of course now I listen to Wilson Alexandrias too).
 
Highs
 
At the other extreme, the darT presents a wonderful top end that seems to extend, well, forever. Bells, cymbals, chimes are rendered with a shimmer and ethereal beauty, which floats in space and cuts through the other instruments, ultimately fading with a wonderful decay.
 
We have all heard components with extended highs presented with somewhat of a hardness or texture. Not so with the darTZeel. The 18 renders highs with a total lack of grain, analogous in video to a switch from a standard analog video signal to 1080P HD.
 
Imaging
 
Imaging is life-sized and definitely not overblown, with a soundstage that does not slam you with an in-your-face presentation. While it does extend out from the front plane of the speakers and deeply behind the speakers, it does not throw the listener into the sound field as some components do. The darT presents the music to the listener, it does not immerse the listener in the musical stage. At times, some components can present an exaggerated sense of height. Ella Fitzgerald appearing fifteen feet tall might be exciting in a hi-fi sense but not realistic. The darTZeel nails this perspective perfectly with images scaled very realistically.
 
Transients are razor-sharp and well defined which in my experience leads to wonderful PRaT (Pace Rhythm and Timing). This speed and resolution allows you to hear many subtle details previously buried in the mix. As a person
been blessed with a high resolution system, I never imagined at this point in my listening career that I would be re-discovering detail and information from sources which I have heard dozens if not hundreds of times. Yet in the past few years, it has happened three times: with the Walker turntable, the Wilson X-2 speakers and now with the DarTZeel amp/preamp combo.
 
The darts display a fascinating characteristic which I often find in live music - the ability to focus either on only a specific instrument (or group of instruments), or to defocus and absorb the performance as a whole. The theory is that specific brain cells retune themselves to specific sounds and adapt to make a sort of feedback process for auditory focus. Whatever the explanation, I really enjoy this phenomenon and it allows me to listen to music on several levels. Sometimes I want to listen to the individual instruments, melodies and rhythms; at other times I just zone out and listen to the overall musical experience. I find the ability to do this far more often with live music vs. reproduced music yet with the 18, it's pretty easy to choose my focus.
 
Phono
 
I have been fortunate to hear some great phono preamps both in my system and in other high-resolution setups. The list is among the Who's Who of great designs - Aesthetix, Manley Steelhead, Lamm, Levinson Reference and even my old Krell, which if memory serves me correct was a spectacular value for the money and highly underrated. There are certainly other contenders in this elite class: the Connoisseur and Boulder come to mind. For me the Walker Reference sits as my current preamp of choice. Two logical questions are, how does the 18's built-in phono sound in an absolute sense and how does it stack up to the competition? The first question is easy. Every sonic description about the preamp applies to its phono input as well: dynamics, spectacular detail, ultra quiet backgrounds and an almost unbelievable lack of grain. Without repeating everything, suffice it to say that if you like the 18NS as a line stage, you will like the phono section - guaranteed. They are obviously cut from the same sonic fabric.
 
How does the phono stage compare with the best? Based on my experience, some general observations. I find the Lamm to be an exceptional and first-rate musical component but just ever so slightly dark. Although the Steelhead offers unmatched flexibility, the Lamm exceeds it in liquidity and emotional involvement. The tubed beast, the Aesthetix, is flexible, dynamic and blooms naturally into the room. When I heard it however, it was not the final word in low noise, although I have not heard the most current upgrade. The Levinson Reference, while good, is frankly not quite in the same league as the others.
 
Fortunately I was able to compare the Walker and darTZeel phono sections. In my review of the Walker reference preamp, I asked "Does the music touch your soul? Are you emotionally fulfilled after an evening of listening? Are you drawn into the music? Is your body filled with goose bumps? These are what matter most to me." My answer was that the Walker delivered these above and beyond the competition. During the past several years, Walker has not stood still with phono preamp design. My unit has been modified approximately four times during that period. The improvements were not minor and in a head-to-head comparison, I still prefer in the Walker slightly over the DarTZeel. This is not a criticism of the darTZeel's performance but more of a tribute to Walker. It just delivers a little more of that musical magic that keeps one enthralled. Admittedly, the comparison is rather unfair since the Walker as a standalone phono preamp costs over $12,000 - without a line-level preamp. As to the others, moving back in my aural memory, I would rate the entire DarTZeel slightly above the Lamm for its amazing resolution, dynamics and continuity. [At the time of publication, darTZeel's fact-check session informed us of a running upgrade to the phono section. Maintaining the same phono sound signature, S/N ratio has been improved by 8dB and 2 transistors were removed from the signal path. Quipped the designer, "of course this update does not invalidate the current phono stage, it's just a small step toward the logical quest for the Holy Grail..." - Ed.]
 
What's the deal with Zeel?
 
Let's take a little detour from the subjective review to examine another one of Hervé's unique design elements built into both his amp and preamp - the Zeel connections. With the hundreds if not thousands of types, brands and price points in high-end audio cable, why does darTZeel believe that we need a new incompatible interconnect system? Further in the mysterious world of cables which have both legitimate manufacturers and a touch of snake oil, what makes darTZeel different? The answer is some pretty interesting science. I will leave it to the engineers in the audience to explore the subject farther but I shall offer a layman's overview.
 
During his early days in design, Hervé became intrigued with cables though not necessarily from an aural perspective. While he clearly heard differences in design, his fascination really stemmed from his inability to correlate design differences with the ultimate sound produced by the cables. Through his research at the Engineering School of Geneva, Hervé tries to solve this riddle. His research and analysis are above my understanding so bear with me in this rather simplified overview of his work, leading to the development of the Zeel connection.
 
Before we get started, a couple of basic definitions on impedance and resistance: Resistance is used with direct current, defined as equaling voltage divided by current (R = VD/C ÷ A D/C). Impedance is the alternating current equivalent of resistance (Z = VA/C ÷ A A/C), with both resistance and impedance measured in ohms (Ω). The primary difference between the two is that impedance varies with frequency.
 
Virtually all modern audio equipment uses low impedance sources and high impedance loads. When this input ratio is ten or higher, all is well, meaning that for example the CD output stage will have no problem driving the input of the preamplifier while offering maximum voltage transfer. However according to Hervé, this universally accepted ratio of ten ignores the inherent electrical properties of the interconnect cable.
 
Hervé's experiments concluded that mismatched components and cables change and distort the sound. While at audio frequencies this distortion might be low, it is distortion and degradation nonetheless. If there is a better solution, why induce distortion to begin with? Enter the Zeel connection. Precisely matched inputs, outputs and cables offer pure distortion-free signal transfer. As we move from theory to application, the first question is whether it works. Is there a difference between a Zeel connection and a high quality interconnect and could the relatively inexpensive 50-ohm Swiss cable be a giant killer? Well, the sound through the Zeel connections and cables closely matches the theoretical predictions of Hervé. At the low end, the bass seems slightly less forceful through the 50-ohm cable but far more delineated and focused. The other end offers an even more dramatic change. The extension, detail and purity of the highs through the Zeel connection yields a far clearer and cleaner overall presentation.
 
Donald Fagan's Morph the Cat [Reprise Records] is a superb reference disc. Although I find the music to be highly derivative of his earlier work, sonically this disc soars. Dynamics, deep clean bass, extended highs and vocals - it's everything that you need to give your system a test drive and the Zeel connections delivered it all. A delicate chime on side 4 is clearly present, with just a wonderful presence and decay. Yet with the VTL, it was far more deeply buried in the mix. When the 18NS and the 108 amp are connected with the balanced Transparent cables, the overall sound of the DarTZeel system sounds -- that is the amp and preamp -- slightly more "traditional" than with the Zeel connections. I cannot overstate this. If there never was a Zeel connection, I could be happy with the 18 forever using traditional interconnect. The Zeel connection simply raises the bar with a touch of extra purity, clarity and definition.
 
Drum roll please: The darTZeel NHB-18NS vs. the VTL 7.5
 
My source is of course the Walker Proscenium Gold turntable recently upgraded to Black Diamond status. The signal starts with the Clearaudio Goldfinger cartridge through Walker's custom pickup arm wiring on to the Walker phono reference preamp. I bounced between Walker's Silent Source interconnects and Brian Kyles' Xtreme Cables from the phono preamp to the darTZeel. The combo is certainly among the top source components around. With this high definition source material, the sonic comparisons between the darTZeel and the VTL 7.5 were actually rather easy. At first I wondered whether two such exalted pieces might have similar sonic footprints, making the comparison difficult. Boy was I wrong. Any non-audiophile raised on Bose would have no difficulty distinguishing between the two.
 
Having lived with the VTL for several years, I know its sound intimately. The ability to switch back and forth between the VTL and darTZeel provided a fascinating comparison. The VTL's soundstage blooms farther out into the room. The 18 exhibits a slightly smaller 3-D soundstage but improves upon the clarity within that soundstage. When listening in the nearfield, the VTL immerses you into the music whereas the darTZeel presents the music to you. The VTL has slightly better macrodynamics, the darT the better microdynamics. The darTZeel extends moderately in front of the speakers, approximately 50% of the forwardness of the VTL, but extends very deep behind the speakers, farther than the VTL. Both preamps present a wide soundstage, with the VTL's ever so slightly broader. The VTL is warmer, with a subtle mid-bass emphasis compared to the 18. Here it gets tricky: while the VTL has apparently deeper bass with more visceral slam, the darT is more defined, tighter and has a clear edge in clarity and air. Although the VTL sound appears deeper, rounder and fuller, I refer you to Hervé's caution in comparing the 18's bass response. Do not get tricked into an initial impression that the 18 lacks in low-end. It doesn't.
 
The crucial midrange in each preamp is smooth, neutral and emotionally satisfying. Again these preamps sound different. The darTZeel wins slightly with its extended highs and that special air. The VTL has a tube-like emotion to the sound while the 18 offers unbelievable resolution. The VTL has a full-featured audio control center while the darTZeel is - well, less endowed. That is assuming six inputs, an integrated phono preamp, recording outputs and three types of primary outputs qualify as minimalist. Do not take these comparative comments out of context. Just because the darTZeel resolves like no other preamp does not mean that the VTL is lacking. And just because the VTL has a luscious 3-D soundstage does not mean that the darTZeel is lacking. Unless you had the ability to switch back and forth between these two in an ultra-high resolution system, you might not draw any of these conclusions. If you are looking for the final pronouncement as to the superior unit, you're not going to get to it from me. At this stratum, both are world-class contenders. When I listen to the darTZeel for an extended period, I am positive it is the one that I want and could live with for the rest of my life. Switching back to the VTL a week later and it could be my long term reference preamp. If you are looking for a definitive verdict, I can tell you that the darTZeel does things especially in the area of resolution and definition combined with musicality that I've never heard before in any component – ever.
 
Summary
 
In my review of the 108 amp, I described the sound as a superb mix of tube and solid-state, probably leaning slightly more toward tube than that of solid-state. It presents music with slightly more tube-like liquidity than even my VTL S400. Interestingly, the 18NS, which has virtually the same circuit design as the 108, would not be mistaken for tube preamp. It really has no attributable sound. It's pretty close to the sound of the Placette Passive Preamp in neutrality but has far more slam, dynamics and that exciting sense of aliveness. Again don't read more into these comparisons than intended. I'm not suggesting that the Placette -- a great passive preamp -- is in the same sonic ballpark as the darTZeel. It's not. However, both are extraordinarily neutral.
 
In the end, if you're going to plunk down NZ$47,995 (incl phono option) for a preamp, you better listen to it. If one is not available locally, get on a plane and find one. When you've reached this level of excellence, you move into the arena of personal taste. If you choose to ignore this advice and your system has the resolving power, you cannot go wrong with the 18NS. In fact, if you don't need complex control functionality, you'll be in heaven with the darTZeel. I bet that for many, it will be a lifetime purchase. It is that rarest of breeds, a revolutionary state-of-the-art preamp that breaks new ground with its design, execution and performance. If you're in the market for a state-of-the-art preamp or just want to hear the results of one man's lifelong passion and brilliance, track one down and listen to it. Highly recommended. 
….. Mike Malinowksi
Should such heady sums be within your reach, you will own a system to rank with the very finest that money can buy.
HomeTheaterReview.com

Summary:
Make no mistake: the NHB-18NS pre-amplifier is exactly the mate for which the NHB-108 Model One power amp has been waiting. They complement each other perfectly, delivering a one-two punch that will knock a hole in the high-end solid-state sector. Admittedly, with a combined price befitting a decent car, you should be getting more than mere amplification, and you do: silky, seductive sound with power to spare. I suppose - were we to follow a car analogy - you could liken this in every way to a modern Bentley: sophisticated, capable of cosseting the owner, yet able to play the hooligan when the pedal is floored. Maybe labelling the volume rotary 'Pleasure Control' wasn't so daft after all.

Extended review:
It's been made clear to me more than once just how privileged I am to receive the actual production version of the long-awaited darTZeel NHB-18NS pre-amplifier for review before anyone else. However obscure Switzerland's darTZeel may seem, it's now a global player in the extreme high end. And the pressure for the scoop review of their first pre-amp ramped up by a factor of 10 immediately after their NHB-108 power amplifier won a brace of awards from our friends across the Pond at Stereophile.
 
According to the distributor, there was a queue of reviewers dying to get their hands on it, they had to fend them off with fears of the sorts of repercussions that follow bruised egos, why Kessler?, yadayadayada. So I suppose my offer to sleep with Serge and Her- no, that's a lie: I earned the privilege because I bothered to fly to Geneva, hang out with the pair, learn about the product and prove my worthiness. The latter might even be due to sharing a common taste in music with Hervé Delétraz.
 
Must've worked, because I've just spent a couple of weeks with the little beauty. No kidding: I do feel privileged. Yup, it's that good. And it' so fresh that it doesn't even have a blank name plaque in the upper right-hand corner; that awaits the engraving of the name of the eventual owner. And having heard the power amp on numerous occasions, I can confirm that - unlike other situations where one part of a pre/power package preceded another, and Part 2 was a let-down - the darTZeel boys followed their debut with a perfect sequel. Think Godfather 2, The Two Towers or Attack of the Clones. Well, maybe not the Attack of the Clones. But you get the drift.
 
As with the power amplifier, darTZeel opted for direct paths and 'heightened minimalism' if such a phrase isn't borderline oxymoronic. As Hervé put it, 'Our dedicated circuits are reduced to their most basic form. As before, there is no application of any overall negative feedback. Because of this approach, the delicate, small audio signals amplified by the NHB-18NS only pass through seven silicon junctions, from input to output. And that includes the 13dB full discrete gain stage. And for the phono stage, we only add six junctions, for a maximum additional boost of 66dB, or 77dB in total.' Their minimalist circuits are currently 'patent pending.'
 
Despite the company's designers suffering an affection for the hideously coloured Rehdéko loudspeakers, they insist that the darTZeel goal is for untrammelled, pure and open sound. Amplifying the low level signals are discrete devices, or matched transistors embedded in dedicated integrated circuits. Hervé again: 'No operational amplifiers are used in the entire signal path. As in the NHB-108, all components used in the NHB-18NS preamplifier, with no exceptions whatsoever, are based on the finest products being produced by leading-edge industries at the present moment.'
 
This is where you start to get whiffs of the Swissness, which requires a brief aside about the 'Made in Switzerland' philosophy. First devised, adopted and safely guarded by the watch industry, that coveted identification of birthright is as closely protected as French wine's or cheese's 'apellation contrôlée', or olive oil's IOOC. darTZeel uses as many Swiss suppliers as possible, partly because the company jingoistically (but rightly) believes that the Swiss are the best at manufacturing anything made from metals, including electronic components, and partly so that darTZeel could become the only audio company to earn the coveted Swiss Label Certificat, attesting to its Helvetian purity.
Those of you who don't share, say, my obsession with Alpa cameras, watches and Nagra tape decks might wonder about the fuss, but - away from ultra-nationalistic Germans and Brits who refuse to believe that anyone could make things as well as they could - any form of proof that your wares are as Swiss as William Tell is akin to the Good Housekeeping Seal of Approval and an Appointment by the Queen all rolled into one.
 
So darTZeel has taken the best ingredients, and formulated a topology that includes the following strictures:
 
There are absolutely no contact or switches nor relay of any kind for source selection, all in the interests of absolute transparency. darTZeel prefers, instead of routing signals through a selector box, to provide each input with its own dedicated gain stage, enabled or disabled according to the user's choice. The signal is then directly routed to the volume control module.
In the NHB-18NS, the volume control module completely avoids the use of any potentiometer, stepped attenuator or analogue switch array in the signal path. According to Hervé, 'The sound signal is attenuated in a fully passive way, within a continuous range of close to 96dB in 192 steps of 0.5dB, in full analogue mode, without the use of any VCA or other active component.
'Both of these breakthroughs constitute a big step in the right direction: no harm to the signal. As mentioned above, this new design is patent pending. As soon as the patents are confirmed, darTZeel will be pleased to describe in detail how such signal treatment is possible.'  More Swissness: they adore secrecy. Just ask anyone who banks with them.
Further in keeping with the NHB-108 power amplifier, the NHB-18NS uses only small amounts of local negative feedback at the inputs, with one small, symmetrical loop of local negative feedback in the voltage gain stages. The output stages are open loop, and free of all negative feedback. 
Within the 440x170x335mm (WHD) chassis is a modular frame, with every stage on a subassembly more like a computer or multi-channel A/V amp than a stereo preamp. Because of this, the unit might one day be customisable to a degree; at present, though, its modularity shows that the unit was designed from the outset to resist obsolescence.
 
Unusually, the company employs its own preferred, proprietary 50-ohm 'darT' outputs and 'Zeel' inputs with BNC connectors, alongside more conventional connections. As shipped and reviewed, the unit features a mix of six inputs covering phono, RCA/BNC and balanced XLR. As standard, these include a phono MM/MC input with gain from 30-66dB, a single 'full-floating' XLR input and four RCA/BNC 50 ohm Zeel inputs. Outputs consist of one XLR full floating output, three BNC 50 ohm darT outputs, ready for tri-amping, with optional built-in passive filters, a pair of RCA outputs and a pair of fixed RCA record outputs.
 
Completing the package, and for many the most important part, is a feature shared by darTZeel's compatriots at Nagra: a battery power supply. Because the NHB-18NS is an 'authentic dual mono preamplifier, from input to output, with separate grounds for left and right channels,' each channel is battery-powered by its own battery bank, offering up to 15 hours of playing time on a full charge. Every input and output is treated to a 'very sophisticated, regulated and dedicated supply, ensuring the lowest power supply impedance possible.' And it's basically set-and-forget: automatic functioning allows full battery operation when listening, with the charging mode activated when the preamp is switched off. As Hervé puts it, 'Hum is gone forever, and there is no need to worry about knowing if batteries need to be charged or not.'
 
'Deliciously simple' described the front panel: source and volume rotaries marked 'Enjoyment Source' and 'Pleasure Control', an illuminated power on button called the 'Power Nose' (examples, I suppose, of Swiss humour), mono/stereo and mute toggles and a rotary balance which lowers one channel by up to 3.5dB while raising the other by up to 3.5dB. The back, on the other hand, is jam-packed. It contains all of the aforementioned input/output combinations and a multi-pin input to accept an umbilical from the outboard charger, along with earth tags for the phono section, toggles to apply 6dB of attenuation on certain inputs, and other toggles to defeat earthing in case of loops.
 
Other niceties include a beautifully-machined remote control for operating the volume; a home theatre bypass mode; multi-coloured LEDs to indicate battery status, charging modes, stereo mode, mono mode, mute, normal, etc.; and useful handles front and rear. The fit and finish are utterly and undeniably beyond criticism. Indeed, the only area one might possibly object to is the choice of gold front panel and red cover. It is, simply put, so frikkin' ugly that even a chav would find it objectionable.
 
But that's irrelevant. Within seconds of switching on, after allowing it to charge up fully, it was blatantly obvious that the darTZeel NHB-18NS goes straight to the head of the class. What we have here is one of those juggling acts performed only by the masters, that heady mix of delicacy and control, sheer musicality tempering almost clinical retrieval of detail, massive scale with no masking of the softest notes. And given its purely solid-state, Franco-Teutonic DNA, the shock is as great as hearing a German tell a joke. One that's actually funny.
 
I wish there were a way to provide a test CD that demonstrates when everything falls into place. It would include a recording that's 95 percent 'there', followed by the same again at 100 percent. Every pursuit has it, whether finding the perfect swing in golf, finding 'the line' on a race circuit, focussing a lens to perfection, burning in just the right amount of crunch on a crème brulée. The darTZeel does this over and over and over again. Even its phono stage, as set at the factory for median value m-c cartridges, obviates the need to look further.
 
Everything about the sound is carefully considered, of a whole, and in perfect proportion. From orchestral to unplugged soloist and every point in between - new, old, mono, stereo, digital, analogue - the darTZeel behaved with the kind of consistency that shrieks pedigree. It simply doesn't put a foot wrong, and even worst-case scenarios - CD transfers of 50s mono vocal discs - failed to reveal shortcomings. This pre-amp treats vocals, male or female, single or massed, with such utter respect that the sheer realism renders other systems artificial-sounding.
 
That stalwart, Keb' Mo', provided both melody and texture that tax most solid-state set-ups, which can never seem to get his rasp just so. They seem to amplify only the harsher elements of it, belying the warmth. Not so the darTZeel: it presented him front-and-centre, tall and noble, the voice a personal command performance, the guitar twanging for real.
 
Trying actively to upset the darTZeel revealed only one caveat: so clean is the sound that you may wish to play it louder than you might normally do, and I did manage to drive the matching power amp into clipping (as evinced by the LEDs). Even then, the clues were stern rather than shocking, and it never sounded like the system was about to implode. You'll be delighted to know that, wherever you dial the 'pleasure control', the scale remains consistent. You'd have to go out of your way to get bad sounds from this. Like hooking up Rehdékos.
 
Then there's the entry fee. Even before you consider the NHB18NS pre-amp at NZ$47,000, you really must consider its sibling, the NHB108B Power Amp, at an equally disturbing NZ$42,000. Should such heady sums be within your reach, you will own a system to rank with the very finest that money can buy. And a mystery, too, will be solved. For those of you who have pondered for decades how the world's premier jazz festival ended up on the shores of a Swiss lake, wonder no more. Montreux: maintenant tout est clair.
 
Summary:
 
Make no mistake: the NHB-18NS pre-amplifier is exactly the mate for which the NHB-108 Model One power amp has been waiting. They complement each other perfectly, delivering a one-two punch that will knock a hole in the high-end solid-state sector. Admittedly, with a combined price befitting a decent car, you should be getting more than mere amplification, and you do: silky, seductive sound with power to spare. I suppose - were we to follow a car analogy - you could liken this in every way to a modern Bentley: sophisticated, capable of cosseting the owner, yet able to play the hooligan when the pedal is floored. Maybe labelling the volume rotary 'Pleasure Control' wasn't so daft after all.
The darTZeel is very close to being my ideal pre-amplifier;
Chris Binns

Summary  
As one would expect of a high-end product of this calibre, it ticks all the right hi-fi boxes, but also makes the important step forward that ultimately cuts the ties that hold so many products earthbound when it comes to letting the music flow. And that, as I suggested earlier, is more important in a pre-amp than any other component in the system. The NHB 18NS is a highly desirable product, and one of the very few that could successfully fill the void left by the Ayre K-1xe, a design that already rearranged my views on pre-amplifiers.

Extended review:
Of all of the components that make up a hi-fi system, experience shows that it is the pre-amplifier that presents the biggest enigma. The task it has to perform is, in theory, pretty straightforward; directing the signal from the desired source component and controlling the volume. Compared to the process of extracting information from the reflective surface of a CD or the groove of an LP, or driving massive amounts of power into a loudspeaker whose job consists of converting electricity back into recognisable audio, it should be a walk in the park. Its not even as if there is any gain needed, as the output from an average CD player is more than enough to drive most power amplifiers into clipping. Hence passives, although in the real world, considerations such as input/output impedance and the capacitance of the cables hinder the attainable performance, while active circuitry provides a degree of isolation and stability against such effects.
 
Why then, am I so often forced to conclude that the pre-amplifier is the defining component of a systems ultimate performance. And, while the limitations of a poor source component or compromised power amp/ loudspeaker combination are relatively easy to identify, the pre-amp often seems to be a constriction or compromise to sound quality that manifests itself in a far more subtle way. Of all audio components, the pre is the one that we expect to be the most sonically pure and devoid of character, adding nothing while acting as the ‘gateway’ for the system that everything else connects to. And the truth is that for all the interesting and highly competent audio equipment I have auditioned in a system at home, the number of truly great pre-amps that have left a lasting impression can be counted on the fingers of one hand. The NHB 108 power amplifier was the first product to appear from Swiss based daRTzeel. A 100 Watt per channel design that was the embodiment of simple, elegant and beautifully symmetrical circuitry, it had a build quality and attention to detail second to none. It also sounded staggeringly good. I was therefore only too happy to have it back while auditioning the 18NS pre-amp, which is built as you might expect, in much the same fashion. Imagine Swiss watch precision applied to virtually every aspect and you begin to get the picture; attention to detail and refinement is the order of the day. Aesthetically the daRTzeel is quite conventional in its shape and mechanical construction, but the metalwork is finished in an industrial red anodising with a mustard gold front panel (which incidentally is much darker than the power amplifier) and I guess this is a look that you will either love or hate – me, I’m making no comment. Further enhancing the ‘glitz’ factor is the gold plated nameplate that you send back to the manufacturer to have engraved with the serial number and your name once you have purchased the unit. Front panel controls consist of a power button, small toggles for mute and mono (hurrah!) and two rotary controls for input selection and volume that are labelled ‘Enjoyment Source’ and ‘Pleasure Control’. A sense of humour lurking under the serious exterior?
 
Internal construction is about as good as it gets, using selected components and no less than twelve input boards on which the connectors in one of the neatest Finally, three multi coloured Led indicators indicate the status and operating conditions of the pre amplifier. The 18NS has four single-ended line-inputs together with one balanced; the RCA’s are duplicated by (darTZeel’s proprietary) 50 Ohm BNC’s and there is a phono input; yep, the darTZeel has a fully fledged phono-stage on board, a trend that seems to be returning. Outputs consist of the usual fixed level tape, balanced and RCA options, augmented by three separately buffered BNC’s specifically for the 108 power amp (the instruction manual talks of incorporating filters for bi or tri-amping at a future stage).
 
The electronic design has a number of interesting aspects and some shared philosophy with the power amplifier. Thus the circuitry employs a simple, symmetrical configuration utilising discrete components (rather than op-amps) where the signal passes through only six transistors in the main gain stage. This delivers an impressively wide bandwidth, claimed to be within 1dB from 1Hz to 1MHz, with no overall feedback applied. Each input has its own dedicated gain stage, which remains permanently connected and is activated when required, thus avoiding any kind of switching in the signal path. Likewise, there is no potentiometer or resistor network in line with the audio, volume control being by passive attenuation governed by a dedicated processor via analogue optical couplers, offering 192 steps in increments of 0.5dB. This leaves the volume knob whirling like a dervish to make any ground, while the remote rather over compensates with sudden lurches up or down. Acceptance angle is narrow but otherwise it is a simple, tactile handset (unlike so many others). For once the balance control is subtle in action, rather than swinging wildly left and right. The phono-stage follows similar design criteria to the linestage, utilising discrete components to provide 60 db of gain, although both this and the loading are internally adjustable using a soldering iron; good for sound, bad for convenience.
 
The darTZeel comes with a separate power supply housed in a small, unobtrusive stainless steel box, although this actually functions as a charger for the 18NS’ onboard batteries. I will confess to initial scepticism; previous experience (now many years ago) with various designs involving re-chargeable Ni-Cads led me to conclude that the complications of using battery power were not worth the lack of reliability and frustration that went with it – not to mention smoke and blown drive units. But things have changed; battery technology has moved on in leaps and bounds over the last few years due to our insatiable demand for mobile technology, and the state of the mains supply is considerably worse, partly due to the rise of switch mode power supplies that are now literally everywhere. The prospect of completely isolating the audio circuitry is now more attractive than ever. Which is exactly what the darTZeel does, once the power switch is activated, relays disconnect the power supply from the internal batteries, which then deliver up to twelve hours listening in this mode. When switched off the unit charges the batteries, and in the event of them being completely flat the 18 will run, with slightly diminished performance, using the mains supply. Not that I was able to investigate this, as a testimony to the effectiveness of the power supply management this was a situation that never occurred, and as with all other aspects of the 18’s operation it performed seamlessly throughout the review. For those of us used to leaving gear powered up, it’s a new discipline having to remember to turn it off after a session, but tellingly I could hear very little difference in quality between a cold start and a few hours of use.
 
It could well be the combination of a number of different but related attributes, but I had an immediate sense of a very clean, transparent presentation with no detectable fuzz or smearing to cloud the leading edges and subsequent body of sounds. And a wealth of detail; not of the “I’ve played this track for years and never heard the drummer fart variety” but more constructive information on note shape and textural qualities that enrich the music rather than distract from it. But I think the most persuasive aspect of the darTZeel has to do with wide bandwidth coherence. I’m convinced that the timing verses frequency issues are an important part of breaking down psycho – acoustic barriers that allow music a more direct connection to the relevant parts of the brain. In other words, the better a piece of equipment is at doing this, the more relaxed I am listening to it and as a consequence less aware of the hi-fi. This particular aspect of performance was highlighted by the Quad 2805 electrostatics, which were far more willing to do the spooky holographic image trick with the darTZeel in the system, often completely disappearing.
 
While the character of the 18NS was essentially neutral, I was always conscious of a very slight sense of warmth to the sound; not in an indistinct, hazy valve-like way but more akin to a slight hint of ‘richness’ that accompanied the music, contributing to a tactile sense of body and substance with natural instruments and voices. Slightly more apparent using the phono-stage, reproduction from vinyl was supremely confident and assured in a way that had me wishing I never had to play CDs again. It majored on flow and involvement over laid bare, concise (and possibly clinical) retrieval of detail that one or two other high-end phono stages are better at.
 
The darTZeel power amplifier allowed me to examine differences between the pre-amp’s three output options. Designer Herve Deletraz has some passionate and distinctive views on cables and signal transmission; hence the unusual 50 Ohm BNC sockets and the matching cables supplied with the unit. Not unexpectedly, these provided the best results with an obvious synergy between the two units: balanced operation via the XLRs seemed sluggish and indistinct by comparison while single-ended connection was considerably better, but still falling short of the custom interface in terms of speed and focus. Using the darTZeel pre and power together proved an awesome combination, but I occasionally felt that it was almost too perfect: perhaps a slightly sickly sweetness that could occasionally have you yearning for a bit of aggression or rudeness with certain music. Can you have too much of a good thing? Maybe, but then both the Quads and the Spendor SP100R are on the polite side. DarTZeel employ Rhedeko loudspeakers for product development – which constitute quite a contrast…
 
Ironically, sometimes the better a product is the less there is to write about it, and after a couple of months spent listening to the darTZeel I am still struggling to define certain aspects of its performance. As one would expect of a high-end product of this calibre, it ticks all the right hi-fi boxes, but also makes the important step forward that ultimately cuts the ties that hold so many products earthbound when it comes to letting the music flow. And that, as I suggested earlier, is more important in a pre-amp than any other component in the system. The NHB 18NS is a highly desirable product, and one of the very few that could successfully fill the void left by the Ayre K-1xe, a design that already rearranged my views on pre-amplifiers. The darTZeel is very close to being my ideal pre-amplifier; one that, like well behaved children, is seen but never heard.
……Chris Binns
Hervé Delétraz Interview with Mike Malinowksi
Mike Malinowksi

Recently I had the remarkable opportunity to combine business with pleasure during a trip to Europe and spend a day meeting with Hervé and Serge in Geneva. This proved to be one of the highlights of my trip. Having never been to Switzerland, I had no idea what to expect. Regardless of your education and experience, we are all saddled with preconceived notions. Mine was the vision of the Swiss as cool, polite and somewhat aloof. Boy was I wrong. Hervé and Serge were warm, open, down to earth and both gifted with a great sense of humor. They welcomed me into their homes and lab and through this interview, offered an insight into their wonderful driving obsession. The conversation bounced between history and technical theory and mixed with some refreshing honesty as you will see. During my various meetings and discussions with Hervé, a single word stood out prominently in my notes: "passion," defined by Webster as intense, driving, overmastering feeling or conviction. That certainly defines Hervé.

Q: Tell us a little of your background and your beginnings in audio.
A: In 1984, I received my diploma in engineering and began to design a digital amp. I wanted to make an amplifier of the simplest possible design. I built a prototype amplifier in 1999.
Q: A digital amp?
A: No. It was the darTZeel Model 0, a big monster - big case but pretty empty inside. I designed it for myself and friends, not as a commercial product. The problem was that my friends did not want to give me back the prototype because of the sound. My friends encouraged me to make a series because the sound of the prototype was that good. So I was encouraged to continue.
 
Q: (to Serge) How long have you and Hervé worked together?
A: I have been part of darTZeel from the beginning, when the first circuit board exploded as I turned on the Variac. Today, I handle sales and marketing and manage other areas. Hervé and I are a good complement. I have total trust in his design genius. On the marketing side, you have to focus all the ideas and imagination to make a product successful. The original amp was built for Hervé personally. He wanted the best for his system. The only purpose was for it to be loved by a listener but eventually it became Hervé's job and he involved me in this adventure. When you translate that to a commercial product, priorities change. You cannot wait 16 more years for a new product. The challenge was, how do you translate the passion to a commercially successful product?
 
Q: What was so special about the prototype?
A: The problem was in fact that I was not worried about harmonic distortion because in instruments, you already have a lot of natural harmonics. Most musical instruments have 20 or 30 percent natural harmonics, so limiting harmonic distortion is not necessary. If you have only 1 percent harmonic distortion compared to 20 or 30 percent of natural harmonics, you don't hear a difference. So my quest for this amp was more for speed, less phase shift and simplicity of the circuit. The new 108 has only six silicon junctions from input to output for the signal path. There is no feedback at all from the output, the schematic is very simple - but it is not simple to make it work properly. I tried for years and finally developed the circuits of the 108 which are patented worldwide because they are, in fact, new designs. No one had a design like this although some might look similar. Now the story of the darTZeel company begins. I showed the amp at the New York 2000 HE Show for the first time. At that time, I had one distributor, Jonathan Tinn in the United States. In a short time, we were distributed worldwide, including Europe, Japan and Asia. It was not easy building this network with one product because the preamp was released much later than anticipated.
 
Q: What about the unusual name?
A: (Serge) The name is an anagram of Hervé's last name, Delétraz (darTZeel). In addition to the meaning, the name has visual impact and creates the image of technology and circuitry.
Q: With the growth of home theater and the decline of two-channel systems, why pursue such a small niche market?
A: We have two ears, two eyes and I think we can pretty well reproduce music with only two speakers. At a concert, the musicians are in front of you, not behind you. You can have the sound reflections which give a rear sound without the need for additional speakers. I do not like rooms with too much absorption.
(Serge) I have known Hervé since we were children because we are cousins. So I can add an explanation. I think that home cinema is associated with TV or visual images and both Hervé and I are aficionados of sound and music. Home theater was originally dedicated to the image first. It is only recently that theater sound is being addressed by the high end audio companies. Our goal is to produce the ultimate in music reproduction. I won't say that we will never make a multi-channel system but not today. The sound tracks in movies are at times much exaggerated. However, with well reproduced music, you just close your eyes and you can feel the experience. For Hervé and me, it is all about the music.
 
Q: Do you design for a particular sound?
A: No! Generally you can associate a sound with a brand. Designers make a family sound but that was not my goal. My goal was to accurately reproduce the musical signal as close as possible. I do not think about making it sound like tubes or transistors. I just wanted to make a good amplifier.
 
Q: Describe your design process.
A: I design first using a computer simulation to make sure that the electronic design works. We then build a bread board prototype. We listen intensely and after we are satisfied, we move to a circuit board and listen again. Listening is the most important part in the design process.
 
Q: Your speakers are unusual. Tell me about them.
A: I love these speakers because they are very unforgiving. They are by Rehdéko, a French brand. It does not exist any more. Its original designer was a real magician. He died since and I really miss him. I know his son and the father who left instructions that after his death, the speakers would stop production. There were many secrets in the manufacturing of these speakers, almost like a Stradivarius violin. The speaker membrane for example is treated with many different varnishes. Many of the varnishes are aged for maybe seven years before being applied. The result is that the speaker membrane is more rigid than Kevlar. The speaker is very fast and slightly aggressive in the midrange. It is amazing. The designer, a musician, wanted to reproduce instruments in the most natural way. So when you hear a trumpet or a saxophone live, it is very aggressive - these speakers are exactly the same. It is not hi-fi sounding, but very musical. They are highly efficient, about 106dB for 1 watt at 8 ohms.
 
Q: Are these the speakers used for your design and voicing?
A: They help a lot in the design because if you have a tiny problem in the circuit, you can easily hear it immediately. They are great design tools, but ultimately, they sound like music.
 
Q: What kind of music do you listen to?
A: Only a small part is classical - I'm too young. But seriously, I like all types, including jazz and rock – old rock groups like Genesis, Pink Floyd, Jethro Tull and the Beatles. I appreciate classical, but it is much more difficult to reproduce accurately. Even with the best system in the world, it is extremely difficult. One hundred musicians playing in natural space, 20 to 30 meters from the audience at full volume is difficult to capture on a recording. Jazz is easier to reproduce. Three, four or five musicians could actually fit into the room so with jazz, you are closer to reality.
 
Q: Once you get to the basic sound you want, how do you tweak the design to meet your goals?
A: Again, we do not particularly tailor the sound to any style. On the power amp, we could tailor the sound. We could, for example, make it rounder. The amp is extremely fast. If we made it a bit slower, you could make it sound more 'tuby'. Depending on the input impedance, you could round the bass but it is not my aim to tailor the sound. I look for accuracy. I will tweak the value of some components however, a higher or lower resistor, for example, to add a bit more current for better speed. The relationship between technique and sound is very close because a good measuring amplifier can often sound bad, but the contrary is more difficult. It is difficult to have an amp that measures poorly and has good sound. There are some, maybe, but it is not easy.
 
Q: What about tube amps, some measure poorly but are very musical.
A: Some tube amps, yes, but I think that with tube amps, if you keep them for two or ten years, you could end up with fatigue because the sound becomes too polite, too round, too smooth. With the 108, we noticed the opposite effect; the longer a customer listened, the more they liked it.
 
Q: Discuss the long break-in period for your amps
A: Reviewers have written that the amp needs a lot of burn in to make real music. Agreed. But I also believe that the listener adjusts to the burn in.
(Serge) I think both the equipment and the listener adjust, especially with the darTZeel. The sound presentation with the darTZeel amp is a bit different than other pieces and you might need some time to get adjusted.
 
Q: How does the circuit design of the new preamp compare to the 108 amp?
A: The circuit design of the preamp, phono section and amp use the same patented design. In fact, the design can be used for any circuit - microphone, preamp, phono or power amp. The schematics are the same, but of course, we don't use the same devices. The amp uses power devices and the preamp, small devices - transistors. We use very low noise matched transistors and there are no op-amps in the signal path.
 
Q: Your designs focus on eliminating what you call 'temporal' distortion. You indicate this as the most audible type of distortion.
A: Temporal distortion occurs when you have phase shift on the bottom or the top. Reviewers might measure the square wave response of high frequencies. I've never seen a square wave response of a very low frequency. Normally an amp begins to show measurements at 100Hz. To have the plateau tilting indicates phase shift. An amp going down to 10 or 20Hz might have an excellent rise time but the plateau is tilted.
 
Q: Is your circuit wide band?
A:The frequency response extends from a few Millihertz. We don't have full DC from input to output because if you have DC at the input, you could have trouble. I have a coupling capacitor but we go very low. So the phase response is very good, even at 20Hz you have excellent square waves. You can hear it! The bass is much more precise. It might appear to be a little lean but that is because it is so precise and so fast. The duration is shorter so it might appear less but it is very clean.
(Serge) People are often used to boomy bass that shakes the room. If you critically listen to the bass driven by a darTZeel, you will hear that it goes very deep but with none of the resonant effects because it is exceptionally fast. Bass with other pieces produces monotonic sound. Our circuit design allows you to clearly hear the individual chords. You will hear far more bass detail with darTZeel.
 
Q: Therefore one of the design secrets to the darTZeel circuit is the square wave response minimizing phase shift?
A: Ideally, the amplifying circuit should go 10 times lower and 10 times higher than the audio band to have correct phase shift. Our circuits go 50 times lower and 50 times higher. Square waves are a very helpful design tool. You can see a lot of things. At 20Hz we are quasi flat; the phase shift is less than one degree at 20Hz. In the high frequency, we extend to about one megahertz - 50 times more than 20 kilohertz to attain about one degree of phase shift at 20 kilohertz.
 
Q: And the effect of this on the sound?
A: In the audio spectrum you are free of any temporal distortion.
Q: There are many amps with wide bandwidth. Some solid state amplifiers with very wide bandwidth such as Spectral and Halcro do not sound anything like your designs. Why?
A: Normally, when you want to reach very high in frequency, you need to use feedback. This, in my opinion, is the holy grail of amplifier design - overcoming the dilemma of high bandwidth requiring feedback and low feedback designs producing low bandwidth. This was the struggle of my design. How do you make a high-bandwidth no-global-feedback design work? The only feedback we use is a small local symmetrical feedback loop for the voltage gain. There is no feedback at all at the output or input. It is extraordinarily difficult to make this circuit work properly so to answer your question, other designers use some type of feedback to achieve bandwidth. I do not and hence the amps 'sound' very different. Also, I use only one pair of transistors as output devices. When you parallel a lot of output devices, you will have fuzziness and you will lose focus.
 
Q: With the small number of output transistors, how do you handle heat dissipation and stress on these output devices?
A: Thermal stress with only two output devices requires a very sophisticated monitoring circuit -- kept outside the signal path -- which can sense actual power dissipated in the devices. The NHB-108 is the only amp in the world to offer 100 wpc (and much more under 4 ohms) while other amps with a single pair usually offer 50 watts at best. Each output device amplifies a slice of the music and the signal might not arrive at the exact same time from all of the transistors, even if they used matched transistors. Two or three pairs can give good sound, but with more than that, it is very difficult to do. The best sound is with one pair. In our future monoblocks we will use two pairs for additional power but to do this I will have to redesign the schematic.
Q: A scoop? Are monoblocks in the works?
A: No, not currently, but they will be in the future. I envision a 300-watt amp but the challenge to keep the same sound will not be easy.
 
Q: Since the circuit is similar for the preamp, I assume the design goals were also similar.
A: When we started to design the preamp, Serge and I decided that the preamp would be the ideal companion to the amplifier. It took time to scale down the amplifying circuits for the preamp. Also, the amp uses no switches, relays or fuses in the signal path. For a preamp, this is much more difficult to implement. You have inputs. How do you implement them without switching? Yet we did it. All of the inputs are selected without switches or relays.
 
Q: Therefore, each input has its own gain circuit?
A: No, although we have a circuit card for each input. We turn on the card when we want to play that input - all without switching. In fact, we apply power to the card using a proprietary light system. The idea was to use light to energize components and with this approach, we can select inputs without the degrading effect of switches or relays. The preamp is completely dual mono. We have two batteries per channel. The grounds are fully separated from left to right and from the chassis. It is essentially two machines in one. The volume controls do use potentiometers for convenience but the signal does not go through it. We do use a resistor ladder, but not in a conventional way.
 
Q: What is wrong with conventional volume controls?
A: You lose something. I use a system that varies resistance with light. However, until all the patents are in place, I would prefer not to specify the details.
 
Q: Visually, the preamp's internal designs look more like a PC than a traditional audio component.
A: It is similar to a computer. Each input has a board but without slots because I don't like contacts. The sound connections for each card are hard-wired. The cards contain the proprietary light switching circuitry which enables or disables the specific input. As with the computer analogy, each card is connected in parallel to the motherboard. There is also one dedicated phono board per channel. We use small buffers with four transistors, the topology being the same as our amp - both sharing essentially the same circuit design.
(Serge) The volume control is a special design that has no tracking error. The worst case is no more than a 0.2dB difference, even better than Levinson's laser trend volume control. In its useful range, we have about .1dB of difference. Again, this was done with standard components, not exotic parts for long term maintenance. The machine can be repaired in 10 or 20 years using standard components. It is possible to make an outstanding machine using standard components. It is just the way you use them.
(Serge) This is a very simple, elegant design that was extremely difficult to execute. As an example, I had a conversation with a potential distributor who told me that he also built an amplifier without global feedback but it physically exploded in a few days. My answer was, "Now you understand why it took 16 years to make this work correctly."
 
Q: Moving to the preamp, when did you begin the design?
A: (Serge) Four years ago. Hervé has thousands of design ideas in his head. One of my jobs as partner is to keep focus. Originally, Hervé probably conceived of the design at the same time as the amplifier.
 
Q: Describe the journey to get to the release of the new preamp.
A: I originally wanted to share my design with the most people before it became a commercial product. I wanted to share the circuit with the DIY community, share it with other enthusiasts because I knew that the machine would be very expensive to make. There is a lot inside. The preamp is even more expensive because there are more than 1,000 components in the design – six hundred components for the motherboard and four hundred components for the phono preamp. Again, it is difficult to make this simple design work well. You need the correct power supply, the expensive 'mystery light' components for switching and volume, the DC offset has to be controlled and many other things. Although the signal path is simple, there are a lot of components to make it work properly.
 
Q: As to the design, why the unique gold and red case color?
A: It was a big controversy. All other brands are either gray or black. People said, "I can't put your amp in my system; it does not match." Now with the preamp, we have two matching components. Maybe when we launch a source component, like a CD player or integrated amp, the entire system will match. I wanted something different and fun. The 'eyes' and 'power nose' are on the amp. The preamp has a 'pleasure control' for volume and 'enjoyment source' for input selection. I believe that sometimes the audiophile life is taken too seriously. People listen for bass, midrange, highs, soundstage etc. but I just listen for music. I wanted to make my machines more fun, pleasing and human.
 
Q: You must listen for some specific sound qualities.
A: It is all about the music. It doesn't matter if the recording is good or bad; I don't care. If you have a good recording, it is better, but I prefer to listen to the music.
(Serge's answer to continue) Emotion! At the London Show, we spent a half day setting up the room. Our first listening session had no emotion. Maybe it was our exhaustion or not being used to the new room. However, the next day, goose bumps. We had three demo records to play. Every time we played the same tracks, I had the same emotional experience - even three days later. People would come back again and again. You watch them sit and unconsciously move to the music. They are touched by the emotion.
 
Q: I am fascinated by the mysterious volume control light system.
A: Mark Levinson, for example, uses a chip with trim resistors in a ladder configuration and they switch them with FET transistors. The problem with FETs is that you have a silicon junction and the signal is altered by the switch. You can use relays but the contact remains the problem. There is an electrical potential difference between two contacts so here we use a similar resistor ladder but we switch using our light system instead of relays. The entire process is digitally controlled with sophisticated software. The processor is always idle except when you touch a button so there is no active clock in the machine to disturb the sound.
 
Q: Keeping with simplicity, you did need a remote?
A: Yes, but only volume and mute since there are no digital readouts on the preamp. When the remote is activated, the LEDs change from red to green to show that the preamp is receiving the remote signal.
Q: No input changing by remote?
A:: No, generally when you change the source you have to get up and change the CD or record. Keeping with the original design, I did not want a remote but it was conveyed to me that this was necessary by our US importer.
 
Q: Let's take a quick tour of the preamp.
A: The entire component is dual mono beginning to end. The first board is the phono preamp, with over 200 SMD (Surface Mounted Devices) per channel but again, there are only eight junctions in the signal path from input to output. The balanced input card is a bit different because we put a transformer on the card. All inputs are selected between RCA or our BNC 50-ohm proprietary links. There are three BNC outputs for amplification (to allow tri-amping) and each output has its own dedicated buffer. There are no jumpers. We use tiny pads which are soldered or not soldered to make the switch for phono impedance and gain.
 
Q: Can the phono preamp settings be changed by the end user?
A: We can do it at the factory but if the end user can use a soldering iron, he can change it himself.
Q: What about phono gain?
A: The maximum phono gain is 66dB plus an additional 13dB in the line, so you have a lot of gain available.
Q: Resistive phono loading?
A: We have four resistors that combine for many loads from 100 ohms to 47k. There is no capacitive loading because the new MM cartridges do not require it. We do have an optional capacitor to kill RF interference.
Q: Again, is the resistive loading user changeable?
A: The end user can do it but it is better that we set it up. The standard configuration for MC is 60dB of gain and a 330 ohm load - a good standard.
 
Q: Speaking of cartridges, what is in your personal system?
A: We have a special EMT cartridge modified by Van den Hul. It is like a Colibri, just amazing but less hard on the sibilants and very sweet. He made 23 modifications, changing the diamond, cantilever wire, capacitors and more. It sounds fantastic.
 
Q: Let's discuss the batteries. A few designers have tried them with success but it is certainly not in the mainstream. The trend in high end preamp seems to be separate components with massive power supplies, high filtration and regulation with tons of current capabilities. Why battery power?
A: The problem with external power supplies is that you still have the umbilical connecting wire so the impedance in the preamp is higher. You need to add regulation inside it to lower the impedance of the power supply. No matter how much you filter the power supply, you still have residual noise. With batteries, you don't have any noise because there is no magnetic field.
 
Q: I am not an engineer but I have heard that batteries while low in noise, suffer from their own impedance problems.
A: That is true when you use a battery to power the circuit directly. Manufacturers sometimes think, "Okay, we use batteries so we don't need to regulate because there is no hum or alternating current." But it doesn't work like this. We have a twelve volt battery regulated at ten volts. The regulators lower the voltage because when a battery is full it outputs thirteen volts and declines as it discharges to about eleven volts. This is not good for the circuit if the voltage is not constant. Also the impedance of the battery is lowered so everything is happy.
 
Q: Describe the operation under battery power.
A: Like the amp, once it is broken in, you do not have to leave the preamp on or warm it up for best sound. It needs only fifteen minutes of warm up. Therefore, we recommend that you turn the preamp off when not used. When it is off, it is always charging the batteries.
Q: What is the playing time with batteries?
A: The playing time with batteries is 15 hours. After fifteen hours, the preamp will automatically switch from battery to AC and simultaneously charge the batteries. There is a small but noticeable difference in sound while it is charging. This is another reason not to leave the preamp on all of the time. When you are ready to listen, the batteries could be in a charging cycle.
Q: What about battery life?
A: The batteries, of course, are the highest quality Japanese Yuasa or American Genesis batteries. If you leave the machine on continuously, battery life would be about three years due to the constant cycling. If you turn the machine off after listening, the batteries will not be completely drained so the charge can start with maybe one half power reserve and you can expect perhaps four to six years of use.
 
Q: Does the preamp have to go back to Switzerland for battery replacement?
A: No, local service repairs in each country can change the batteries.
 
Q: What type of battery is used?
A: Twelve volt, five-amp lead acid because these are the only batteries which do not have a memory effect. They can be charged at any time at any level of discharge.
 
Q: What is your recommendation for after-market power cords?
A:: I tried some but I am not a tweaky guy. Tweaks will change the sound but I am not sure that they will improve the sound - different maybe but not necessarily better. If the incoming power is good, the cabling will have a lesser effect. You can get better results from just cleaning your contacts.
 
Q: Tell me about the Zeel links. Why create a non-standard connection?
A: Our system is single-ended. I really don't believe in balanced. With balanced, you either have to use transformers or twice the electronics. The preamp has balanced inputs and outputs with transformers. I prefer them because they are immune to hum. They are there to be compatible with the professional standard but for me, single-ended is much simpler. In addition to the single-ended and balanced sockets, we have the fifty-ohm input and output.
 
Q: If you were happy with single-ended connections, why invent another type?
A: There are too many differences among audio interconnects. These differences are not marginal. I examined the problem and wondered if it is really the cable itself or only a problem of mismatch. I conducted an experiment at the Geneva Engineering School and it showed that if you are not matched, you will have some signal reflections. Although these 'echoes' occur above the audible threshold, I found that when you are matched, the sound is much cleaner because you do not have these reflections. It is like the integrity of phase or speed. You do not have any timing errors.
 
Q: What is the maximum length of these Zeel links?
A: One kilometer! Yes, one thousand meters of cable! There is no loss of highs or transients because the signal is matched. When you have a reflection in the cable, the signal bounces back and forth. Square waves become rounder not because of capacitance or inductance but because the interaction of the reflected signal causes the square wave to round over the edge because each return step is added together not in phase. The sum of these reflected steps is a rounding edge of the square wave. When you are matched, there are no reflections and it works.
Q: Can you hear the difference on a short run of, let's say, seven meters?
A: I can tell the difference with a one meter run. I compared my old Kimber Reference Cable, which I loved, and while less than longer runs, it is still clearly audible - less glare.
 
Q: Do you supply the 50-ohm cable?
A: While any fifty-ohm cable will work, we use specially made Swiss cable - small, thin, very good isolation, silver-coated, and they sound slightly better than standard cables. Since they are very thin, they can be run under carpet or near the walls.
 
Q:: What does the future hold for darTZeel?
A: In the very high end, we will make a monoblock amplifier and possibly a source component like a CD player, but coming back to our 'sharing the pleasure' philosophy, we will then make an entry-level product such as an integrated amplifier. This is a real challenge - where to cut costs while keeping the darTZeel sound. Our goal will be to make a product available to 95% of the community. Sometime in the future, we might make a 'cost is no object' piece, maybe only ten pieces just for the fun of it. The success of darTZeel up to this point has been accomplished without any advertising. We go to shows and let people hear the amp. The best advertisement is to let people listen to the products.
........
.Hervé Delétraz Interview with Mike Malinowksi
What did all this mean when it comes to reproducing exquisitely recorded music? I became mesmerised.........
Paul Millar
REVIEW SUMMARY: Fed high quality recordings, the LHC-208 proved capable of tremendous fine detail retrieval and bewitching image dimensionality. There is an impressive naturalness in the way it presents images of musicians in space and the soundstage always appears deep and wide.

The sound is charming and inviting in its overall balance – with thrilling dynamics when the music commands – and as others have observed with darTZeel’s costlier amplifiers, its tone is vibrant without ever appearing ‘coloured’. It seemingly never fails to draw you in, making you want to relax and listen to the music rather than analyse its constituent elements.

Using a squeaky-clean Melco N1A server [HFN Aug ’15] for playing CD rips and hi-res downloads, we listened to the LHC-208 driving a pair of Focal’s lovely Sopra No 2 floorstanders in the editor’s media room. Bass was extended and rich, perhaps not as tightly controlled as with some muscle amps, yet nicely integrated and always self-assured.

Midrange and HF was what many might describe as ‘valve-like’, so what you hear as a result is almost always easy on the ear unless bashing out Metallica at full throttle!

I don’t want to paint an impression that the new ‘baby’ darTZeel sounds soft and cuddly. Interestingly, The Fab Four’s ‘And I Love Her’ [2009 remaster at 44.kHz/24-bit sounded eerily stark and calmly uncluttered, allowing forensic observation of the performers and the subtle inflections in their phrasing that often go unnoticed. Certainly the LHC-208’s strong suits appear to be its convincing speed and attack through mid to-high-frequencies – making acoustic guitars wholly believable – together with seemingly effortless transparency. So while its midrange wasn’t warm and ‘tubey’, neither was it ever wiry or artificial sounding, Indeed, in that regard it almost could be described as sounding like a tube amplifier!

What did all this mean when it comes to reproducing exquisitely recorded music? I became mesmerised listening to guitarist  Antonio Forcione’s and singer Sabina Sciubba’s version of Stevie Wonder’s ‘Visions’ from their album Meet Me In London ....

Offering fine sound quality and enough inputs to satisfy most system set-ups, darTZeel’s LHC-208 is a highly desirable integrated amp/network player/DAC solution for audiophiles determined to stand out from the crowd. It might not drip functionality, but what it does it executes exceedingly well, with promises of many software updates in the pipeline for those privileged to own it.

EXTENDED REVIEW: You’ve got to hand it to darTZeel: the boutique Swiss brand barely registered in the consciousness of audiophiles a little over a decade ago, yet it now represents one of the most desirable marques in high-end audio. An analogue replay stalwart to the core, the fi rm hasn’t had a single digital product in its portfolio… until now 

Priced at £13,500 (NZ$19995 incl GST) the brand new LHC-208 integrated stereo amplifier, rated at 175W/8ohm and designed to provide a flavour of the company’s headier pre/power offerings at a more affordable price than its ‘close to heaven’ CTH-8550 integrated amp [HFN Jul ’09], features analogue and digital inputs – with not only a built-in DAC but also a network music player on board.

BREWED SLOWLY

Refer back to our interview with company founder and maverick designer Hervé Delétraz [HFN Mar ’09] and you’ll see that nothing happens overnight at darTZeel. Hervé spent almost 20 years developing the first NHB-108 power amplifer. No surprise, then, that this new LHC-208 has been several years in the making too – and it continues to be ‘work in progress’ with various software updates planned for the near future.

In Hervé’s words: ‘When this project began we didn’t have any digital features in mind whatsoever. My intention was to produce a more affordable darTZeel integrated amplifier with a motorised potentiometer, a simple remote handset and perhaps three line inputs.’

Step by step, the idea of including a digital input in a darTZeel machine began to germinate but Hervé was determined to fashion something uniquely darTZeel in design. He employed very simple digital circuits, with no unnecessary oversampling, while, crucially, source formats are handled natively, with no conversion from DSD to PCM or vice versa.

For its USB input the LHC-208 employs the latest XMOS interface that offers compatibility with 384kHz/24-bit and DSD128 sources. Furthermore, removing the amplifier’s bonnet reveals that all circuits are on bespoke darTZeel PCBs, its streaming board developed in conjunction with one of the company’s longstanding technology partners.

While, as we’ve said, there are updates planned for later this year and next, streaming functionality is currently limited to playing music fi les stored on a server – a computer or NAS – with no access to internet radio or web streaming services such as Spotify or Tidal. Also, as the DAC is TI’s DSD1796, incoming 384/352.8kHz PCM fi les are necessarily down sampled to 192/176.4kHz, respectively.

Naturally it comes dressed in darTZeel’s familiar gold and burgundy red livery, the amplifier’s front panel dominated by a TFT touch screen. Swiping a finger across it brings the unit out of standby.

The company’s whimsical eccentricity remains evident not only in its calling the product a ‘danalogue’ amplifier but also the on-screen messages saying ‘Entering/Leaving little heaven corner’ when you turn it on/off. This is the fi rm that labels its preamp’s volume knob ‘Pleasure Control’…

DEDICATED HEADPHONE AMP

The touch screen offers good legibility and access to all on-board functionality, the plus and minus signs on the left and right portions of the screen to govern volume up/down proving satisfactorily responsive to deft finger taps. The display also shows the sampling frequency of incoming data as well as the current volume setting, but it doesn’t show album artwork. I did mention that it was work in progress…

What appear at first glance to be small rotary controls on the fascia are actually styling details disguising the unit’s IR receiver and front panel sockets in their centres. On the left is a 6.35mm headphone socket, on the right a minisocket handy for temporary hook-up of visiting portables, with the IR receiver eye centre most of the three. The LHC-208 features a dedicated headphone amplifier with headphone volume controlled independently of the main output; the speaker output is automatically disabled once cans are connected.

At the rear there are three line-level RCA inputs, a 50ohm BNC ‘Zeel’ input (ready for any future darTZeel source components with a matching ‘darT’ output), an Ethernet port, USB-B connector for pushing data directly into the on-board DAC from a computer, and four S/PDIF inputs (two optical, two coaxial). A further USB-A connector is for fi rmware updates and serial-code activation via memory stick, while a single set of Cardas-style ‘clamps’ provide speaker cable connection.

Determined to maintain the sonic signature of its more expensive amplifiers darTZeel has employed the same analogue audio circuits featured in the dual-mono CTH-8550, save that the LHC-208 has all left and right preamp and power amp stages on the same printed circuit board, and both channels share a common power supply and capacitor bank.

And the LHC-208 employs a new custom designed heatpipe cooling system, made for darTZeel by Swiss company Arctic (which specialises in cooling devices for hot-rodded computers in the IT industry). You don’t get a chunky handset hewn from an aluminium billet with the LHC-208, instead a lightweight plastic controller is supplied (A serious remote is in the winds). This helps keep manufacturing costs down, but was also a deliberate and eminently sensible decision since most owners will surely control playback of their music libraries via a tablet.

A unique darTZeel app for iOS, Android and Windows 10 is in the works which will make the RCU redundant anyway, since it promises to duplicate the functionality of the amplifier’s front panel touch screen and provide access to all menu and control settings. The app is scheduled for release next year. In the meantime, when using a tablet as a control point for browsing a music library darTZeel recommends using BubbleUPnP for Android devices and PlugPlayer (or similar) for iPads.

SIMPLY DRAWS YOU IN

Fed high quality recordings, the LHC-208 proved capable of tremendous fine detail retrieval and bewitching image dimensionality. There is an impressive naturalness in the way it presents images of musicians in space and the soundstage always appears deep and wide.

The sound is charming and inviting in its overall balance – with thrilling dynamics when the music commands – and as others have observed with darTZeel’s costlier amplifiers, its tone is vibrant without ever appearing ‘coloured’. It seemingly never fails to draw you in, making you want to relax and listen to the music rather than analyse its constituent elements.

Using a squeaky-clean Melco N1A server [HFN Aug ’15] for playing CD rips and hi-res downloads, we listened to the LHC-208 driving a pair of Focal’s lovely Sopra No 2 floorstanders in the editor’s media room. Bass was extended and rich, perhaps not as tightly controlled as with some muscle amps, yet nicely integrated and always self-assured.

Midrange and HF was what many might describe as ‘valve-like’, so what you hear as a result is almost always easy on the ear unless bashing out Metallica at full throttle!

I don’t want to paint an impression that the new ‘baby’ darTZeel sounds soft and cuddly. Interestingly, The Fab Four’s ‘And I Love Her’ [2009 remaster at 44.kHz/24-bit sounded eerily stark and calmly uncluttered, allowing forensic observation of the performers and the subtle inflections in their phrasing that often go unnoticed. Certainly the LHC-208’s strong suits appear to be its convincing speed and attack through mid to-high-frequencies – making acoustic guitars wholly believable – together with seemingly effortless transparency. So while its midrange wasn’t warm and ‘tubey’, neither was it ever wiry or artificial sounding, Indeed, in that regard it almost could be described as sounding like a tube amplifier!

ENHANCEMENT TO COME

But it was the darTZeel’s innate ‘fluidity’ that became increasingly obvious the longer I listened, its ability to make sense of the musical message whatever the challenge. Playing the heavily processed Papercutz remix of Lucrecia Dalt’s ‘Escopalina’, the bonus tracks from the Barcelona-based singer/composer’s Commotus album of 2012 [Human Ear Music HEM019], proved a case in point, as the amplifier exposed the track’s many layers of electronic compositional collage while magically obviating the recording’s intrinsic shrillness.

Again, the bass wasn’t tightly contoured or as controlled as it might be, possessing a slightly thickening ‘bloom’. Nevertheless this is something that many might judge advantageous when spending time listening to ‘ordinary’ recordings ie, most of the time!

What did all this mean when it comes to reproducing exquisitely recorded music? I became mesmerised listening to guitarist  Antonio Forcione’s and singer Sabina Sciubba’s version of Stevie Wonder’s ‘Visions’ from their album Meet Me In London [Naim Label, 192kHz/24-bit download].

The transient attacks of Forcione’s nylon guitar strings were appropriately fast and clean (but not ‘hyped’ to make them sound more like steel strings), his acoustic instrument appearing carved brilliantly in three-dimensional space. Sciubba’s voice was also rendered gorgeously, if slightly reduced in the warmth to which I’m more usually accustomed. Still, I couldn’t fail to conclude it was a complete and delightfully composed sonic picture.

Despite the LHC-208 being fresh out of the starting blocks and waiting for its streaming functionality to be enhanced via future updates, its charming sound quality is very much all of a piece. We’re told the first free update will be an improved menu layout to make the screen more readable from a listening seat – with more status information visible simultaneously, despite the use of larger fonts. Displaying album cover art as well should follow soon thereafter. 

…….. Paul Miller

it was the darTZeel’s innate ‘fluidity’ that became increasingly obvious the longer I listened, its ability to make sense of the musical message whatever the challenge
John Bamford

REVIEW SUMMARY: But it was the darTZeel’s innate ‘fluidity’ that became increasingly obvious the longer I listened, its ability to make sense of the musical message whatever the challenge. Playing the heavily processed Papercutz remix of Lucrecia Dalt’s ‘Escopalina’, the bonus tracks from the Barcelona-based singer/ composer’s Commotus album of 2012 [Human Ear Music HEM019], proved a case in point, as the amplifier exposed the track’s many layers of electronic compositional collage while magically obviating the recording’s intrinsic shrillness. What did all this mean when it comes to reproducing exquisitely recorded music? I became mesmerised listening to guitarist Antonio Forcione’s and singer Sabina Sciubba’s version of Stevie Wonder’s ‘Visions’ from their album Meet Me In London [Naim Label, 192kHz/ 24-bit download]. The transient attacks of Forcione’s nylon guitar strings were appropriately fast and clean (but not ‘hyped’ to make them sound more like steel strings), his acoustic instrument appearing carved brilliantly in three-dimensional space. Sciubba’s voice was also rendered gorgeously, if slightly reduced in the warmth to which I’m more usually accustomed. Still, I couldn’t fail to conclude it was a complete and delightfully composed sonic picture. 

EXTENDED REVIEW: You’ve got to hand it to darTZeel: the boutique Swiss brand barely registered in the consciousness of audiophiles a little over a decade ago, yet it now represents one of the most desirable marques in high-end audio. An analogue replay stalwart to the core, the fi rm hasn’t had a single digital product in its portfolio… until now

Priced at £13,500 the brand new LHC- 208 integrated stereo amplifier, rated at 175W/8ohm and designed to provide a flavour of the company’s headier pre/power offerings at a more affordable price than its ‘close to heaven’ CTH-8550 integrated amp [HFN Jul ’09], features analogue and digital inputs – with not only a built-in DAC but also a network music player on board. 

BREWED SLOWLY

Refer back to our interview with company founder and maverick designer Hervé Delétraz [HFN Mar ’09] and you’ll see that nothing happens overnight at darTZeel. Hervé spent almost 20 years developing the first NHB-108 power amplifier. No surprise, then, that this new LHC-208 has been several years in the making too – and it continues to be ‘work in progress’ with various software updates planned for the near future. 

In Hervé’s words: ‘When this project began we didn’t have any digital features in mind whatsoever. My intention was to produce a more affordable darTZeel integrated amplifier with a motorised potentiometer, a simple remote handset and perhaps three line inputs.’ Step by step, the idea of including a digital input in a darTZeel machine began to germinate but Hervé was determined to fashion something uniquely darTZeel in design. He employed very simple digital circuits, with no unnecessary oversampling, while, crucially, source formats are handled natively, with no conversion from DSD to PCM or vice versa. 

For its USB input the LHC-208 employs the latest XMOS interface that offers compatibility with 384kHz/24-bit and DSD128 sources. Furthermore, removing the amplifier’s bonnet reveals that all circuits are on bespoke darTZeel PCBs, its streaming board developed in conjunction with one of the company’s longstanding technology partners. 

While, as we’ve said, there are updates planned for later this year and next, streaming functionality is currently limited to playing music files stored on a server – a computer or NAS – with no access to internet radio or web streaming services such as Spotify or Tidal. Also, as the DAC is TI’s DSD1796, incoming 384/352.8kHz PCM files are necessarily down sampled to 192/176.4kHz, respectively. Naturally it comes dressed in darTZeel’s familiar gold and burgundy red livery, the amplifier’s front panel dominated by a TFT touch screen. Swiping a fi nger across it brings the unit out of standby. The company’s whimsical eccentricity remains evident not only in its calling the product a ‘danalogue’ amplifi r but also the on-screen messages saying ‘Entering/ Leaving little heaven corner’ when you turn it on/off. This is the fi rm that labels its preamp’s volume knob ‘Pleasure Control’…

DEDICATED HEADPHONE AMP

The touch screen offers good legibility and access to all on-board functionality, the plus and minus signs on the left and right portions of the screen to govern volume up/down proving satisfactorily responsive to deft finger taps. The display also shows the sampling frequency of incoming data as well as the current volume setting, but it doesn’t show album artwork. I did mention that it was work in progress… 

What appear at first glance to be small rotary controls on the fascia are actually styling details disguising the unit’s IR receiver and front panel sockets in their centres. On the left is a 6.35mm headphone socket, on the right a mini socket handy for temporary hook-up of visiting portables, with the IR receiver eye centre most of the three. The LHC-208 features a dedicated headphone amplifier with headphone volume controlled independently of the main output; the speaker output is automatically disabled once cans are connected. 

At the rear there are three line-level RCA inputs, a 50ohm BNC ‘Zeel’ input (ready for any future darTZeel source components with a matching ‘darT’ output), an Ethernet port, USB-B connector for pushing data directly into the on-board DAC from a computer, and four S/PDIF inputs (two optical, two coaxial). A further USB-A connector is for firmware updates and serial-code activation via memory stick, while a single set of Cardas-style ‘clamps’ provide speaker cable connection. 

Determined to maintain the sonic signature of its more expensive amplifiers,  darTZeel has employed the same analogue audio circuits featured in the dual-mono CTH-8550, save that the LHC-208 has all left and right preamp and power amp stages on the same printed circuit board, and both channels share a common power supply and capacitor bank. 

And the LHC-208 employs a new custom designed heatpipe cooling system, made for darTZeel by Swiss company Arctic (which specialises in cooling devices for hot-rodded computers in the IT industry). You don’t get a chunky handset hewn from an aluminium billet with the LHC-208, instead a lightweight plastic controller is supplied [pictured on p35]. This helps keep manufacturing costs down, but was also a deliberate and eminently sensible decision since most owners will surely control playback of their music libraries via a tablet. 

A unique darTZeel app for iOS, Android and Windows 10 is in the works which will make the RCU redundant anyway, since it promises to duplicate the functionality of the amplifier’s front panel touch screen and provide access to all menu and control settings. The app is scheduled for release next year. In the meantime, when using a tablet as a control point for browsing a music library darTZeel recommends using BubbleUPnP for Android devices and PlugPlayer (or similar) for iPads. 

SIMPLY DRAWS YOU IN 

Fed high quality recordings, the LHC- 208 proved capable of tremendous fi ne detail retrieval and bewitching image dimensionality. There is an impressive naturalness in the way it presents images of musicians in space and the soundstage always appears deep and wide. 

The sound is charming and inviting in its overall balance – with thrilling dynamics when the music commands – and as others have observed with darTZeel’s costlier amplifiers, its tone is vibrant without ever appearing ‘coloured’. It seemingly never fails to draw you in, making you want to relax and listen to the music rather than analyse its constituent elements. 

Using a squeaky-clean Melco N1A server [HFN Aug ’15] for playing CD rips and hi-res downloads, we listened to the LHC-208 driving a pair of Focal’s lovely Sopra No 2 floorstanders [also HFN Aug ’15] in the editor’s media room. Bass was extended and rich, perhaps not as tightly controlled as with some muscle amps, yet nicely integrated and always self-assured. Midrange and HF was what many might describe as ‘valve-like’, so what you hear as a result is almost always easy on the ear – unless bashing out Metallica at full throttle! 

I don’t want to paint an impression that the new ‘baby’ darTZeel sounds soft and cuddly. Interestingly, The Fab Four’s ‘And I Love Her’ [2009 remaster at 44.kHz/24-bit] sounded eerily stark and calmly uncluttered, allowing forensic observation of the performers and the subtle inflections in their phrasing that often go unnoticed. Certainly the LHC-208’s strong suits appear to be its convincing speed and attack through mid to-high-frequencies – making acoustic guitars wholly believable – together with seemingly effortless transparency. So while its midrange wasn’t warm and ‘tubey’, neither was it ever wiry or artificial sounding, Indeed, in that regard it almost could be described as sounding like a tube amplifier!

ENHANCEMENT TO COME 

But it was the darTZeel’s innate ‘fluidity’ that became increasingly obvious the longer I listened, its ability to make sense of the musical message whatever the challenge. Playing the heavily processed Papercutz remix of Lucrecia Dalt’s ‘Escopalina’, the bonus tracks from the Barcelona-based singer/ composer’s Commotus album of 2012 [Human Ear Music HEM019], proved a case in point, as the amplifier exposed the track’s many layers of electronic compositional collage while magically obviating the recording’s intrinsic shrillness. 

What did all this mean when it comes to reproducing exquisitely recorded music? I became mesmerised listening to guitarist Antonio Forcione’s and singer Sabina Sciubba’s version of Stevie Wonder’s ‘Visions’ from their album Meet Me In London [Naim Label, 192kHz/ 24-bit download]. 

The transient attacks of Forcione’s nylon guitar strings were appropriately fast and clean (but not ‘hyped’ to make them sound more like steel strings), his acoustic instrument appearing carved brilliantly in three-dimensional space. Sciubba’s voice was also rendered gorgeously, if slightly reduced in the warmth to which I’m more usually accustomed. Still, I couldn’t fail to conclude it was a complete and delightfully composed sonic picture. 

Despite the LHC-208 being fresh out of the starting blocks and waiting for its streaming functionality to be enhanced via future updates, its charming sound quality is very much all of a piece. We’re told the first free update will be an improved menu layout to make the screen more readable from a listening seat – with more status information visible simultaneously, despite the use of larger fonts. Displaying album cover art as well should follow soon thereafter. 
........  John Bamford

HIFI NEWS VERDICT: a very HIGH for an INTEGRATED AMP - 84%
"Offering fine sound quality and enough inputs to satisfy most system set-ups, darTZeel’s LHC-208 is a highly desirable integrated amp/network player/ DAC solution for audiophiles determined to stand out from the crowd. It might not drip functionality, but what it does it executes exceedingly well, with promises of many software updates in the pipeline for those privileged to own it." 

HIFI NEWS COMMENT - DARTZELL GOES DIGITAL:
"It’s a sign of the times that even bastions of the analogue replay world are embracing digital networking as it becomes increasingly ubiquitous in modern homes. Your mileage might vary (mine certainly does), nevertheless darTZeel’s Hervé Delétraz is correct in observing that many audiophiles consider analogue master tape, followed by vinyl LP, to be superior to any digital source. Says Hervé: ‘It’s not that we didn’t want to enter the digital world before now, it is just that it’s taken time for us to turn our ideas into the real thing.’ ‘Whatever the digital source, some fatigue is perceived compared to analogue which fl ows like a quiet river without turbulence. Digital is a metronomic way of playing music, as if a robot was imposing the beat instead of musicians. In keeping our digital section “simple”, paying due care and attention to internal layout and avoiding any switching power supplies, I’ve found for the fi rst time I can now listen to digital for more than 30 minutes before switching back to LPs. I’ve found that digital can be “liquid” too.’ By heck, Hervé... D’ya mean to say that in today’s high-end audio world the future sure ain’t what it used to be"?

Videos

Introduction to DarTZeel manufacture