sound by singer high end audio video tel: 212.924.8600 - fax: 212.366.6351
242 West 27th St, 2nd Floor
New York, NY 10001




          darTZeel was born out of Herve Deletraz’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. Their  NHB series of separates have been lauded the world over for their exquisite musicality.

darTZeel designs audio machinesthat can convey the emotions at the heart of a musical performance. At darTZeel, the only question  they want to answer is: Does it make the music feel real? Their passion drove  them  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  them  to spend 16 years on one design, “measured performance” alone was not the only goal.

Dartzeel  products, before anything, are designed and realized from a purely humanistic point of view. For DT music is not only a means for communicating and listening. Far more than this, for  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 darTZeel  designs its products.


darTZeel NHB-108 model one Power Amplifier

What do the two most musical solid state amplifiers have in common?        

1)They are both made in Switzerland

2) They both output about 100 watts per channel
3)They are both made well,  like a swiss watch!
4) They both reproduce music with the verisimilitude heretofore only associated with the finest tube amps
              The thing is: 
One costs $ 50,000.00 .The other only $32000.00.
The darTZeel NHB-108 model one
Is that other amp ;an amp which more than anything I have ever heard captures the emotion and soul of  live music.
The 108 can drive almost anything as loud as you would ever need it to be with a beauty and majesty that makes me shudder with anticipation when I think about it.It doesn’t come better than this !
The essence of darTZeel NHB-108  was captured by Mike Malinowski in his review when he wrote:
Hervé started this journey with the premise of designing not just another amp but one that was truly better. Did he succeed? Spectacularly so. The 108 is a dazzling tube-sounding amp cavorting around in the guise of transistors. It has the best traits of tubes and solid state - magic midrange with spectacular soundstaging. It is harmonically rich and satisfying. The sound touched my soul. It infused air around the instruments and made music come alive with a deep and powerful low end. It is truly involving, with a gorgeous liquidity that conveys the emotion of the music. Having graduated to tubes, I thought I'd never look back. The darTZeel has made me rethink that premise. It's a stunning piece of equipment that has raised my system to a new level of performance. Highly recommended.” July 2005
Technical specifications

darTZeel NHB-108 model one

Nominal output power:

100 watts RMS @ 8 (Hi) and 2 (Lo)Ohms .
160 watts RMS @ 4 (Hi) and 1 (Lo) Ohms.


26 dB @ 8 Ohms.

Input impedances:

Version A:

Version B:

RCA: > 30 kOhms, 5 Hz to 200 kHz.
BNC: 50 ±1 Ohms, 1 Hz to 1 MHz.
XLR: > 100 kOhms bet. Pin 1 and 2 (hot leg and ground).
XLR: > 13 kOhms bet. Pin 1 and 3 (cold leg and ground).
33 kOhms bet. Pin 1 and 2.
33 kOhms bet. Pin 1 and 3.

Output impedance:

< 0.33 Ohms, from 20 Hz to 20 kHz (measured @ 8 Ohms).

Frequency response:

1 Hz to 1 MHz, +0, -6 dB (depends on measurement method).
10 Hz to 100 kHz, +0, -0.5 dB (depends on measurement method).
20 Hz to 50 kHz, ±0.5 dB (Version B, XLR inputs).

Rise time:

< 0.8 µs.

Slew rate:

88 V/µs, peak-peak.

DC voltage output drift:

Version A : < ± 590 mV max.
Version B : < ± 10 mV max.

Total Harmonic Distortion (THD):

< 1 % from 7 Hz to 77 kHz

Temporal Distortion:

None, at any level and load, as specified above.


< -90 dB from 20Hz to 20kHz.

Signal to noise ratio:

> 105 dB (A) @ nominal power.


150 watts @ idle, up to 1000 watts @ maximum output power.

Size in mm:

440 x 335 x 170 (WxDxH). Total depth including handles: 415 mm.

Net weight:

30 kg.



darTZeel NHB-18NS Preamplifier $36,000.00 ,EXPENsive? not when you hear it!

The darTZeel NHB-18NS is the logical partner to the now legendary NHB-108 model one power amplifier.

In keeping with the very same philosophy, darTZeel uses dedicated circuits reduced to their most basic form. Here again, there is no application of any overall negative feedback. The delicate, small audio signal amplified by the NHB-18NS only passes through 7 silicon junctions from input to output, including the 11 dB full discrete gain stage. For the phono stage, we only add 6 junctions, for a maximum additional boost of 66 dB (77 dB in total).


The advantages of these new circuits, whose designs are patented, are in the same league as the NHB-108 power amplifier: an extreme, pure sound quality never achieved before.

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 means of matched transistors embedded in dedicated integrated circuits. No operational amplifier is used in the entire signal path. As for the NHB-108, all components used in the NHB-18NS preamplifier, with no exception whatsoever, are based on the finest products being produced by leading-edge industry at the present moment.

The first aim of the NHB-18NS is to provide sound reproduction quality Never Heard Before.

Instead of offering a preamplifier based on the same approach as that of our competitors, we at darTZeel chose to think differently, offering for the first time in the world what previously seemed impossible:

- No contact or switches or relay of any kind for the selection of the sources. This revolutionary feature brings a new level of transparency. Instead of routing the signal through a selector box, each input has its own dedicated gain stage, which is enabled or disabled according to the user's choice. The signal is then directly routed to the volume control module.
- A whole new volume control module, which completely avoids the use of any potentiometer, stepped attenuator or analog switch array in the signal path. The sound signal is attenuated in a fully passive way, using special analog optical couplers controlled by a dedicated processor, providing a dynamic range of 96 dB, through 192 discrete steps of 0.5 dB. There is no use of VCAs or any other active component.

Both of these breakthroughs constitute a big step in the right direction: no harm to the signal.


The NHB-18NS is not only new in these aspects. We have also included all the features already implemented in our now famous NHB-108 model one, as follows: 

  • Only small local negative feedback at the inputs.
  • One small, symmetrical, local negative feedback in the voltage gain stages.
  • Open loop, free of all negative feedback for the output stages. 

In addition, the NHB-18NS features advanced possibilities, including the use of multi-amping through darT to Zeel 50-ohm links. Some key features are (per channel): 

  • 1 state-of-the-art dedicated MC phono stage input.
  • 1 XLR full floating input and output.
  • 4 RCA / BNC 50-ohm Zeel inputs.
  • 3 BNC 50-ohm darT outputs, ready for tri-amping, with built-in passive filters which can be user enabled.
  • 1 RCA output.
  • 1 RCA record output (fixed level).
  • All inputs can be Home Theater bypassed (troughout gain of 0 dB).


Power supply

The darTZeel 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 12 hours of listening pleasure before a charge is needed.
A very sophisticated, regulated and dedicated supply for every input and output is provided, ensuring the lowest power supply impedance possible.

A smart automatic function is provided as standard, allowing full battery operation when listening, and charging mode being activated when the preamp is switched off. Hum is gone forever, and there is no need to worry about knowing if batteries need to be charged or not.


A technological marvel, yes but how does it sound?,

Just ask Micahel fremer who said:


"On first hearing, the darTZeel( NHB-18NS ) immediately revealed itself to be stunningly transparent, giving my Wilson Audio MAXX 2 speakers an electrostatic-like top end. Transient speed, resolution, and decay were nothing short of spectacular from day one, and that particular window on reality still retained its grip on my listening experience months later. ... the darTZeel NHB-18NS is among a handful of the finest-sounding pieces of audio gear I have ever heard. Listening through it produced the same serenity I get every time at Avery Fisher Hall, just after the conductor's baton has gone down and the music has begun". June 2007




darTZeel CTH-8550,
 A dual mono "all in one" integrated amplifier, with 9 parameterizable inputs.
The latest darTZeel music machine is the wonderful CTH-8550 a    full featured integrated amplifier.Which combines in one casing
most of the good things musical lovers found in their  flagship NHB series.
 No doubt that this newcomer is a true darTZeel machine.!
The sound proves it ! If you have heard the NHB-108 you have you have heard the CTH-8550 
As Wes Phillips said”    It was about as transparent a window onto recordings as I have ever heard.   ….. I was floored by the CTH-8550's quality, performance, and convenience. It is a dream component.” august 24,2009
 The CHT-8550 features newly designed regulated  power output stages which include on board powe r 
 supplies for a very
compact global layout. This new circuit
brings outstanding transparency, speed,
yet delicacy, giving a maximum listening
With no less than nine inputs in total, the
preamplifier section is dual-mono - one
dedicated circuit per channel - with a
minimal footprint which allows for very               
short signal paths.
The CTH-8550 features newly designed
power output stages which include on
board regulated power supplies for a very 
compact global layout. This new circuit
brings outstanding transparency, speed,
yet delicacy, giving a maximum listening
With no less than nine inputs in total, the
preamplifier section is dual-mono - one
dedicated circuit per channel - with a
minimal footprint which allows for very
short signal paths.

Technical Specifications:

Power output: 220 watts RMS / 8 ohms

350 watts RMS / 4 ohms

Input gain, line: 0 to +22 dB, user defined

Input gain, MM: 24 to 44 dB, user defined

Input gain, MC: 50 to 70 dB, user defined

Input sensitivity: Line 250 mV, Phono 0.5 mV

Frequency response: 10 Hz to 100 kHz, ± 0.5 dB

Total Harmonic Distortion: < 1 % at any frequency

Temporal Distortion: None across full audio range

Crosstalk: < -90 dB from 20 Hz to 20 kHz

Signal to noise ratio: > 100 dB (A), line, @ 2 volts output

> 70 dB (A), phono, @ 2 volts output

Power consumption: Idle 45 watts, maximum 1000 watts.

Standby: less than 5 watts.

Size in mm (WxDxH): 440 x 335 x 170; 415 mm total deep

with handles.

Net weight: 29 kg (approximative)