A new approach to preamplification

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

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.