The DarTZeel NHB-18NS Preamplifier

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.