It is, of course, impeccably well-mannered and locks on very quickly to the incoming digital signal - whereas some high-end DACs can be confusingly slow.

One of the consistent features we've found across a range of upmarket CD players (and since we spent most of our time with the TUBE-DAC partnered to a Drive I, a CD player is effectively what we were testing) is the high degree of polish they bring to the sound, making cheaper players sound rough by comparison. This one is no exception, joining such company as Meridian and dCS in offering sounds that appear to believe their origin.

During the time that high-sampling-rate, high-bit audio has been slowly penetrating the market, CD recording and replay standards have risen making one question what all the high-res fuss is about. In the practical sense of the terms, this is high resolution. And, thanks to an otherwise uneventful Xmas, we had plenty of opportunity to listen at leisure to Accustic Arts' statement on digital replay and our respect remained high across a wide range of music and recordings.

Among the many discs that we were able to audition on the TUBE-DAC was a newly made CD of operatic voice and piano, recorded so recently that the original sound was still fresh in our ears. The recording itself was excellent, that much was obvious from the most casual listen, but the real extent to which the tenor's high notes rang true was much more apparent via the TUBE-DAC than via our resident (modest but capable) CD player.

The human voice is such a familiar sound that any interference with its complex harmonic structure has a disproportionately large subjective effect, making it a good test of audio equipment. In this case, it was clear that both the recording and replay equipment had admirably discharged their function and the sound was less 'digital' than we were used to.

The jitterbug

It's worth mentioning that, we tried playing the same recording from the hard disc of a computer, rather than from the CD in the Drive I. Computers are renowned for being a jittery source, but there was really very little difference between the two. Accustic Arts may not thank us for saying this, but the TUBE-DAC has very good rejection of incoming jitter and is therefore quite unfussy about the source.

Moving a world away to highly processed contemporary pop, the TUBE-DAC is similarly assured, unfazed by the multi-layered nature of studio productions. Rapid, funky synthesiser can prove a tough test for digital sources, but again the result is confident, detailed, almost calm. Which can come as a bit of a shock if you're used to more coloured
audio kit.

If there is anything to criticise, it's a very slight degree of hardness in the highest registers when reproducing instruments with an extended harmonic structure - a violin being perhaps the most critical. In such cases, the 'air' around the instrument is not quite so pure, the decay at the end of notes a touch less well-defined.

Overall, though, this is clearly a very capable DAC indeed, with plenty going for it sonically and, in terms of ownership, it practically exudes class. This experience has certainly made us keen to visit other Accustic Arts products. And who knows what further treats lie in store?