General Asylum: REVIEW: Audio Note DAC 3.1 Signature DAC Processors by George Sallit

AudioNote makes unconventional hifi. And this DAC is about as unconventional as it gets.

Why ?

In order to reproduce the full range of music (0-20kHz) standard CD samples at 44kHz. According to the Nyquist theory this should reproduce all music between 0 and 22kHz. So far so good, but in order to filter out the supersonic signals that could interfere with the music you want the sampling frequency (44 KHz) and the downwards reflection of the 0-20KHz music (44KHz to 24 kHz) to be removed. This requires a powerful (brick wall) filter that leaves the 0-20 kHz signal untouched but removes the noise above 24 kHz. Such filters are easy to build, theoretically, and have been used. Unfortunately they can cause problems to the music. So enter oversampling. If you oversample by 2x, the sampling frequency goes to 88 kHz and the sort of filter you use can be gentler and cause less problems to the music. Most CDs nowadays oversample at 8x, so all in the garden is rosy.

Not so for Audionote. They hate it. So over the last 8-10 years they have been working on a 1x sampling rate and gentle filters. But what about all that unwanted rubbish ? Not as great a problem as you may think. Despite this the DAC measures badly (based on magazine reviews). But how does it sound ?

Well after leaving it on for a few days it was down to testing.

First CD was Simon and Garfunkel's Bridger over Troubled Waters. I always liked this music but only recently bought the vinyl album. On track 1 of the vinyl the realism in the voices was such that you felt you were at a performance and did not want to talk etc. This CD+DAC is the first time I have got anywhere near this level of performance (both senses of the words). On Cecilia, I have heard really tight precussion sounds, deep bass, etc but this was a real performance with a slightly contrived party feel. And so it was with the rest of the album a real performance and a feel for what S&G wanted. All the hifi bits were there such as no digital screech, deep bass, three D soundstage but added to it was the nuances of the performance.

On more up front music such as Led Zepplin, Pink Floyd, REM, Jon Bon Jovi the same effect came through in varying degrees. Here the timing and power of the music is very important and bland is not a word that can be used for this DAC. On the better recordings the cymbals did not sound like spray cans or steam escaping, they sounded like tuned musical instruments (which is what they are). And yes it is possible to have subtle rock music.

On classical music a much better atmosphere of the recordings emerged with a really good understanding of the hall before any notes were played. Up go the faders and it's a really big/small hall. Some recordings were excellent in this respect others unfortunately turned out very flat (close miked). In choral and operas the character and power of the singers came through really well. Some did sound like they were going through the motions others put their heart and soul into it.
Also the huge power of an ochestra 'going for it' was not compressed but came pouring through.

For me, CD has always had a digital screech (reduced recently), flat dynamics and a colourless tone. This DAC cured these problems and added a real performance feel to the music.

This combination is probably the best I have heard CD and tempts me to compare it to the Linn CD12 and Naim CDS2.

Against SACD and vinyl it was slightly colourless and and a little too sharp but was not as unbearable as 'normal' CD.

I will listen to more and more CDs and get abetter feel for what it does but so far this DAC shows there is more in 16/44.1 and gives a choice for new music. My choice would be vinyl/SACD then CD and I do not now feel short-changed.

REVIEW: Audio Note DAC 3.1 Signature DAC Processors Review by George Sallit at Audio Asylum