Review: Audio Note DAC 3.1 Balanced DA converter

Category: Digital

I have no commercial link, or connection of any other kind, with Audio Note UK

Last year, dissatisfied with CD reproduction from a Meridian 500 transport and 24-bit DAC front-end, I was casting around for a replacement D to A converter. Up sampling seemed to get a good press (it gets an even better one now) and I initially settled on trying to audition an MSB Link DAC III and the Perpetual Technologies’ P3 combo modified by Wright. It proved too much like hard work due to the distribution arrangements both companies then had in place here in the UK (I do not know whether things have subsequently changed). The Musical Fidelity 3D CD up sampling CD player was then launched and unlike the US-made DACs it was readily available for audition here in Britain.

About this time, trawling the ‘net in an effort to understand how up sampling works, I stumbled over Audio Note’s UK site (www.audionote.co.uk) and the company’s iconoclastic approach to DAC design. You’ll find various postings and reviews here and on AA about how that technology contrasts with the mainstream.

In addition to being different, Audio Note’s approach seems to trigger a spectrum of responses ranging from huge enthusiasm through carefully studied indifference to outright derision. I concluded that a DAC capable of provoking such passion just had to be auditioned.

I borrowed a burned-in Musical Fidelity 3D CD from a local dealer and contacted Audio Note to ask if I could try one of their balanced DACs at the same time. It is perhaps a measure of the degree of confidence that Audio Note owner Peter Qvortrup has in the rightness of his product that, with a balanced version still some months from production, he simply gave me the pre-production prototype to play with: “There it is. Put it in your car and take it away.” There was no faceplate, no lid – just a chassis with all boards and tubes exposed, wrapped up in a big plastic bag.

At home, back-to-back comparison was instructive. Playing first the Musical Fidelity, I heard all the effects that Sam Tellig, Michael Fremer and others in the audio press have raved about. There was indeed more presence and apparent fluidity than the straight over sampled output from my Meridian combo.

Frankly, I was not expecting the prototype Audio Note DAC to excite, but it simply blew the Musical Fidelity away, giving an organic, euphonic, open and astonishingly revealing presentation with pace, rhythm and timing that exposed the up sampled output from the Musical Fidelity box as (comparatively) confused, mechanical and harsh.

As it was, lidless and without a faceplate, the Audio Note had all the visual allure of a trashcan. But sonically it was a revelation. That’s how the Musical Fidelity player came to go back from whence it came, and I ended up buying a single-ended 3.1 Signature DAC (remember, no balanced version then in production) from Audio Note.

I lived with the 3.1 Signature from November last year until last week and it never failed to enliven our enjoyment of an eclectic mix of music from choral through chamber to be-bop and fusion. But I always intended to upgrade to the balanced version when it finally became available.

Last week it did.

Construction
The Audio Note DAC 3.1 Balanced is a black folded metal box approximately 17” wide by 16” deep and 5” high. I guess it only looks large to neophytes used to solid-state electronics. Remove the lid and you discover why it’s so big. Inside are some big bits. There is a hefty valve rectified choke power supply. The digital and analogue stages of the converter live next door, physically separated from the power supply by a metal wall.

All circuit boards are seriously thick and are supported clear of the chassis by multiple pillars. At its heart, the 3.1 Balanced is essentially the same animal as the 3.1 Signature, combining a Crystal CS8414CS receiver chip and an Analogue Devices 1865 18 Bit converter chip with Audio Note’s own transformers and analogue filters, and Philips USA ECC88 valves in the output stage. The key difference comes at the output. Whereas the single-ended DAC uses copper foil/paper in oil signal coupling capacitors, the balanced version uses a honking great pair of Audio Note’s own 600-Ohm transformers. Audio Note says output is around 3 Volts.

The black acrylic back panel hosts a switched IEC mains socket, a pair of silver single-ended outputs, a pair of silver balanced outputs, a 75-Ohm digital input and an AES/EBU input, plus two switches. One selects input, the other inverts phase.

The black acrylic front panel (optional silver anodised aluminium) is understated. Three tiny LEDs in a horizontal row indicate power on, phase invert and de-emphasis (automatic). An Audio Note logo in gold completes the ensemble.

Buyers more used to the showy designs of so many equipment vendors may find Audio Note’s rather austere – let’s face it, low-cost – aesthetic to be rather off-putting. A good DAC has to be housed in a box milled from aircraft grade billet aluminium, right?

Audio Note begs to differ. The box keeps prying fingers away. What matters is what’s inside and how it sounds.

I believe that I am correct in saying that the 3.1 Balanced is the first Audio Note product to be built at the company’s Canadian site run by Mike Kerster, rather than the headquarters in Brighton, UK. Either way, the build exudes quality, thoroughness and attention to detail. High quality components, such as tantalum film resistors and Black Gate capacitors are in evidence (see Web site for full specification). Internal interconnects, some of them silver in Teflon, are neatly routed and secured. Components have been fastidiously aligned, rather than simply slapped on. Joints are neat, bright. This, then, is where the value of the $5950 ticket on the 3.1 Balanced is to be found.

The 3.1 Balanced DAC comes in a box bearing a little white sticker: ‘Assembled in Canada.’ It ought to say: “Hand built in Canada with a great deal of professional pride.’

Sonics
It’s strange how burn-in rates differ. The 3.1 Balanced sounded very, very good, straight out of the packing whereas the single-ended Signature had been reluctant to give up its treasures until over two weeks had passed. Last week I simply substituted new for old, switched on and sat back to be hit with a huge soundstage and a very much tighter bottom end. The trademark organic presentation, pace and timing are there too.

First disc I played was Verdi’s Requiem with the Orchestre Revolutionnaire et Romantique and the Monteverdi Choir conducted by John Eliot Gardiner (Philips, 1995). Quite apart from being one of my all-time favourite pieces of music, it’s a very telling illuminator of audio gear because of its huge dynamic range and use of mass (i.e.: huge) chorus, tempered with solo male and female voices. The 3.1 Balanced immediately threw a much larger soundstage than the 3.1 Signature; bigger not just in depth, but height too. For the first time, I was aware of the boundaries of the space in which the chorus and orchestra are performing. It was also immediately obvious that placement of instruments and vocalists is more confident, the balanced DAC giving them a palpable three-dimensional quality. Parts of Requiem are really quite busy, with the chorus and orchestra at full cry being punctuated by violent, hammer of doom blows on an immense drum. The Balanced DAC deals with all this mayhem with aplomb, whereas the single-ended version got rather flustered.

Not having bat ears or wonderful powers of discernment, it’s impossible for me to say how much of what I hear is pure DAC, and how much is DAC interacting with the rest of my audio gear, and with the room. Either way, the Bryston BP25 pre-amp, and 7B ST power amplifiers – run balanced, as they were designed to be run – and PMC IB1 monitors, treat the extra information they are getting with respect. It should be noted here that my amplification/speaker chain could hardly be further from the Audio Note ideal of low-powered SET, zero-feedback amplification and rather individual design of speakers (see Web site). Nonetheless, it speaks volumes that the company’s DAC technology can be teamed, in my view to very great effect, with such a ‘non-approved’ system. Right or ‘wrong’, the combination delivers an exciting and dynamic musical experience. If the source material is good, something magical happens.

Listen to anything from the Lindsays’ new set of Beethoven string quartet recordings on ASV and the 3.1 Balanced puts you in the front pew at Wentworth Church, just feet from the four performers. Instruments sound resinous, woody, weighty. Players breathe hard with the physical demands of the score. The music and the emotion are alive.

Different performers, different genre (and a studio setting), but on Guitar Trio, (Verve 1996), MacLaughlin, De Lucia and Di Meola are spellbinding, the DAC enabling my system to reveal three extraordinarily talented musicians morphing with their instruments to produce the performance of a lifetime. You hear seemingly living instruments played with power, delicacy and such exquisite timing.

Over the last week, played constantly, the DAC has, as expected, become still more open and sweeter. Once things have stabilised, I’ll try some alternative output stage valves. The little Philips bottles are competent, I am told, but there are better to be had.

How one responds to music is hard enough to articulate and all too often pretty meaningless to other people. I guess for me the killer quality of the new DAC is its sheer musicality. That’s the highest complement I can pay any piece of audio equipment.

Audio Note UK’s owner Peter Qvortrup knows he’s got a good product in his family of D to A converters. He has remarked flatly: ‘…transformer-coupling works. Now imagine a device with a transformer at every gain stage!’

Audio Note’s preferred route may not be the only way to make CD sound passable, but in my opinion it’s a route long overdue some real recognition and respect.

KevinF

Associated gear
Bryston 7B ST X 2
Bryston BP 25
PMC IB1 Monitors
Kimber high-current mains cables
Russ Andrews Purifier distribution block (Kimber)
Kimber Select interconnects/speaker cables