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
kevingf
FYI,
The unit is still transformer coupled even when run single ended. In fact Peter Q. Runs his single ended. The transformer coupling makes a world of difference.
Very well written review. I only own the Audio Note cd player. It is outstanding. I can only imagine how good the DAC is. I have heard the transormer coupled pre amps and know that this technology makes a difference.
JC do you also agree this sounds better than the 3 Signature even in single ended mode?
I just got my 3.1x balanced a few days ago. It is everything the reviewer said and more. I like listening to digital now.
Very natural, great soundstage,supremely extended dynamics and no digital GLARE.
I have an original DAC 1 Signature. My neighbour who has a 5 figure Levinson DAC likes the sound of this early 90's better than his Levinson. A DAC 1 for less than 700 has to be a deal of the year.

Go figure.

Regards,
Carl
Kevin,

You have set a new standard for reviews and thank you for your time. I write only to say as an Audio Note 3.1X Signature owner, that I have compared the Audio Note 1.1X Sig to the Audio Logic 2400 at $4,500 (as well as several others) and within seconds new the AN to be superior to the AL for transparency, lack of sibulance and true bass reproduction...at a third of the price!

As you may have discerned, I am an Audio Note champion. Well, the story goes on. Each Level on the Audio Note ladder provides new horizons of fulfillment in hifi reproduction and for the following reasons: (1) an adequate power supply, (2) finer quality transformers, (3) Black Gate capacitors which have their own performance Level ladder. I recently read a review of Black Gates and what it is about this unique capacitor in a British publication, maybe it was Hi-Fi News.... Anyway, an Audio Note has to be heard to be believed; at least, that was my experience.

Regards,
Skeptical Jim.
Sorry I am just getting back to your question now regarding the 3 Signature and balanced unit.
The 3.1 Balanced is a 3 Signature in a DAC 5's larger chassis with the metal curcuit seperator but primarily the transformer coupling. As with his preamps, transformer coupling does make a difference.
Having said that I will say that a 3.1 Signature is still one of my favorite piieces in the digital line up from Audio Note. At $1000 less it is still a bargain. Not to hurt my sales but if you can find a 3.1 Sig. used on the Gon. Call me with the serial numbers and I can tell you if it is up to date. The Signature versions are without a doubt much better than the standard version 3.
I have read reviews of the Audio note DACs which say that, due to their high output impedance they may not work well with amplifiers with an input impedance less than 50k ohms. Since my integrated has a passive preamp with an input impedance of only about 25k ohms I have previously dismissed the idea of the audio note dacs, even though their "minimum processing" concept appeals to my minimalist tendencies.
Can anyone comment on the impedance issues, and whether it is a non-issue, or a real issue ?
Hi Sean,
I attached some interesting threads from Peter of Audio Note and Ralph from Atmosphere regarding transformer coupling and impedance. The trnasfromer issues are the same when utilizing the gain stage of the Dac directly as it uses the same technology. Hope this helps.

Responses
Click title to read one, or click date to read all below it.

08-14-02: Jcaudio
THE THREAD ACTUALLY STATED THE OPPOSITE! Most manufacturers utilize capacitor coupling. Very few use transformer coupling as it is expensive and time consuming.
The most unusual feature is line output stage, which is configured as a small power amplifier stage with a 5687WB double triode per channel. An output transformer is then coupled to the output signal which serves as an interface to the power amp being used. This allows the pre-amp to utilize not only two sets of single ended RCA outputs but also a 600 Ohm fully balanced output using a Lemo type connector. This unique way of transformer coupling the output stage means that the pre-amp can be used with any power amplifier whether valve or transistor.

Transformer coupled pre-amps are much more expensive but in all the shootouts we have done here are much better. I have attached one of those posts where a passive device (several) were compared to transformer coupled pre's. In addition we have done shootouts with pre-amps that were capacitor coupled costing as much as $15,000. always with the same result.

Why do the Audio Note preamps sound so much better
I took Joe over at JC Audio up on the offer of a shoot out. Actually it was the second time. About nine months ago I went over and had a shoot out between my EVS Nude Attenuators and the Kora triode preamp. I have to give Joe credit he agreed if you could live with the inconvenience and lack of flexibility that the EVS attenuators sounded as good.

But I made a bad mistake today. I went over and did the same shoot out with the Audio Note M5. I should have never done this. The M5 made the attenuators sound dry and lifeless. The M5 sounded prettier with much more top in extension without ever sounding bright. It was more transparent and fuller bodied at the same time. And the layering and the soundstageing was just beautiful. This is disturbing to me for I have been a big proponent of passive, especially the attenuators since you even eliminate a set of interconnects and a power cord. Why does this line stage sound so much better.
bilbondo@hotmail.com

08-02-02

Responses
08-02-02: info@audionote.co.uk
Dear Bilbondo,

Why??

Quite simple, in the M5 (and all our other transformer coupled pre-amplifiers, the M3, M6 and M8), there are no impedance mismatches, there is more than sufficient gain to maintain the dynamic envelope of the signal intact combined with a natural (meaning not created artificially by feedback or other trickery!) drive impedance so low as to render the load (the power amplifier input) irrelevant.

The disadvantage is cost, you heard for yourself the sonic advantage.

Sincerely,
Peter Qvortrup

Jcaudio (Threads | Answers)

08-14-02 Peter, what would you say on passive transformer-couple ... Marakanetz

08-14-02 You could not do transformer passive. that is impossibl ... Jcaudio

08-14-02 here is a discussion of a transformer based "pre ... Clueless

08-14-02 Interesting article. learn something new every day. unl ... Jcaudio

08-14-02 Interesting article. learn something new every day. unl ... Jcaudio

08-14-02 Jc, sorry about my confusion. i guess i am not only ha ... Khokugo

08-14-02: Jcaudio
The issue is more than just impedance. As capacitors drain during dynamic passages you will hear it as strained or harsh sounding. In addition, many manufactureres use cheap capacitors. That being said even the best have a sonic signature. I will include the post here for you.

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Why do the Audio Note preamps sound so much better
I took Joe over at JC Audio up on the offer of a shoot out. Actually it was the second time. About nine months ago I went over and had a shoot out between my EVS Nude Attenuators and the Kora triode preamp. I have to give Joe credit he agreed if you could live with the inconvenience and lack of flexibility that the EVS attenuators sounded as good.

But I made a bad mistake today. I went over and did the same shoot out with the Audio Note M5. I should have never done this. The M5 made the attenuators sound dry and lifeless. The M5 sounded prettier with much more top in extension without ever sounding bright. It was more transparent and fuller bodied at the same time. And the layering and the soundstageing was just beautiful. This is disturbing to me for I have been a big proponent of passive, especially the attenuators since you even eliminate a set of interconnects and a power cord. Why does this line stage sound so much better.
bilbondo@hotmail.com

08-02-02

Responses
08-02-02: info@audionote.co.uk
Dear Bilbondo,

Why??

Quite simple, in the M5 (and all our other transformer coupled pre-amplifiers, the M3, M6 and M8), there are no impedance mismatches, there is more than sufficient gain to maintain the dynamic envelope of the signal intact combined with a natural (meaning not created artificially by feedback or other trickery!) drive impedance so low as to render the load (the power amplifier input) irrelevant.

The disadvantage is cost, you heard for yourself the sonic advantage.

Sincerely,
Peter Qvortrup
info@audionote.co.uk

08-02-02: Rcprince
Some will call it tube colorations; it's the classic music vs. accuracy debate. FWIW, I have always preferred components which deliver a realistic reproduction of what I think the recorded performance/musical event sounded like rather than what the master tape sounds like; after all, if you listen to performances from Row J in the orchestra section of a concert hall it'll sound quite different than what you'd hear if you sat where most microphones are placed. I think my Jadis preamp falls in that category, and perhaps the Audio Note does as well.
Rcprince (Answers)

08-02-02: Trelja
Rcprince hit the nail on the head. As usual.

I am a huge fan of Audio Note. No, it is not cheap. But, like Jadis, I believe it offers REAL value. That is because it is one of the few marques that can be considered a last purchase. The purchase is made, the component is inserted, and it is simply enjoyed. Hour upon hour, year after year. They are not for audiophiles so much as music lovers. They are not meant to impress in terms of calling attention to themselves. They are components who want music to sound like music; real, natural, organic.

To my love for the components of Audio Note and Jadis, I have also found the same thing true of my Blue Circle preamp. Just as Peter described of the AN, I have found in the BC preamp. I doubt I will ever sell my Jadis or Blue Circle components, they are lifetime companions. And, one day, I will also own an Audio Note pre or power amp.
Trelja (Threads | Answers)

08-03-02: Jcaudio
I would like to thank those members who took the time to take me up on a shootout between passive devices and transformer coupled pre-amps. Thanks again
JC Audio (Threads | Answers)

08-03-02: Jdubusc
I will concede from the outset that I have a bias, forgive the play on words, for I am an AN owner. The point I wish to make is regarding my experience with two passive preamps: the EVS attenuators and the Placette passive preamp. IMHO, I found them both to be anemic, profoundly anemic, as compared to my Audio Note M-5. The differences were not subtle! Good Listening, Jim.
Jdubusc (Answers)

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Jcaudio (Threads | Answers)

08-14-02 Hi jcaudio: i agree, if you have a transformer i think ... Clueless

08-14-02 Clueless, i believe per the article that the transforme ... Jcaudio

08-14-02 Jc: i'm about as "local" as you can get. i ju ... Clueless

08-15-02: ralph@atma-sphere.com
The Audio Note, EAR (E11??), the big Jadis and Atma-Sphere (P-2) preamps are the only high-end audio transformer-coupled units out there to my knowledge.

Transformer-coupling is common in professional tube gear, particularly from the 50s and 60s. This is because the equipment had to match to the 600 ohm balanced line standard (which is still very much around today). Tubes coupled by output coupling capacitors would never be able to play any bass driving a 600 ohm load!

We built the P-2 (discontinued when it was replaced by the MP-3) so it could drive the 600 ohm standard as well. The nice thing about the 600 ohm standard is that it ameleorates the role that interconnect cables play in the sound of the system, which is why the standard has been used for the last 5 decades by the professional recording and broadcast arts. Its always been a puzzle to my why audiophiles are so slow to embrace the same standards, despite having the same concern about cable qualities. This has spawned the high-end audio multi-million dollar/year cable industry.

We're an OTL manufacturer, but we've been a major supporter of balanced line technology for the last 14 years (mostly due to prolonged exposure to the recording studio); our preamps support the standard using direct-coupled ouptuts, which is the only other way to do it as capacitors won't work (since no-one would take a tube preamp with an electrolytic output coupling cap seriously...). IMO, its a shame that more manufacturer's aren't wise to what's happening here (sorry for the hype blast).
ralph@atma-sphere.com


By the way. The output impedance of their non transformer coupled DAC's is around 2K ohm with 3 volts output.
thanks for the response. I'm moving back to England next year so I'll try to demo one when I'm there. I'll only be batting at the zero level due to exhorbitant house prices (here and there) and a 1 year old to look after.
Sean

Today is September 25. The 3.1 Balanced has continued to improve.

Others have noted the sometimes extraordinary time it takes Black Gate capacitors to settle down and it may well be that since the 3.1 Balanced uses several, they exert an overwhelming influence over the total performance until fully run in.

Either way, the DAC has now run for some 700 hours and I am moved to add very little to my comments in the main review. The changes have been subtle: bass has tightened a little and top end has got smoother. I can't say that sound staging has improved much further, if at all.

Readers may (they may not!) be interested to know that I have played around a little with alternatives for the Philips JAN 6DJ8 valves that drive the output stage. Audio Note's advice is that while there are gains to be had, changing valves makes less difference than changing cables.

Since I already use a Kimber 75 Ohm digital feed to the DAC and Kimber silver balanced output to the pre-amp. I was not minded to make changes here. But valves.... well, they're easily and for the most part pretty cheaply sourced.

Mullard E88CC Gold Pin (England April 1969): A very wet sound compared to the Philips with a flabby bass and rolled off high end. Sound stage was bigger than the Philips, but overall I felt these were (in this DAC) a surprising disappointment. Both valves alarmingly microphonic.

Siemens E88CC (Audio Note supplied): A noticeably more liquid presentation than the original Philips. Make the DAC sound even more analogue. One valve microphonic when gently tapped, one not.

Siemens E188CC Gold Pin 7308. (date code on tag inside glass envelope, but I can't find my spyglass to read it): I imagine these to be late manufacture, since they have a halo getter but no spatter shield. More liquid still than the Siemens E88CCs, but with an even tighter bass and a more finely drawn soundstage. There is no microphony.

I was keen to try the 7308s since they have such a strong reputation among tube rollers. Having done so I can understand why they command top prices.

Enough for now.