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Positive Feedback ISSUE 69
september/october 2013


Musings on Building a Digital Music Server: When Low-Res is High-Res and the Audio Note DAC 4.1x Balanced Signature
by Andy Schaub


"There is no pain you are receding
A distant ship, smoke on the horizon.
You are only coming through in waves.
Your lips move but I can't hear what you're saying.
When I was a child I had a fever
My hands felt just like two balloons.
Now I've got that feeling once again
I can't explain you would not understand
This is not how I am.
I have become comfortably numb."

—"Comfortably Numb" by Gilmour/Waters


First of all, none of this makes any sense at all; and that's pretty much true of every experience I've had with Audio Note equipment. They march to a different drummer, ignoring every trend, disregarding what some people would regard as sound and necessary engineering principals, and just making really excellent sounding equipment. For years, I've been trying to get my digital music server to sound as good as the rest of my system with some limited success but mostly with the attitude that, "Well, that's the digital music server. I guess that's just how music downloads sounds, regardless of their resolution." Finally, Nick Gowan of True Sound in Campbell, CA convinced me to borrow his Audio Note DAC 5 Signature and try it in the DMS (Digital Music Server) for a day, downsampling everything to 44.1kHz in Audirvana Plus and, maybe, truncating my 24 bit downloads to 16 or 18 bits. It's not clear exactly what the Audio Note DAC's do with higher-resolution data; although, I have seen some claims that they can handle up to 24/96 files, and my own experience has borne that out to be true, not that that's necessarily when they sound best.

In any case, we installed Nick's DAC 5 Signature in my system and I started playing files of all different resolutions through it, always downsampling them to 44.1kHz and always letting the DAC 5 Signature truncate the data to 16 or 18 bits, assuming that it actually does that. I have to say, I was very impressed. I got some of the most musical sound I have ever heard from the DMS through the DAC 5 Signature, regardless of the inherent resolution of the source files (most of which were in the ALAC format). Finally, after much grinding of teeth, running of spreadsheets, and taking an inheritance from a wealthy aunt into account (I'm not joking), I decided to purchase what Nick recommended for my system, which was the Audio Note DAC 4.1x Balanced Signature. It's a nice match for my Oto Phono SE Signature and has the chops to do 98% of what Nick's rather magical DAC 5 Signature did, for a lot less money (although it was still profoundly expensive). I can't tell you how much it costs because I honestly don't know. Audio Note is currently updating their price list and the final results are still anyone's guess; but think of something in the dCS Vivaldi range (the DAC by itself, not the whole stack).

Although it technically shouldn't work, I was able to run both my Audio Note CD 3.1x/II and the DMS into the DAC 4.1x at the same time using a Cardas RCA-to-XLR adapter that I happened to have to feed the S/PDIF signal of the Sonicweld Diverter HR (the original one, not the Mk. II), into the AES/EBU input of the DAC 4.1x. I tried this with Berkeley Alpha Series 2 DAC and it couldn't get a lock; but the Audio Note didn't seem to care. I can't have the CD player (now being used as a transport) and the DMS play music simultaneously or even be turned on at the same time; but I can leave both connected at the same time, which is a tremendous convenience since there's not much room for me to reach around and connect different S/PDIF cables given where the DAC 4.1x is located (on my right, main stand, on top of my Equi=Tech balanced transformer). Yes, there is some concern that the transformer in the Equi=Tech will dampen the transformers in the DAC 4.1 Balanced Signature; so we are looking for some Tl-Shield™ (which may not be in production anymore) or some MuMETAL® sheets or foil to put between the two devices to block any electromagnetic interference. It's just not clear that it's a problem yet.

I had to move the Harmonic Technology Magic Power Cord from the Berkeley DAC to the DAC 4.1x and had to move the Audio Pallas digital cable (with Eichmann Silver Bullet Plugs) from the Diverter HR to the digital output of the CD 3.1x/II; fortunately, I still had some Locus Design cables in my cable basket, so I put a longer Keynote AC power cable between the DMS's Equi=Tech and the Berkeley DAC and put the Core S/PDIF cable (with BNC connectors) between the Diverter HR and the Berkeley DAC. I think it made for better sound overall with both the CD playing system and the DMS (when I'm using the Berkeley DAC) so it was a good thing in the end. Lee Weiland, the now-deceased founder of Locus Design, would be proud. The problem is that I had to find some way of connecting the Diverter HR to the DAC 4.1x (Cardas adapter not withstanding). Because of the distance (about five meters), I had to go with a studio-quality S/PDIF cable rather than an audiophile-quality cable because the S/PDIF cable had to have extra shielding, etc. Fortunately, I stumbled across the Apogee Wyde Eye WE-RR S/PDIF cable, which is terminated at both ends with RCA connectors, comes in a five-meter length, and is blessed by Josh Heiner, the creator of the Diverter HR. Plus, it only cost $89.00 at, a real bargain in the audiophile world. Truthfully, it sounds great, even with my Berkeley DAC; but the Core edges it out a little. It's just the Wyde Eye WE-RR is well shielded, quite flexible, and comes in a nice shade of purple; so what's not to like?

While I can plug in the Berkeley DAC anytime I want just by swapping cables on the Diverter HR and get "real" high-resolution sound, I haven't felt the need to since I got the DAC 4.1x Balanced Signature; even downsampling to 44.1kHz, it's by far the best sound I've ever gotten out of the digital music server. I may even replace the Alpha Series 2 with the Ayre QB-9DSD. I feel that I need to have a mainstream DAC in the system for reviewing and comparison purposes and the new Ayre is supposed to be quite remarkable; plus, since Acoustic Sounds launched it's DSD-download business, I think the format may have some staying power and I would like to be able to decode the files natively rather than converting them on the fly to PCM via Audirvana Plus, again, mostly for reviewing purposes; but I digress. I haven't had a lot of time to listen lately; but I did download the 16/44.1 ALAC version of Antonio Lysy at The Broad: Music from Argentina from the Linn download site. On my Woo WA7/Silver Dragon LCD-2's at work, it sounded OK, quite good as a matter of fact; but I really didn't understand what all the fuss was about. However, last night, when I played it through the big system using the DMS and the DAC 4.1x, I was truly stunned. I don't think I've ever heard music sound that well through my system, or really any system, and I really got why Harry Pearson likes it so much. I was truly, jaw-droppingly impressed. While sound quality varies from recording to recording, and some argue that I am crazy for downsampling everything to 44.1kHz, it really works. The DAC 4.1x Balanced Signature is that good; and, in the end, it really is supposed to be about the music.

I've been listening to music all morning. I currently have the 24/96 download of Siwan playing, an ECM recording that I downloaded from It sounds great on my Woo WA7 at work; but—even downsampled to 44.1kHz—it's truly magical going through my DAC 4.1x. Only vinyl might sound better, or just an exceptional CD playing through the CD 3.1x/II as a transport going through the same DAC 4.1x; however, I have to say, when it sounds this good, you stop thinking about numbers and other formats and just sit back and enjoy the music. While Audio Note doesn't publish much about their equipment, I grabbed this from their website about the DAC 4.1x Balanced Signature, "As DAC4.1x Balanced in DAC5 chassis but with better I/V interfaces and Audio Note™ silver wired filters, original NOS Telefunken 6463 output stage with 5:1 step down double C-core copper wired output transformers with balanced XLR input and output and valve stabilised power supply with choke filter and 6X5 HT rectifier". Since it references the non-signature version, I grabbed this as well, "D/A converter. Selected AD1865N chip with 1xoversampling™ direct from disc™ technology with silver wired and patented Audio Note™ I/V transformer interface and digital input transformer. 2 x 5687 NOS double triodes coupled to a custom made 5:1 Audio Note™ copper wired output transformer with thin lamination HiB double C-cores with both XLR and high grade Black Gate™ capacitors and Audio Note™ tantalum film resistors everywhere, separate digital and analogue mains transformers and power supplies with 6X5 rectified choke power supply". What it doesn't say is that Audio Note doesn't believe in output filtering of any explicit kind, no analog, no digital; so, again, they are truly basing their designs on what sounds best regardless of what some would regard as basic, necessary engineering principals; and I applaud them for that.

Audio Note DAC 4 Balanced Super DAC

To listen a little more closely, I fired up my Woo WA6-SE headphone amplifier with my unmodified Fostex TH900 headphones and loaded a new, 16/44.1 download from Linn onto the digital music server, specifically the Dunedin Consort performing J.S. Bach: Six Brandenburg Concertos. Although the download is available in higher resolution, it makes more sense for me to buy the 16/44.1 version since I'm downsampling everything anyway and it saves money (and space), plus I can put the same download on my iMac and sync it to my mobile devices. I'm not saying that high resolution downloads are bad; in fact, I will be doing some comparisons with the Berkeley DAC. It's just that the Audio Note DAC doesn't really care and seems to sound exquisite with lower resolution material. So, bearing that in mind, I started to play J.S. Bach: Six Brandenburg Concertos. Again, the clarity is outstanding but not in an analytical way. The music remains sweet but not euphonically so. Everything falls into place and I feel very much like I am attending a live performance. I can imagine each instrument being played by a member of an ensemble, and the whole ensemble comes together as if in a live performance. I've heard the Brandenburg Concertos many times, by many different groups, almost to the point where I immediately assign to the "background music" category; however, with the digital music server, using the Audio Note DAC 4.1x Balanced Signature, it really comes alive and I hear nuances in the performance that would normally evade me. That's what Audio Note brings to the table and why I spent so much money on this "low resolution" DAC. I just want to keep listening to the music; and that's what it's really all about, at least for me.

So now comes the time to do some comparisons. For my main point of reference, I choose the 24/192 download of reVisions: Songs of Stevie Wonder by Jen Chapin originally downloaded from (I think). It's not my favorite album musically; but it's not bad, and it sounds really great when played through the Berkeley DAC at full resolution. So I'm curious as to how it will sound when downsampled to 24/44.1 and played through the Audio Note DAC 4.1x. I'm still listening with headphones, just to hear every nuance in the recording. Quite honestly, it sounds amazing. It's a little softer and sweeter than the Berkeley DAC but not euphonically so and I hear more air or ambience around the instruments without sounding Spectral-ish (not meaning to slam my former reference equipment from the mid to late 1990's). The horns have a distinct "honkiness" and the bass has a nice sense of "pluck"; plus, Chapin's voice is amazing and, for the first time, I really begin to appreciate the quality of her performance on this recording. Plus, the whole ensemble begins to come together and, although it's clear that this is a studio recording, there is more of a sense of cohesiveness to the individual performances. I could really listen to this for hours. I also choose John Ward: Consort music for five and six viols by Phantasm downloaded at 24/192 from, I think, the Linn website. While this is an impressive sounding recording via the Berkeley DAC, it has an edge to it that it makes it difficult to listen to and the individual performers sound somewhat disconnected from one another. Via the DAC 4.1x, downsampled to 24/44.1, it's much easier to listen to and the sound is definitely more holistic.

Next, given that I miss the Magnum Dynalab MD 807T Internet Radio Tuner that I reviewed a few months ago, I wanted to see if the DAC 4.1x Balanced Signature would make iTunes radio more tolerable through the digital music server. Given that I had to remove Audirvana Plus from the equation to do this, I manually set the sample rate to 24/44.1 in Apple's Audio Midi Setup, and then choose WFMT in Chicago from the list of available stations in iTunes radio, a really great classical radio station that I remember from my graduate student days at Northwestern University. While it doesn't have quite the warmth and magic of the MD 807T, it comes much closer and I can see myself actually using iTunes radio to listen late at night to, say, WFMT or BBC Radio 3, not to mention more local stations like the great jazz station, KCSM or even talk radio like KALW right out of San Francisco. I want to make it very clear though that, even given the dCS Vivaldi-ish price of the Audio Note DAC 4.1x Balanced Signature and everything I've done to optimize the sound of the digital music server, there is some magic to the Magnum Dynalab Internet Radio Tuners that the digital music server just doesn't share and although I will be far more inclined to listen to Internet radio given the addition of the DAC 4.1x, someday I have to buy an MD 807T for myself. I don't know what secret sauce Magnum Dynalab uses, but they do get radio right.

Lastly, I really had to proceed to the acid test, which is my 24/96 download of The Köln Concert by Keith Jarrett from I know that I wrote that using the Galileo MPC with my Synergistic Research USB cable made for a substantial improvement with the Berkeley DAC; and that's still true. However, using the same arrangement with the Audio Note DAC 4.1x Balanced Signature—even downsampling to 44.1kHz—really leaves pretty much everything except for my German vinyl pressing in the dust. There's an analog-like flow to the music that I just haven't been able to get out of the digital music server until now. The notes seem to just lift off of the keyboard and dangle briefly in midair until dissipating into the ether. Jarrett's stomps, growls, and hums fall properly in proportion to the music; and I can't say that I hear anything that sounds particularly "digital" about the recording now. I find myself focusing on the music and not the sound and am reminded of when I first heard this album in the late 1970's at my freshman dormitory at Stanford. Surely I had a lesser system then; and, in some ways, there seems to be something rather absurd about the fact that I have to put this much time and this much equipment in recreating that event. However, the bottom line is that it works; and I suppose in this crazy, obsessive-compulsive hobby that we call being an audiophile, that's the payoff that you occasionally get. Now I just need to put together that playlist of Bach's Mass in B minor, or sample the whole Ring Cycle via my Apogee Duet 2 and play it back through the digital music server. Has it been worth this much time and effort? Strangely, yes; and I'm not sure there's much more to say than that.

Kindest regards,