February 1, 2010

Bel Canto Design DAC3VB Digital-to-Analog Converter and VBS1 Power Supply

Last summer I reviewed the Bel Canto e.One DAC3 D/A converter and CD2 CD player on SoundStage!, our sister audio site. Together, they produced the best digital sound I’d heard through my system up till then. So when the offer came to try an upgraded version of the original DAC3, the DAC3VB, with its new VBS1 (for Virtual Battery Supply), I was happy to oblige. Still, I found myself wondering how much better things could really get -- parsing the minuscule differences between completely different DACs can be challenging enough; comparing an already accomplished DAC against its next iteration, the only difference being the power supply, already had me reaching for the Q-tips.

VBS1

See my August 2009 review on SoundStage! for a description of the e.One DAC3 -- the only changes in the e.One DAC3VB ($2695 USD) are the latter’s upgraded power-supply board, and a revised power connection made specifically for use with the new VBS1 power supply ($1495) or LNS1 (Low Noise Supply, $495) also available from Bel Canto.

Bel Canto’s design goals for the VBS1 were to provide electrical isolation, energy storage, low impedance, and high peak current. At first they tried a linear-based, toroidal power supply, but ultimately found significant sonic and environmental advantages in switching to a low-noise, switch-mode power supply (SMPS). The SMPS is said to provide over 90% energy efficiency (the DAC3VB needs only half the amount of power the DAC3 did) and permits specific control of operating parameters of the supply, high levels of isolation, and significantly lower audioband noise than traditional, 50/60Hz transformer-based supplies. The SMPS is claimed to reduce low-frequency noise by a factor of +100. While this type of supply generates more high-frequency noise (from 100kHz to several MHz), Bel Canto found it much more effective to attenuate this noise and remove it from the audioband than the low-frequency type.

The SMPS is also said to permit the use of a transformer 100 times smaller than its toroidal brethren, and can get away with using very few turns of large-gauge copper wire. Also, rectifying 50/60Hz power generates a lot of noise that’s said to create a host of harmonics at double the frequency that run up through the critical midrange. Another benefit of using the SMPS is the avoidance of having to use large inductors and capacitors to deal with this noise, which is now shifted to very high frequency ranges, where it can be removed by smaller, more efficient filters. This strikes me as similar in concept to increasing the digital sampling rate to move the operation of the "brick wall" (or whatever type of) filter far beyond the range of human hearing.

Anyway, to put some numbers to all this, the VBS1 is said to be 10x to 100x lower in noise than a traditional linear power supply -- in short, lower than the output of an analog preamplifier. On the filtration side, Bel Canto states that the VBS1 provides more than 100dB of isolation and filtration starting well below 100Hz, offers more than 100 Joules of energy storage, and ensures hundreds of amperes of peak current capability with a total capacitance of half a farad.

With dimensions of 8.5"W x 3"H x 12.5"D and a weight of 15 pounds, the VBS1 is roughly the same size as the DAC3VB -- the two small components can easily sit side by side on an equipment shelf in the space occupied by a single standard CD player. Like the rest of Bel Canto’s e.One line, the VBS1 is fairly Spartan in appearance, with only an IEC power socket, three unique power-out connections (to be used only with the supplied Bel Canto umbilicals), and an on/off switch on its rear panel. Out front is a lone blue power-indicator light, which in this case is useful for more than just letting you know when the power is on. The capacitors take about as much time to charge and discharge as in my McCormack amplifier, and it’s important to wait for the VBS1 to discharge completely before disconnecting any components from it.

The fact that the VBS1 has three outputs doesn’t strike me as a coincidence. In a complete Bel Canto system it could be used to power an e.One CD2 as a transport, an e.One DAC3VB (which could also serve as the preamplifier), and an e.One tuner -- then you’d have customized power delivery for most of your system. If, in such a system, the benefits were truly additive and consistent with what I heard using the VBS1 with the DAC3VB, this would be an interesting proposition indeed. An e.One DAC3 can be upgraded to e.One DAC3VB status for $595 (though this doesn’t include the $1495 price of a VBS1).

Of course, there would be tradeoffs -- in this obsessive-compulsive hobby of ours, when are there not? On the plus side, the VBS1’s power conditioning has been designed to work specifically with the e.One models. On the negative, the VBS1 provides no surge protection, so for complete peace of mind you’d have to add some sort of conditioner or protector between the wall outlet and the VBS1. Also, buying any Bel Canto product with a VB board installed pretty much commits you to using a VBS1 power supply. That’s fine if you’re the set-it-and-forget-it type, but I know that many of you ’philes out there are always looking to try the next big thing; if someone comes out with a breakthrough power conditioner, those of you who’ve bought Bel Canto VB models will be left watching (and listening) from the sidelines.

The idea for the VBS1 system came from a trip that Bel Canto designer John Stronczer took to France. While listening to a friend’s system there, Stronczer was struck by what he heard. Turns out the system was powered by a 12V lead-acid battery system -- "off the grid," as it were (ironically, the system’s source was a turntable). Wanting to bring better sound quality to his products but not satisfied that the battery solution would fit Bel Canto’s extremely green ethos, he set out to design a power system that would produce largely the same effect without the environmental penalties of acid and a toxic heavy metal such as lead. Thus was born the VBS1. The fact that the VBS1 is relatively small and light, and consumes no more energy than your average preamplifier, is testimony to its success on the environmental front. But what about the sound?

Power does corrupt

Among audiophiles, power conditioning is one of many controversial issues. Some say they achieve best results by plugging components directly into dedicated AC lines, while others swear by their beloved power conditioners. As with most audiophile controversies, many of the differences heard are no doubt matters of personal taste, but how strongly the power supply affects the sound quality will also depend greatly on the quality of the power coming into the house.

I’d been listening to the VB system for two months: one month of casual listening as the units broke in, and another for pure enjoyment -- er, evaluation. But the time had come to plug in my original e.One DAC3, which Bel Canto had allowed me to hold on to for a while. (I’m glad they did -- there’s no way my feeble auditory memory could have recalled its sound.) First, however, I unplugged the VBS1 from my newly installed dedicated line and plugged it into an ordinary outlet so I could get down’n’dirty with both units.

The most startling thing I noticed was . . . nothing. I couldn’t readily hear any significant differences with the VBS1 now plugged into the dirty power source; if anything, I thought the dirty line sounded just a tad more open and transparent. I have no idea why this would be so, but the fact that the outlets sounded so close spoke well, I thought, of the filtration taking place. Essentially, the quality of the outlet did not make that much difference to the VBS1. Of course, all this meant nothing if it didn’t result in a meaningful increase in sound quality over the DAC3. I was skeptical.

But the moment I plugged in the original e.One DAC3 to the same outlet, the differences were dramatic and obvious, though not all necessarily positive. The DAC3 had more of a sense of space and extended reverberation trails; in comparison, these seemed truncated through the DAC3VB. At first I thought the DAC3 was exhibiting a more transparent and revealing perspective, one that I might prefer. Then I switched the DAC3VB back in -- a whole new ballgame. Yes, space and air were reduced, if still there, but those qualities went side by side with a blacker, more silent backdrop that allowed performers and instruments to pop out in a more real and live dimensional sense. Now the DAC3 sounded harsh and flat by comparison -- amazing, because those descriptors hadn’t even entered my mind during the listening for my August 2009 review. The DAC3VB came across as so much more natural, relaxed, and real that I now found it inconceivable to go back to the DAC3. But of course, for perspective and to write this review, I had to. So here we go.

I happened on Sting’s Still Be Love in the World (download, A&M 1486860) at a Wilson Audio Specialties demonstration, and I enjoy listening to it at full volume in complete darkness -- it can really evoke the illusion of a live performance in the listening room. I especially like "Fragile" -- despite the DAC3’s initial apparent spatial advantage, it was the DAC3VB that seemed to spread the entire performance before me; the DAC3 produced a stage that was more focused toward the middle. Sure, there were a few more reverb trails within the constricted center with the DAC3, but so what? It sounded more artificial and contrived, with images that were more placed rather than truly existing where they were. There was also a much fuller and more natural tone to the guitar and vocals through the DAC3VB. The entire experience reminded me very much of comparing 16-bit/44.1kHz processing to a 24/96 or 24/192 version. Those of you who’ve heard such comparisons will no doubt know exactly what I’m talking about. The ease, the effortless flow, the blacker backgrounds, the more realistic imaging and sense of space -- this is the stuff of which true, effortless, and complete musical enjoyment is made.

I had a similar reaction to Usher’s demonstration disc Be There (CD, Weichen Publishing House Co. Ltd., no catalog number), which contains an awesome choral recording, "Madonna." With the DAC3 there was, again, tons of apparent air and space, but the experience was one of choristers singing at me, producing a wall of sound between them and me. Switching to the DAC3VB produced a very different listening experience: the singers were now singing to me from various points in space, in a more layered presentation of depth. My impression was that the subtle differences in volume between the layers were more fully exposed, thus creating more vividly the illusion of a live chorus in my mind’s eye.

And so it went with recording after recording. All I can say is that, as good as the DAC3 is, the DAC3VB was better -- so much so that I most assuredly would not want to go back. It was the difference between hearing excellent sound vs. experiencing a live performance. With ordinary dirty AC powering things, it was a no-brainer -- but therein lay the rub. What had begun as one of the easiest reviewing jobs I’ve had (amazing, considering we’re talking about fraternal-twin digital sources) got a little tougher when I used cleaner power.

Remember how I mentioned that switching the DAC3VB from a dirty to a dedicated line made very little difference in its sound? Well, nothing could have been more different with the DAC3. There was still a clear difference in that the DAC3VB tended more toward dead-silent backgrounds, the DAC3 toward backdrops as transparent as air. But now, through the dedicated line, instead of a wall of sound, the DAC3 displayed dimensional qualities that rivaled those of the DAC3VB. The tonal advantage of the DAC3VB was also largely erased: the differences between such things as the fullness and richness of voices and woodwinds, and the clarity of cymbal strokes, became so small as to test my ability to hear them at all. My job had just gotten a lot tougher.

After listening to recordings spanning many genres, bands, and concerts, it was classical music that finally let me home in on the most meaningful differences. The DAC3 still had a strong advantage in defining space and allowing reverb trails to dwindle completely to nothingness. But I found that this was actually too much of a good thing -- all that bouncing around of sound actually served to obscure rather than reveal spatial relationships. In the end, by virtue of its relatively quiet, subdued backgrounds, the DAC3VB revealed placement and presence of performers more clearly and with less confusion, and on the whole was just easier to listen to. It came down to a comparison of detail for detail’s sake (the DAC3) vs. detail for the sake of communicating important aspects of an actual performance (the DAC3VB). Personal taste could point someone else the other way here, but I unequivocally preferred the DAC3VB’s sound, and suspect that the qualities I heard may have been what inspired John Stronczer to pursue the VB project in the first place.

After identifying these subtle but salient differences with classical music, I could hear them more clearly across the board. On Stevie Ray Vaughn’s "Tin Pan Alley," from Couldn’t Stand the Weather (CD, Epic/Legacy 21044), his guitar and voice popped out of the mix more dynamically and dimensionally. More than that, it was as if the sound of his guitar was being thrust toward me rather than existing in its own space; likewise, the hi-hat and ride cymbals floated more believably as whole and physical presences. Overall, it was dynamically a more nuanced and authentic presentation, and these are the types of qualities I believe people are actually alluding to when they say their systems sound more like live music. These differences can seem subtle, but when recognized, they can make all the difference.

When I tried the DAC3 with an APC AV H15 power conditioner, perhaps not surprisingly, it split the difference between the dedicated line and the DAC3VB. With the conditioner, the DAC3 had blacker backgrounds and subtler dynamic shadings than before, but now less spaciousness and dimensionality than the DAC3VB. So while I’d marginally prefer listening to the DAC3 this way than to plugging it directly into a dedicated line, it still fell well short of what the DAC3VB offered. Take these remarks for what they’re worth -- I don’t consider the APC AV H15 the state of the art of line conditioning, and found it had a similar blunting effect on my two-channel system -- but I thought it useful for comparison purposes.

What does it all mean? Well, as with most issues concerning power conditioning, it really depends. An in-home audition is almost mandatory, because everyone’s power-supply situation is different. If you’re running your system from a nondedicated line with no power conditioning, you simply have to try the e.One DAC3VB with VBS1 power supply to see if the dramatic differences I experienced are possible in your home as well. The DAC3VB significantly and substantially improved the best digital sound I’ve had in my system. If you believe in plugging directly into a dedicated line with no further power conditioning, I’d say there are still palpable benefits to be had that are worth making the effort to hear.

Conclusions

A much trickier recommendation is of whether or not to run a DAC3 into a high-quality power conditioner, and I didn’t have one of the latter on hand. If you’ve found a conditioner that really works for you in the context of your system, this could be a tough call -- you’ve already ponied up for conditioned power. That said, it still may be worth a listen; Bel Canto’s VB approach may offer audible advantages you won’t get from more traditional power-conditioning methods. There’s also the fact that Bel Canto developed this power system specifically for the e.One DAC3, literally from the inside out -- what are the odds that a different company could make an external device that would do better? There’s only one way to find out.

Played through an ordinary outlet sans power conditioning, the Bel Canto e.One DAC3VB and VBS1 power supply, compared to an e.One DAC3, provided a greater difference in sound -- another league, in fact -- than I typically hear between two completely different DACs made by unrelated companies. And that difference was all for the better. With both DACs fed clean power through dedicated lines, the VBS1 system still had palpable advantages that spoke of more than just basic power conditioning.

For those interested in the excellent e.One DAC3, or who may already own one and are contemplating an upgrade, the potential improvements offered by the e.One DACV3B and VBS1 are worth a serious listen -- Q-tips not required.

. . . Tim Shea
tims@soundstagenetwork.com

Bel Canto Design e.One DAC3VB Digital-to-Analog Converter
Price: $2695 USD
Bel Canto Design e.One VBS1 Power Supply
Price: $1495 USD
VB upgrade board for e.One DAC3
Price: $595 USD
Warranty: Two years parts and labor (nontransferable).

Bel Canto Design
212 Third Ave. N., Suite 274
Minneapolis, MN 55401
Phone: (612) 317-4550
Fax: (612) 359-9358

E-mail: info@belcantodesign.com
Website: www.belcantodesign.com