Upgrading the Sound from Your PC
September 5th, 2009 -- by default
Source: The Absolute Sound
Suppose your mind is captivated by the possibility of using your PC as a music server, but your system is saddled with an ancient—that is, more than a year old—DAC that does not support USB. Short of buying a whole new DAC, are there other options? Don’t worry; Bel Canto’s got your back. The company recently released the USB Link 24/96, a cleverly conceived USB-to-S/PDIF converter that is less expensive, more flexible, and better-sounding than the alternative of a USB DAC.
Even those who never made it through PCs for Dummies will have no trouble installing the Link. The size and shape of an aluminum cigarette pack, the device has no controls and sprouts but one USB input and one BNC S/PDIF output. Bel Canto generously packages the Link with a short BNC-to-BNC S/PDIF cable as well as a BNC-to-RCA adapter. Simply connect that cable between the Link and your DAC, snake a USB cable from your PC to the Link, and you are pretty much ready to roll. No need to load any drivers, or even to plug the Link into a wall since, like many USB devices, it draws its juice from the host PC. You must, however, point your operating system’s audio output to the new device—a simple process. Once in operation, the Bel Canto invisibly goes about its business.
That business, of course, is not just reconciling formerly incompatible PCs and DACs, but doing so in a musically satisfying way. In this, the Link has some long odds to overcome since its raw material is the sonically challenged USB interface. Fortunately, the Bel Canto does a fine job of moving the sound significantly closer to good S/PDIF.
Indeed, in every system I tried, having this converter in the loop actually sounded better than directly connecting a PC to a USB DAC. How, you ask, can that be? Isn’t it always best to have fewer boxes and a pure signal path? Normally, yes. But the Link in effect replaces the cheap, off-the-shelf USB input chip found in most DACs with a far more sophisticated and costly module. Then it delivers its payload to the DAC’s S/PDIF input, which is invariably the best-sounding. These advantages apparently outweigh any losses caused by the Link’s conversion process.
To illustrate, consider the sound of two USB DACs with and without the Link. Straight-through USB to the Bryston BCD-1, for example, yields a pallid, airless, “mid-fi” sound. The Audio Research DAC7’s USB input is notably more extended, tuneful, and tonally rich than the Bryston’s, but the ARC in straight-through mode still exhibits flashes of USB’s tell-tale traits: sloppy rhythms, flat dynamics, and a vacuum-sealed soundstage.
Placing the Link in front of either DAC—especially the needier Bryston—substantially elevates the sound. Listen, for instance, to the highly illuminating Dvorák Serenades from Bohemia [Praga] that I used throughout these tests. The Link produces tighter timing, a whiff of fresh air around instruments, tonality captured in pastels rather than black-and-white, and dynamics with hints of actual bloom. Plus, the violins aren’t nearly as irritating. To reap these benefits, be sure to use a good USB cable, such as the Belkin Gold Series ($49.99). And although the supplied Stereovox VC2 BNC cable is quite good, I was able to eke out a tad more air, greater bass authority, and a slightly quieter, more relaxed presentation by swapping in my reference Empirical Design 118 ($105).
Yet for all its superiority to straight-through USB, parity with straight-through S/PDIF eludes the Link’s grasp. The Bel Canto minimizes but cannot completely eliminate USB’s unfortunate attributes. This is not the Link’s fault; it is USB’s fault. Still, the fact remains that where USB through the Link provides whiffs of air, S/PDIF offers pillows. Where the Link elevates USB’s colors to pastel, S/PDIF delivers enamels. And even modest S/PDIF is perfectly capable of steady timing, ripe dynamics, and strings that do not shriek. Partial USB, the Link seems to tell us, is better than total USB; but the best USB is no USB at all.
Unfortunately, if this conclusion holds true for other USB converters, as I suspect it does, it creates a quandary for would-be PC music server users. Once again the question arises: Are there other options? Well, some PCs do have an S/PDIF output, but that is usually TosLink—hardly a step up from USB. At the same time, quite a few PCs include a FireWire interface. In the pro- and home-recording communities, FireWire is the standard for PC audio. These facts led me to wonder how FireWire might compare to USB.