Digital Processor Reviews

When it comes to getting audio from a PC via its USB port, the buzzword du jour is asynchronous. This cryptic term refers to which device has control over the timing of the audio data being streamed from the computer: the computer itself, or the device receiving the data. It might seem logical to have the computer control the timing, but this is not so. When digital audio data are converted to analog by a D/A converter, control over exactly when each dataword is converted is critical for the best quality of sound. Any uncertainty in that timing manifests itself as analog distortion, aka jitter.

The weekly Vote! Page is one of the most popular features of the Stereophile website, and the August 22 question, "Should Stereophile review more or fewer computer-audio products?", generated a record number of responses. No less than 88% of those responding asked for more coverage of products that allow a computer to be a legitimate source of music in a high-end context. Just 7% of readers wanted less coverage.

Lord knows I try to keep an open mind, but those good-measuring delta-sigma chip DACs rub me the wrong way. Their processing complexity vexes my mind, and there's never been a reconstruction or upsampling filter that I've been a fan of. Nevertheless, I believe that every audio component must be judged by how it sounds and feels in use.

While covering CanMania at the 2017 Capital Audiofest, I was sitting at the table of HeadAmp Audio Electronics, listening first to John McEuen singing Warren Zevon's "Excitable Boy," from McEuen's Made in Brooklyn (24-bit/192kHz AIFF, Chesky JD388/HDtracks), then to Macy Gray's Stripped (24/96 AIFF, Chesky JD389/HDtracks). I was listening through HeadAmp's extraordinary GS-X Mk.2 headphone amplifier ($2999–$3199), but midway through Gray's "I Try," I stopped, pulled the Audeze LCD-4 headphones off my head, and asked HeadAmp's head of sales and marketing, Peter James, what DAC he was using.

"Do you know the HoloAudio Spring DAC?"

No history of the computer-audio marketplace could be complete without some mention of High Resolution Technologies, the California company whose Music Streamer was, in 2009, the first perfectionist-quality USB digital-to-analog converter to sell for as little as $99. One could argue that HRT's entire business model has contributed to shaping our attitudes toward the hobby: Because digital-audio technology continues to evolve at such a rapid pace, HRT has introduced a succession of newer and ever more effective Music Streamers, occasionally to the obsolescence of their predecessors; yet because those products have all been so affordable—remarkably and laudably so, given their thoroughly American provenance—we tend not to mind.

Every now and then an affordable product comes along that's so good, even wealthy shoppers want it. Past examples in domestic audio include the Rega">http://www.stereophile.com/turntables/184rega">Rega RB300 tonearm, the original Quicksilver Mono amplifier, the Grace F9E phono cartridge—even Sony's unwitting CD player, the original PlayStationhttp://www.stereophile.com/cdplayers/708play">PlayStation;. Based on word of mouth alone, one might add the HRT Music Streamer+ to that lauded list.

My little corner of Brooklyn happens to have a terrific little record shop. I like it for the usual reasons: well-chosen merchandise, fair prices, fun music on the speakers while you browse. But I like it just as much because great record stores tend to resemble one another in more idiosyncratic ways, and this one has the earmarks of the great record stores of my youth.