Bratty, mollycoddled, and altogether spoiled consumers such as you and I have inflicted on computer audio the same injustice that laparoscopic surgery, antilock brakes, mobile telephones, word processors, e-mail, microwave ovens, and over-the-counter proton-pump inhibitors have suffered at our hands in recent years: In less time than it takes to say "ho-hum," we've knocked it from the pedestal to which all such breakthroughs are entitled and begun taking it for granted.
Since its founding in 1993, Colorado-based Ayre Acoustics has made its name with amplifiers and preamplifiers based on truly balanced, solid-state circuitry that didn't use the ubiquitous panacea of loop negative feedback to produce linear behavior. Their first digital product was the D-1x DVD player, reviewed for Stereophile by Paul Bolin in February 2003, which offered unusually good video performance. The D-1x was followed by the C-5xe and DX-5 universal players, respectively reviewed by Wes Phillips (July 2005) and Michael Fremer (December 2010). But the most intriguing digital product to come from Ayre was the QB-9 digital processor. Reviewed by WP in October 2009, the QB-9 has just one input, USB, and uses Gordon Rankin's proprietary Streamlength code to give asynchronous operation, which in theory offers the best jitter suppression. "The QB-9 isn't a computer peripheral," said Ayre's marketing manager at that time, Steve Silberman. "It makes computers real high-end music sources"a statement with which WP agreed.
Thus spoke AudioQuest's Steve Silberman, VP of development, of their brand-new USB D/A converter, the DragonFly. "There are a lot of very good DACs out there," he continued. "There are even a lot of very good affordable DACs. But the problem is, people outside of audio don't want them: They don't want old-style components like that.
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.
One of the better digital front-ends I've ever heard was demonstrated for me a number of years ago at the house of an audiophile friend: a Weiss Engineering combo of Jason CD transport and Medea digital-to-analog converter. That front-end remains in my mind as one of the only digital systems I've heard that could compete with the very best that vinyl has to offer while still doing what digital does best. In other words, there were warmth and musicality, staggering dynamics, and real silent backgrounds. When, recently, I saw that the Swiss company had come out with a DAC featuring onboard volume control, a headphone amp, and a FireWire input, I knew I had to give it a listen.
There's so much uncertainty and confusion surrounding computer audio and high-resolution downloads. Which hi-rez formats will win out? How do you store the downloads you've bought? (Easy. Don't buy them.) How do you access them? Will digital rights management (DRM) cramp your style, or data-storage fees for cloud computing crumple your wallet?
I've been reading a fascinating book, Leonard Shlain's The Alphabet Versus the Goddess: The Conflict Between Word and Image (New York: Viking, 1998). Shlain's thesis is that the invention of the alphabet was the cause of immense changes in primitive society, upsetting previously widespread norms of gender equality and horizontal (rather than hierarchical) social relations in general.
Sure, Stereophile gets letters to the editor. We also get some colorful responses for our "Manufacturers' Comments" section. (Vince Bruzzese and Roy Hall are literary standouts among their component-making peers.) And, as one of the magazine's Contributing Editors (Audio), I get lots of personal mail from readers seeking my advice. I thought I might share some of these letters with you, and my responses.
If an audiophile visiting an audio show in 1991 were to have been transported two decades into the future, at first he would not be aware of any difference: A two-channel system would be playing in a hotel room. But on closer inspection, he would notice that the CD player, the ubiquitous source 20 years ago, would be conspicuous by its absence. Yes, there might be a turntable"Good to see that people are playing LPs in the future," he would thinkbut why is there a PC in the room?
The dual subwoofers were bumping and our pant legs were flapping. Only moments before, we'd been treated to a polite viola da gamba. Not now. Resolution Audio's designer, Jeff Kalt, had brought only two discs with him to ensure that his company's Cantata Music Center was functioning properly in my system: Jordi Savall and Hespérion XXI's Altre Follie, 15001750 (CD, Alia Vox 9844), and Tool's 10,000 Days (CD, Tool Dissectional/Volcano 81991). After changing a few things around with the chamber music, we'd advanced to the hard rock of Tool.
Oh boy, another new DAC review. Some folks think DACs, once you get past the features, all sound pretty much the same. I mean, it's just digital. Well, they're right. Pretty much. Just as two new cars of a particular make, model, color, and options package both look the same, sitting there on the lot.
But if you discover a ding in the door of one of them, where most folks still see only a new car, you now see the ding. It might have been there all along, undetected the first few times you walked around the carmaybe your buddy even had to point it out to you. It's insignificant in the scheme of all that a new car is, but once you've seen it, you always see it. Now you can easily tell the two cars apart, and we both know which one you'll drive home.
I don't remember where I was when the Berlin Wall came down, and I already don't remember what I was doing when Liz Taylor died. (I suppose I was busy not thinking about Liz Taylor.) But I do remember when USB-based computer audio became a serious medium: That was when Gordon Rankin, of Wavelength Audio, introduced asynchronous data streaming, with his proprietary Streamlength software. After that, things picked up speed.
As metaphors go, the silver bullet is somewhat ambiguous, given that it's used to represent both the reliably destructive and the reliably beneficial. (Who would have guessed that an idea from a Lon Cheney Jr. film would prove too subtle and complex for people in the 21st century?) Nevertheless, at Montreal's Salon Son et Image on April 2, those of us who comprised Stereophile's reliably responsive "Ask the Editors" panelJohn Atkinson, Robert Deutsch, and Ivolleyed it with the sort of sprightly, vernal abandon that is the sole province of men with gray hair. To wit: We agreed that no materials, technologies, or design decisions can either guarantee or prevent good sound. Not vinyl. Not star grounding. Not class-A circuits. Neither tubes nor transistors. Neither belt nor idler nor electrostats nor multiway nor single-driver nor copper nor silver nor silk nor beryllium. Not even harmonic distortion. Each of those ideas may mean something to someone, in the short term, in the narrow view, but that's all. There are no silver bullets.
"We like to make things," Roy Gandy, Rega's founder and owner, once told me. "It's what we do." Or maybe it was Rega's chairman and chief engineering honcho, Terry Bateman. Rega products are designed and manufactured in the south of England. So far as I know, no one at the Rega facility, on the Temple Farm Industrial Estate, has committed suicide; the same cannot be said of workers at the factory in China where iPods are made. Al Gore is on the board of Apple. Al, what do you think?
A computer is not optimized for the uninterrupted streaming of audio data. It has rapidly become established wisdom, therefore, that the optimal means of extracting audio data from a computer's USB port is to operate that port in what is called "asynchronous isochronous" mode. This lets the receiving device, such as a digital-to-analog converter (DAC), control the flow of data from the PC. In theory, asynchronous USB operation (not to be confused with the asynchronous sample-rate conversion used in some DACs) reduces jitter to unmeasurable levels, depending on the accuracy of the receiver's fixed-frequency oscillator, which is used to clock the data to the DAC. By contrast, in the alternative and almost ubiquitous USB operating mode, called "adaptive isochronous," while the sample rate of the output data, averaged over a longish period, will indeed be the specified 44.1 or 48kHz, there will be short-term fluctuations, or jitter, due to the oscillator having to change its frequency every millisecond to match the uncertain rate of data flow from the PC.