Digital Processor Reviews

A reader recently asked if I preferred listening to loudspeakers or to headphones. There is no easy answer: Although I do most of my music listening through speakers, about 10% of that listening, for various reasons, takes place in the privacy of my headphones. I have also found that, since I purchased the Audeze LCD-X headphones following my review of them last March, I now tend to watch movies on my MacBook Pro, with the soundtrack reproduced by these headphones plugged into an AudioQuest DragonFly or whatever D/A headphone amplifier has been passing through my test lab. So when Meridian's PR person, Sue Toscano, asked me last Christmas if I'd be interested in reviewing the English company's new Prime D/A headphone amplifier ($2000) with its optional Prime Power Supply ($1295), it took me less than a New York minute to say "Yes."

It's like hearing the name of an old friend and then seeing him, in your mind's eye, as he was when you were both much younger: Whenever talk turns to Boulder, Colorado–based PS Audio, I can't help picturing that company's Model IV preamplifier, of the early 1980s—most likely because that was the preamp I longed to own at the time. (Tragically, I couldn't afford to buy it, so I struggled on with my NAD 1020.)

$13,000! You could buy two Hyundai Excels for that kind of money. Or one 5-liter Ford Mustang. Or two-thirds of a Saab 900 Turbo. How could the purchase of this Accuphase two-box CD player be justified on any rational grounds? What if it did offer state-of-the-art sound quality? Would it really be 50 times better than a humble Magnavox? Would it even be 4.3 times better than the California Audio Labs Tempest II CD player? And would it approach the sound quality routinely offered from LP by the similarly priced Versa Dynamics 2.0 turntable?

No, the $399 price listed in the specification block isn't a misprint. And yes, the Audio Alchemy Digital Decoding Engine v1.0 is indeed a full-function outboard digital processor. And since this is the August issue, not April, you can stop worrying that this review is some kind of joke.

The $399 Digital Decoding Engine is for real.

Were it my place to hand out awards for "The Most Forthright People in Audio," Michael Grace of Grace Design would be at the top of the list. Years ago, after I'd given stellar recommendations of Grace's 901 and m902 headphone-amplifier-DAC-line-stage models, I asked Grace if I could audition his full-rack–size, more fully featured m904 Stereo Monitor Controller. He told me that he didn't think that was necessary, because the m904's sound was extremely similar to the sound of the smaller m902—it just had a different feature set, and he believed that the additional features were not things that Stereophile readers were likely to need. That is the only case I can recall of a manufacturer's declining an offer of additional coverage in Stereophile.

Back in the summer of 2009, USB-connected D/A processors that could operate at sample rates greater than 48kHz were rare. Ayre Acoustics had just released its groundbreaking QB-9, one of the first DACs to use Gordon Rankin's Streamlength code for Texas Instruments' TAS1020 USB 1.1 receiver chip. Streamlength allowed the chip to operate in the sonically beneficial asynchronous mode, where the PC sourcing the audio data is slaved to the DAC. But high-performance, USB-connected DACs like the Ayre were also relatively expensive back then, so in the January 2010 issue of Stereophile I reviewed a pair of soundcards from major computer manufacturer ASUS , the Xonar Essence ST and STX, which, at $200, offered a much more cost-effective means of playing hi-rez files on a PC.