We are now well past the era in which every review of digital playback equipment had to begin with an apology for the medium. CD replay performance may, in fact, now be bumping up against a glass ceiling. But that doesn't discourage high-end audio manufacturers from trying to advance the art, and tempt audiophiles (at least those among us who are not hopeless digiphobes) out of our minds.
It's conventional wisdom among audiophiles: Small, high-end audio companies build high-quality products in small numbers. Products which are often expensive. But not always. Big mass-market companies build cookie-cutter products in big numbers. They're usually cheap. But not always.
If there is a component category that causes the "objectivists" in the audio community to splutter uncontrollably over their cups of herbal tea, it is the high-end CD transport. For in their "bits is bits" world, all a transport is required to do is recover the digital data from a disc—much like a grown-up cousin of your computer's $25 floppy-disk drive. The thought of paying up to $10,000 for something so humble—and, in their eyes, unnecessary—typifies what these blinkered folks regard as the insanity of the High End.
I have always been a dyed-in-the-wool vinyl fan, committed to the superiority of analog over current 44kHz/16-bit CD technology. Nevertheless, I have been surprised at how greatly the sound of CD has improved over the past 10 years. By 1994, digital had gotten much closer to analog than I had ever expected, which was a good thing, as 1994 also saw the disappearance of the LP as a medium for obtaining new releases of mainstream recordings. But over the last two years, I've noticed some interesting phenomena: More turntables, tonearms, and cartridges started to become available, at least in the high-end arena. Audiophiles and, to a lesser extent, segments of the general music-loving public, began clamoring for new vinyl releases. Specialty labels, such as Classic Records and Acoustic Sounds, started to reissue premium vinyl releases of classical, jazz, and pop classics at reasonable prices. And major labels again began to offer vinyl versions of major pop releases.
All the action in digital playback for the past seven years has taken place in separate transports and digital processors. Nearly all high-end manufacturers have focused their skills on perfecting the individual elements of the digital playback chain—transports and processors—rather than on designing integrated CD players.
Walking through the circus that was WCES '95 was like undergoing total neural-synaptic overload. I felt hard-pressed to just keep my head above water separating good sound from bad. Trying to piece together a coherent picture of the show, I jotted down the components in the best systems that I'd heard, and a few items popped up with astonishing regularity. One of these was Audio Research's single-chassis CD player, the CD-1.
Fantasy review time. I first heard about the C.E.C. TL 0 in the May '94 Stereophile (Vol.17 No.5), in Audio Mogul Richard Schram's Manufacturer's Comment to my review of the C.E.C. TL 1. I wasn't sure if he was kidding when he threatened the world with a cost-no-object $17,500 CD transport. Just what we all need!
The Krell KPS-20i (KPS stands for "Krell Playback System") is essentially a CD transport and digital processor in one chassis. What make the KPS-20i different from a CD player are the unit's five digital inputs, which allow the KPS-20i to function as a digital/analog converter for external digital sources.
It seems to me that it should be possible to make a perfectly jitter-free CD transport without resorting to elaborate, expensive mechanical structures. This idealized transport would ignore all mechanical considerations of disc playbackvibration damping and isolation, for exampleand simply put a jitter-free electrical driver at the transport output. If such a circuit could be made, it wouldn't care about how bad the signal recovered from the disc was (provided the recovered data were error-free). The circuit would just output a perfect, jitter-free S/PDIF signal. The result would be the sound quality of the $8500 Mark Levinson No.31 Reference CD transport in $200 machines. Such a scheme would provide an electrical solution to what has been considered largely a mechanical problem.
But back in the real world there's no doubt that attention to mechanical aspects of transport design affects sound quality. Examples abound: listening to Nakamichi's 1000 CD transport with its Acoustic Isolation door open and closed; playing the Mark Levinson No.31 with the top open; and putting any transport on isolation platforms or feet are only a few of the dozens of experiences I have had that suggest that mechanical design is of utmost importance.
So many things in this world are designed for convenience, not for excellence. That's all right if you have a choice, but it becomes a problem when products designed for convenience become universal standards and are thus foisted on everyoneincluding enthusiasts, who must then live with a product aimed at the lowest common denominator.
The digital interface between CD transports and digital processors is a perfect example of this dilemma. The Sony/Philips Digital Interface Format (S/PDIF) standard was designed so that connecting two digital products required only one cable. This single cable carries left and right audio channels as well as the timing clock essential to making the system work.
I find it astonishing that two products built on completely opposing engineering principles can both have musical merit. Design goals exalted by one company are considered anathema by another, yet both components produce superb sonic results.
At a "Meet the Designers" panel discussion at the 1992 Los Angeles Stereophile High-End Hi-Fi Show, I asked a group of successful digital designers (footnote 1) each to state how much of a digital front end's sound quality they believed was due to the transport, digital processor, and interface between the two. There was virtual unanimity: Nearly everyone agreed that a digital processor accounts for about 50% of a digital source's sound quality, the transport 30%, and interface 20%.
I think I've finally figured out the secret of Stereophile's success. You, cherished reader, don't read this mag because it's chock full o' reviews of tantalizing audio gear (even though it is). And you don't read this mag because JA and RL strive so hard to keep the literary quotient as hi as the fi (even though they do). And I know you don't read this mag cuz trusting yer own sensory input is a mighty scary proposition indeed so you look to Stereophile as to a Holy Bible that eases your Earthly burden by telling you, Ah say Ah say TAILING YEW what to buy (do you?).