Hi-Rez Disc Player/Transport Reviews

Recently, we've seen the digital "horsepower" race accelerate with the arrival of digital sources and devices with 24-bit and 96kHz sampling capability. Much of this has been spurred by the 24/96 labels emblazoned on the newer DVD players—and, within the purer confines of the audio community, by high-end DACs with this same ability. Indeed, it's possible that the dCS Elgar DAC, near and dear to John Atkinson's heart and a perennial Class A selection in Stereophile's "Recommended Components," performs so well with standard 16-bit/44.1kHz sources because its wider digital bandwidth permits greater linearity within the more restricted range of regular CDs.

Other elegant and expensive DACs with overachieving specs are being offered by the elite of the audio world. Like the dCS Elgar, they sport the fancy pricetags that permit no-holds-barred engineering. Can their blandishments be realized without mortgaging your home? To consider this prospect, I auditioned three interesting new products that will fit into many more budgets: the Arcam Alpha 9 CD player, the California Audio Labs CL-20 DVD-Video player, and the MSB LinkDAC D/A processor.

California Audio Labs CL-20 DVD/CD player: $2495
As soon as I saw the prototype of this DVD/CD player—the most expensive product yet from California Audio Labs and the first to be released since their merger with GO-Video—at the January 1998 CES, I pestered California Audio Labs to send me one. Having just come from tantalizing demos of Classic Records' DVD-based audio discs, I was rabid to get my hands on a player, and the CL-20 looked like a great all-in-one product.

The CAL CL-20 is a substantial and hefty package based on a Panasonic DVD mechanism, but developed by a well-respected audio specialist firm. Inside, a substantial copper subchassis isolates the signal-processing circuits from the drive mechanism, itself floated on a vibration-damping suspension. I was struck by the spacious layout, the multiple regulated supplies, and the use of no fewer than four 1F (!) capacitors to stiffen the power supply for the dual Burr-Brown PCM1702 DACs, the way similar big caps do in automobile sound systems. (Hey, CAL—with the dual PCM1702s, why no balanced analog outputs?)

In addition to the dual analog coax outputs driven by plain-vanilla TL071 op-amps, the CL-20 has coax and AES/EBU digital outputs with 24/96 capability. These are supposedly limited to 48kHz sampling rates as the units come from the factory, because the DVD licensing agreement requires that the digital datastream be downsampled, encoded, muted, or otherwise mutilated unless the software copyright owner agrees otherwise. CAL's manual promises a simple activation with a key sequence from the remote control, but my review sample already had the 96kHz output enabled. [The permission to allow a 96kHz, 24-bit data output is actually carried on the DVD.—Ed.]

At a price of $2495, the CL-20 sits above mass-market DVD players, but it might not be overpriced if its audio performance can justify it. (Video/cinema is merely entertainment for me; good music speaks to my soul. And, yes, I'm ducking. Hey, if you want a different perspective, read Stereophile Guide to Home Theater!)

Sound quality
First, let's put aside the patently unfair advantages of the 24/96 DVD-format audio discs from Classic Records and Chesky and consider the CL-20 as just a CD player. As such, it is as excellent a player as one would expect from its heritage. Although there are no vacuum tubes inside, the CL-20 had the rich midrange and delicate HF that one often associates with good tube equipment. Voices, such as Barbara Hendricks' in the final movement of Salonen's Mahler 4, were accurately and graciously depicted. The larger orchestral ensemble was projected from a wide and deep space, but retained excellent detail and resolution. The Pink Floyd "Another Brick in the Wall" chorus was immediate and, in a startling effect, came from a greater height than the instruments! Bass extension, grip, and weight were more than adequate. I found that, despite having more than a handful of quality CD players on hand, the CL-20's tray was always the first to be filled when I wanted to listen to music.

The CL-20 sounded, in fact, very much like the Sonic Frontiers SFCD-1, but yielded to the senior player in soundstage depth; Sonic Frontiers is still the champ there. On the other hand, the CL-20 was significantly more potent on the bottom end than the SF, even though it did not approach the impact of Arcam's Alpha 9. Given the particular system context, however, the CL-20 seemed to provide the best balance of performance parameters of the three standalone players.

Feeding the digital output of the CL-20 to the Elgar DAC (with S/PDIF or AES/EBU link) and sticking with standard 16/44.1 CDs gave me another increment in performance: the individuation of musical voices and their relationships to the spaces around them. I could A/B the output from the Elgar with the analog output of the CL-20 and hear no differences in frequency balance or specific detail, but I was consistently impressed with how, with the Elgar, the voices seemed to be completely divorced from the speakers.

With the 24/96 DVDs from Classic and Chesky, there really is no useful comparison with standard "Red Book" CD players. The CL-20 playing 24/96 discs was unfairly superior to the other players (and itself) with matched 16/44.1 CDs. 24/96 discs seem to excel in the resolution of ambience and space. On the title track of a new DVD, Gee, Baby, Ain't I Good to You (Jimmy Rushing All Stars, Classic DAD 1005), the party atmosphere is natural and enveloping, but the sound of the band, particularly of Buck Clayton's muted trumpet, is startlingly present. Earlier I had auditioned some 24/96 DVDs on a borrowed Panasonic A310 and found that they offered greater space around individual instrumental voices and presented those voices with greater definition. (My best A/B was of John Lee Hooker's Mr. Lucky, Charisma 91724-2 and Classic DAD 1007.)

Unfortunately, the Pioneer A310 DVD player, even with its 24/96 DACs, had a lean tonal balance and was seriously deficient in soundstage. The CL-20, with its 20/96 DACs, had no such faults—and the strengths of the new medium were even more apparent. This, of course, should not be a surprise when you consider all the bells and whistles stuffed into the Pioneer while keeping the price to a fraction of the CL-20's. Clearly, CAL has chosen to invest in optimizing basic audio performance. I was thus hard-pressed to detect any difference at all between the 20-bit analog outputs of the CL-20 and those of the 24-bit Elgar on these same 24/96 DVDs! Hours of listening and comparisons revealed only one consistent distinction: The CL-20 had an extremely slight warming of the lower midrange. This added a little weight to the voices of Rebecca Pidgeon and Livingston Taylor on Chesky's 24/96 sampler (Chesky CHDVD171), but it was inconsequential on the rest of the discs I tried.

Conclusions
All three of these devices are excellent performers and excellent values. I found it fascinating that the Alpha 9 (a 24/96-capable player restricted to using 16/44.1 source material) and the CAL CL-20 (a 20/96 player capable of playing CDs and 24/96 DVD audio discs) were each capable of near-state-of-the-art performance. The 20-bit limitation of the CL-20 did not seem to be of great significance, and did not keep it from nearly equaling the Elgar's sound with 24/96 discs.

This leaves us with a dilemma: Is the word length or the sampling rate the more important parameter?

I believe that the higher sampling rate of the 24/96 discs underlies the "air" in the high frequencies, and the superb delineation of voices in real space, that are characteristic of DVD audio discs with various combinations and permutations of player and DAC. This was apparent on all the players, including the lowly Pioneer 310. In addition, playback at 24 bits via the Elgar was generally indistinguishable from playback at 20 bits directly from the CL-20, and both were substantially better than that from the nominal 24/96 Pioneer. The S/N and dynamic range of the extra 4 bits that the Pioneer and the Elgar were supposed to be giving me were not realized through the analog portions of my system. After all, 24 bits of resolution implies a potential dynamic range of 144dB. If you assume that the music uses all 24 bits, accurate reproduction demands that the electronics have a signal/noise ratio of at least 144dB, and that the speakers have a similarly wide linear dynamic range. Not bloody likely.

On the other hand, 96kHz sampling permits truly extended high-frequency response and the implementation of more gentle and distant anti-aliasing filters, but I can't say which of these is the more significant.

On standard "Red Book" CDs, with their limits of 16 bits and 44.1kHz sampling, all the combinations and permutations of player and DAC under test sounded pretty good...Moving up to the Alpha 9, the CL-20, and the Elgar, my preferences seem to follow the hierarchy of pricing more faithfully than with 24/96 discs. I believe this is simply the result of more dollars buying engineering of lower noise and distortion in the digital and analog portions of the machinery.

Thus, disregarding entirely its functions as a digital video player, the CL-20's price is amply justified by its audio performance alone. The CL-20 quickly became my preferred CD/DVD player for its superb tonal balance, transparency, and imaging. With the 24/96 discs piped through its 20-bit/96kHz DACs, the CL-20 was devastating: It made more than one analog addict believe that he had heard the future and that it is, indeed, digital.