By ANTHONY H. CORDESMAN
Company Address: 5330 Derry Ave., Suite R, Agoura Hills, Cal. 91301; phone, 818/597-9195; fax, 818/597-1079.
Both the Theta Digital Data III CD transport (which can also be used as a laserdisc player) and DS Pro Generation V-a D/A converter are improved versions of components well known to many audiophiles. The new iteration of the DS Pro is the first D/A converter I've reviewed that offers both a separate computer and algorithm for digital processing and the option of an HDCD filter; this makes it possible to compare HDCD with Theta's fundamentally different type of digital processing. The Data HI, a far more advanced transport than the earlier Data II, utilizes Pioneer's top-of-the-line laserdisc mechanism, with separate loading drawers for CD and laserdisc. It now automatically plays both sides of a laserdisc and offers a wide range of control features for movie buffs who like to dissect films frame by frame. By itself, the Data III can play only the analog tracks on a laserdisc; to hear the digital sound-track, you need to add an external D/A converter.
The Data III transport, which sells for $4,500, has three digital audio outputs (RCA coaxial, BNC coaxial, and AES/EBU balanced), with the option of adding an AT&T ($300) or Theta's proprietary Laser Linque ($800) glass-optical output. There is also an RF output jack for AC-3, BNC and RCA composite-video out puts, and two S-video outputs. Loading time for CDs and laserdiscs is much faster than in previous Theta transports, and the ergonomics are very good. The front-panel controls are relatively simple, and the remote is reasonably easy to understand. (Any experienced Starship captain should be able to operate it after only a year of training at the Academy.) A switch turns off the panel display to avoid any interaction between the display circuitry and the audio and video signals; another switch can disable the video circuitry during CD playback. Both of these switches make slight, but noticeable, improvements in low-level detail and transparency and in the definition of depth and imaging.
In the Data III, Theta Digital has done a great deal more than simply adding digital outputs to a laserdisc player. One whole side of the interior is filled with five isolated, separately regulated power supplies for the video and audio sections. The digital audio output board contains a volt age-controlled crystal oscillator that is hand-calibrated, through the use of a high-resolution time-interval counter, to re duce jitter. All of the electrical digital outputs are pulse-transformer isolated and are driven by high-speed C-MOS logic gates. The Data III's video circuitry carefully isolates vulnerable video lines to ward off pollution from nearby dig ital audio signals, and all of the units are hand-tweaked to improve picture quality.
The result is a truly outstanding transport. The Data III offers far better video performance than its predecessor and equals that of any laserdisc player I have used. It provides excellent tracking, low noise playback, and fine resolution and color. I usually preferred the picture without the Data III's digital noise reduction, but this is true of such circuits in all of the laserdisc players I have used. Its sound was consistently better than that of laserdisc players that had only low-quality Toslink outputs, even when I used an Audio Alchemy or a Theta Digital jitter-reduction device. The Data III also produced cleaner sound than I have heard from stock laserdisc players that have coaxial digital outputs. The improvement showed up largely in low-level sonic detail, which affects depth, imaging, sweetness, and apparent dynamic range.
I also compared the Data III's performance in reproducing CDs with that of the Mark Levinson No. 31 and PS Audio Lambda transports and the Krell KPS-20i CD player used as a transport. The audible differences were slight and highly dependent on the D/A converter, cable, and interface I used. It seemed to me that each manufacturer had optimized its transport to sound best with its own D/A converter. But all four transports performed well with other brands of converters, particularly when I used a top-quality cable and the AES/EBU or AT&T interface. The Mark Levinson No. 31 did a slightly better job on CDs so badly made that any sane audiophile would discard them. But you'll seldom hear a musically meaningful difference between today's best transports, particularly with recent audiophile-quality CDs.
In short, I believe the Data III competes with the state of the art in CD transports. It may be the state of the art for those looking for the best possible sound from laserdiscs.
Theta Digital has made fewer improvements in its top-of-the-line DS Pro Generation V-a D/A converter. (I reviewed the previous version in the February 1995 issue.) The analog section now uses six hand-selected sets of eight matched transistors, which Theta feels will improve sweetness and imaging detail. The company has also eliminated the inductors in its output filters, in an effort to reduce sibilance, tighten the focus of the imaging, and improve tonal quality.
The most important change in the Generation V-a is the availability of an HDCD filter/decoder as an option. This option adds $459 to the price of the DS Pro Generation V-a D/A converter, which sells for $3,795 with un balanced connections and $5,600 with balanced ones; an AT&T optical in put costs an additional $300, and Theta's Laser Linque input is $800.
I auditioned two samples of the DS Pro Generation V-a, one with HDCD and one without, so I could analyze the value of the HDCD option. The unit without HDCD revealed a number of subtle but important improvements in sound quality. It was sweeter than its predecessor and more de tailed. The noise floor seemed slightly lower, which improved the apparent dynamic range and soundstage detail. The upper midrange was more harmonic and musically natural with strings and woodwinds. Brass had a more musical bite, with less trace of digital edge, and good recordings of cymbals had a more natural shimmer and decay.
The DS Pro Generation V-a was not quite up to the Mark Levinson No. 30.5 in its ability to resolve upper-midrange and treble detail or to extract very low-level musical information. Yet it was richer in the midrange than the 30.5 and had more powerful and dynamic bass. Its bass was excellent, surpassed only by that of the converters in the Krell KPS-20i player. The Generation V-a was also slightly more dynamic than either the Mark Levinson or the Krell. It seemed state of the art in terms of depth and front-to-back imaging. Overall dynamics and soundstage perspective were typical of what you might hear on the main floor of a concert hall, about one-third to halfway from the stage.
The HDCD filter, which automatically decodes HDCD discs, proved a mixed blessing. It did reveal that HDCD recordings are getting better: Reference Recordings' Leos Janacek (RR-65CD) and George Whitefield Chadwick (RR-64CD) discs, for example, are two of the finest recordings I have heard. But the HDCD setting forces you to use the digital filter in the HDCD chip and bypass the filtering system that is the heart and soul of the Generation V-a.
My listening panel and I mostly preferred to listen to HDCD recordings using the Generation V-a's native digital filtering rather than the HDCD option. Although the HDCD filter provided a bit more up per-octave detail, it was less musically natural and less warm; it spotlighted right-to-left imaging relative to depth. Blind listening tests with non-audiophiles produced roughly similar results. Opinions among my "guinea pigs" were divided, but most preferred the Theta filtering.
More broadly, I found no reason to prefer the sound of HDCD discs over others. Reference Recordings makes some of the world's best recorded CDs, but playing its HDCD recordings back through an HDCD decoder didn't yield sound better than that of well-made non-HDCD recordings played through conventional converters. I listened at length to Reference Recordings HDCD-encoded CDs and other audiophile CDs through the Theta DS Pro Generation V-a, with and without HDCD. Recent recordings from Chesky (Oregon's Beyond Words, JD130, and 0 Magnum Mysterium, CD83), Sheffield Labs ( The Art of Fuguing, 10047-2-G, and Earth Chants, 10049-2-F), and Telarc (Oscar Peterson's The More I See You, CD-83370, and Jim Hall's Concierto, CD-83365) did not have the same sound character as the Reference Recordings CDs but were equally musical. The differences among discs from these labels seemed to be more the result of production values and microphone choice and placement than of anything to do with HDCD. I also played good "extra-bit" recordings, including a Sony Classical Super Bit Mapped CD (two Mozart string quintets, SK-66259) and a Deutsche Grammophon Authentic Bit Imaging disc (Vivaldi's The Four Seasons, 43 9933). These recordings roughly equaled the HDCD recordings in most musically relevant aspects of sound quality. Consequently, I would buy the Generation V-a without the HDCD option and put that money toward something more useful. In the Generation V-a, HDCD not only doesn't gild the lily but tends to diminish its bloom.
The Data III is a tempting A/V crossover product. I occasionally use it in my A/V reference system, and I look forward to using it with AC-3 processors. I cannot, however, end this review without stressing the synergy between the Data III and DS Pro Generation V-a, using Theta Digital's Laser Linque glass-optical interface. The stereo sound from this combination is truly musically involving and offers an outstanding mix of musical nuances.
[ Orig. publ. in Audio magazine APRIL 1996]
Also see:
Theta DSPro Prime D/A Converter (Auricle) (Aug. 1992)
Theta Digital Casablanca surround preamp (Apr. 1997)
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