Theta Jade CD transport

Many pundits in our industry say that CD is under threat from Super Audio CD, DVD-Audio, and dual-layer CD/DVD technologies. Conflicting stories abound, and even though I'm supposed to be well-informed, I've found some of them hard to sort out! For example, Michael Fremer, concluding a fine review of the $7500 Bow Technologies ZZ-Eight integrated CD player in August, compared its notable 16-bit/44.1kHz achievement with a DVD-based disc originally mastered at 24/96kHz and replayed on an inexpensive DVD player. He found the Bow wanting in some respects. What is the world coming to?

Writing in the February 1998 Hi-Fi News & Record Review, I compared the sound of the dCS Elgar decoder in 16/44.1 and 24/96 formats and found that the higher-resolution format had the potential to "improve" the sound of this decoder by 30–40%—in context, an amazing vindication of the real virtue of higher mastering standards.

Likewise, when that pesky subaudiophile DVD player noted above is used for standard CD replay, its performance falls to what you might expect for that kind of money, and would certainly be placed below Stereophile's usual standards for a "hi-fi" recommendation. Yet changing to the higher-resolution DVD-Audio format kicks the sound quality of such a player cleanly into the audiophile middle ground.

I've two observations to make. One, when it does get sorted out, the new high-resolution media will greatly improve the sound of moderate-cost equipment. Two, just imagine how good it's going to get with top-class, audiophile-directed designs. Once everyone decides what they're going to do—SACD, DVD-Audio, or possibly both—and in what format then designers can commence player design. Till then, confusion reigns.

So what about good ol' CD? Well, generally, it works pretty well for now. Just because there's a new set of possible formats and media doesn't mean CD's dead. Far from it. Designers continue to innovate and improve, and billions of CDs reside in people's collections. Moreover, tens of thousands of transports and decoders are susceptible to worthwhile improvement by judicious upgrading.

Theta's Jade CD transport costs $2495, depending on whether the AT&T optical output option is included. Specifically designed to get the most from the established format—it won't play anything but Red Book 16-bit/44.1kHz CDs—the Jade can be partnered with a range of decoders and digital audio–equipped components, CDR, processors, and the like. (If you want to go all the way, Theta offers, at significantly higher cost, a DVD- and CD-compatible transport.)

Targeted at the discerning customer, the Jade is built to very high standards. The handsome, full-width case and heavy, finely sculpted faceplate are made entirely of aluminum alloy. The remote control is large and full-featured. The ultraneat front-panel buttons comprise power-on/standby (the main power switch is on the back panel next to the IEC AC socket), plus Display, Repeat, Time, Play, Pause, Stop, and drawer Open/Close. Fast-forward and -reverse are engaged when the track-skip buttons are held down rather than momentarily pushed. The loading drawer is centrally placed, sensibly positioned below the display.

On first turn-on the display illuminates briefly and the player enters standby. The Display button powers down the display to reduce jitter. (The display temporarily brightens when receiving commands or when in Pause.) The Time button gives access to total, elapsed, and remaining playing time, the latter both for an individual track and for the entire disc. Edit sequences can also be programmed.

On its back, the transport sports coaxial (phono), coaxial (BNC), and balanced AES/EBU (XLR) data outputs, with an optional ST-optical output available.

Technology
The Jade's open chassis is based on four subassemblies. Beginning with the supply input filter, the power-supply board consists of six integrally mounted power transformers with local fast reservoirs and some preregulation. The multiple transformers allow easy separation of circuit blocks to reduce co- interference to levels well below that possible with the more common technique of using multiple regulators and fewer transformers. Near the front is a Pioneer "Stable Platter" transport mechanism—CDs need to be inserted label-side down. The transport proper is nicely decoupled on a nonresonant polymer suspension. The associated Pioneer transport control board is out of sight, screened from stray electromagnetic interferences by an ungrounded, hence possibly decorative alloy cover.

The transport speed is controlled from the fourth assembly, the main source of the Jade's intelligence. Here a high-precision local crystal oscillator directly and cleanly gates the transport's digital output, whose raw digital interface code is cycled through a buffer memory. In theory, the newly gated output from this local store should be essentially free from the usual transport-related jitter artifacts.

This data-buffer technology, first seen in Theta's more costly Pearl transport, clearly distinguishes this part of the design from earlier Theta models such as the Data Basic II, which used a Philips transport and Philips-compatible RC5 control code. S/PDIF data signals are isolated and coupled via wideband pulse transformers.

Sound
The Jade stands on plain rubber feet, and benefited significantly from a proper audio table and, for the very best results, a dedicated AC supply. Even if they meet the EEC's new EMC legislation (and rightly so), there is still much more high-frequency "hash" introduced on the AC line by digital products than from analog amplification; separation of AC power lines continues to give significant rewards.

Experiments showed that the best sound depended on the careful choice of both the digital link and the connection mode, balanced or unbalanced. This can vary between decoders according to the quality of their input-stage design, and also to grounding considerations. If the inter-chassis grounding is favorable, the unbalanced mode may give the most precise effect, with the best "grip." But grounding problems can manifest as a trace of sonic roughness, this addressed by adopting the balanced mode. Typically delivering a slight loss of attack and "speed," the generally pleasing AT&T optical connection obliterates ground problems and rewards the user with a consistently sweet, reliable connection. You may want to check out this option on the Jade with the help of your dealer, who is often best placed to advise you on the particular complexities of your audio system.

Theta recommends a conditioning period after first installation. This proved worthwhile: I heard modest but important gains in transparency and treble resolution.

Once the Jade was nicely run in, the serious listening began. Initially I was struck by the transport's positive timing quality, an emerging Theta characteristic that is not associated with the Pioneer mechanism it uses. I had liked the Basic II for its strong rhythm and timing, an aspect that encourages good listener involvement. This was generally continued with the Jade, but there were some differences. With the present-day focus now firmly on jitter, and with some awareness of jitter's possible effects on sound quality, it was fascinating to hear that extra degree of purity and resolution brought about by the data-storage technology and its special, precisely timed gating of the signal just before the signal is sent to the decoder. The result was substantially closer to the superior quality heard with designs in which the decoder is used to synchronize a compatible transport. The Jade delivered much of this benefit without using a special decoder.

Defining the sound of a transport isn't as straightforward as it is, say, for a speaker. While a transport does have a significant and worthwhile effect on replay quality, this effect is generally pervasive; specific errors are hard to pinpoint.

You can certainly appreciate if things are done right in a test system. For example, the bass was really good—the Jade showed no curtailment, and remained powerful and open down to the deepest audible tones. The low frequencies were nicely integrated with the midrange, the latter well-balanced with negligible harshness, and the soundstage had a pleasing perspective. Sounding accomplished, without obvious exaggeration and free from grain or tizz, the Jade provided very clear portrayals of fast transients with nicely focused, all-of-a-piece timing.

Rhythmically, the Jade wasn't as upbeat as the CDM9-drive–equipped Basic II, but the oft-encountered, seriously downbeat character of lesser, Pioneer-equipped designs has been largely addressed in the Jade, and the music generally moved along at a respectable pace. With a fine decoder, the combined performance approached that of advanced players in the $6000–$8000 range. Even more significant, the Jade proved both satisfying and unfatiguing with longer-term listening. Ultimately, I preferred the unbalanced phono connection to the various decoders I tried.

Conclusions
The price of this finely crafted transport is pretty competitive, especially for the non-AT&T version. The Theta Jade didn't quite match the finger-snapping excitement of the older Basic II transport, but it rewarded me with a finer-textured soundstage with a greater sense of scale, space, and depth. There was no loss of focus.

I'm not unduly concerned by the modest error correction, as many older discs gave little trouble. Powering down the display was worthwhile sonically, and a good shelf or platform provides an additional gain in solidity.

With its high resolution of detail, firm bass, sparkling yet unforced treble, and neutral midrange tonality, this transport clearly constitutes a high-quality source for high-performance digital decoders. I can confidently recommend the Theta Jade.

COMPANY INFO
Theta Digital Corp.
5330 Derry Avenue, Suite R
Agoura Hills, CA 91301
(818) 597-9195
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