Tube Preamp Reviews

J. S. Bach's "Komm, Jesu, Komm" (track 12 of the Fine Arts CD, MD&GL 3322, available from Audio Advancements in New Jersey) features a panoramic soundstage with plenty of fine soprano voices. If there's anything amiss in the upper mids and lower treble of your system, the soprano upper registers will turn shrill and bright. Without the Cary, this range failed to sound entirely natural. Mind you, I'm pretty fussy—even a hint of brightness or edginess in this range is disturbing to me. The Theta DS Pro with either the Threshold FET-10/e line-level preamp or the Classée DR-6 preamp failed to render these soprano voices sufficiently natural to satisfy me. There was a residual glare and brightness here that interfered with my enjoyment of the music.

After I replaced these much more expensive preamps with the Cary, the sopranos began to soar sweetly and effortlessly and with such startling purity that even such a hard-boiled critic as yours truly could not repress tears of joy.

Max Bruch's Kol Nidrei (on Collected Works for Cello and Orchestra, ebs 6060) is well served by a spectacularly authentic cello timbre and image size. Textures are rich, despite an upfront perspective, and the cello breathes and blooms dynamically as the music ebbs and flows. BC—that is, Before Cary—the cello image was too sensational, overblown through the upper registers and meandering about the soundstage. The Cary took care of all that. The cello stayed in focus from top to bottom, and its image was also more solidly portrayed. The overall effect was less hi-fi–ish and more natural, to my ears much more satisfying as a microcosm of a concert-hall experience. Compared with the Threshold FET-10/e, the highs were lacking in air and bass lines weren't as tight. But that was a small price to pay for the elimination of lower-treble and upper-midrange irritants: edginess and glare disappeared entirely.

Julianne Baird's image size (Greensleeves, Dorian DOR-90126) was never more convincing than with the Cary. I've heard this CD through my system on numerous occasions through all kinds of electronics, but the Cary succeeded in painting Ms. Baird's outlines in the acoustic of the Troy Savings Bank Music Hall with a greater sense of Gestalt than ever before. The resolution of hall reverb was simply exquisite, the sense of focus almost palpable. Here, as elsewhere, sibilants were perfectly controlled; something that no other preamp or processor could completely tame before.

Loud orchestral passages, or dynamic blasts, were reproduced with a greater sense of ease and less harshness. The ability of the Cary to swiftly expand from soft to loud without a sense of strain or impending doom eclipsed the line-stage capability of any of the solid-state preamps I had on hand. Ariel Ramirez's Misa Criolla (Philips 420 955-2) is not exactly a bombastic piece of music. It moves from one tender moment to another, but is punctuated by some awesome choral blasts. The Cary sailed through these passages with more impact than I had experienced before.

Solo flight
The Cary also spent some alone time in my system—without the Theta. I experimented with the two-year-old Sony CDP-705 ESD that I had been using to drive the Theta feeding the DR-8 amps directly as well as through the CAD-5500. This proved to be a very informative exercise.

The Sony, on its own without the Cary's or the Theta's support, turned in a disappointing sonic performance and really showed its age as a CD player. The soundstage was consistently less transparent. Veiling was endemic to the point of obscuring much hall information. The sense of space was dramatically diminished as the depth perspective shrank, image size collapsed, and instrumental outlines lost their tight focus. Low-level detail was more difficult to discern. The treble became gritty and grainy. Soprano upper registers were bright and edgy. Bass lines were not as well defined. You get the picture. The music suddenly became irritating, boring, and rather uninvolving.

Introducing the Cary (but not the Theta) into the signal path injected much needed vitality and clarity into the soundstage. The quality of the treble became cleaner and much smoother. Soundstage transparency increased to the point where it was much more lifelike. More spatial and low-level detail was evident. I'm not suggesting that the Cary restored the sound to its former glory during its Theta days. The Cary alone, without a top digital processor output, was incapable of producing the Theta's midrange textural smoothness or exquisite resolution of spatial nuances. The Theta is simply astonishing in its ability to infuse the mids with a lifelike vibrancy. It became apparent that the Cary needed the Theta and the Theta needed the Cary. In concert, the two evolved a synergistic relationship. The Theta operating in the digital domain and the Cary in the analog domain carried the sound-reproduction capability of my system to new heights.

The Cary as a line-level preamp
An alternate reality for the CAD-5500 is as a line-level preamp. Think of it as a preamp that happens to improve CD sound. Both the CD and Aux inputs follow the same signal path; that is, they are both "processed" and are therefore interchangeable. It would be possible to feed an RIAA-equalized phono input into Aux and either a CD player or an analog tape deck into the CD input.

Just how good is the Cary as a line-level preamp? I investigated this question by running the Threshold FET-10/e phono section directly into the Cary's Aux input, then comparing the sound to that of the complete FET-10/e with its own line-level module.

I should preface this comparison by stressing the fact that the Threshold is a Class A preamp costing far more than the Cary. The phono front end consisted of the Aura turntable fitted with a Graham Engineering Model 1.5 tonearm. The cartridge, a loaner courtesy of Bob Graham, was the fabulous Koetsu Rosewood Pro IV.

Both the Cary and the Threshold line-level module proved extremely enjoyable. There were, of course, differences, some being of the tube vs solid-state variety: Midrange textures through the Threshold were lighter and not as robust as those of the Cary—especially in the lower midrange. More detail was evident with the FET-10, accomplished naturally by a lower noise floor and not through an overly analytical presentation. The Cary's treble was softer, and bass lines were not as well delineated as those of the Threshold. The FET-10/e's treble was better extended and airier sounding. In general, there was less grundge through the upper midrange and lower treble with the FET-10 in the chain. The Threshold reproduced textures more purely with less overlying electronic haze than did the Cary. This was readily evident with soprano voices. Pilar Lorengar's upper registers, for example (The Magic Flute, LP, London OSA-1397), shone more pristinely, as if through a cleaner midrange window.

All together, an excellent report card for the Cary. As an analog CD processor in conjunction with a Class A digital processor, it clearly belongs in Class A. It is clearly an excellent line-level preamp. But for phono applications, I would only rank it toward the top of Stereophile's Class B.

Summary
As I see it, the Cary CAD-5500 represents an indispensable high-end tool; one that no serious audiophile can afford to be without. If you presently own a stock CD player, the Cary will significantly improve its sonics as follows. The grain, edginess, brightness, and shrillness of the lower treble will be greatly reduced. The soundstage transparency and spaciousness will increase. All that with almost no side effects. The extreme treble is slightly closed-in and lacking in air. The overall character of the treble is a bit soft, but not overly so, and the bass is a bit less well-defined than with a good solid-state design, but that's about it. And you'll end up with an excellent vacuum-tube line-level preamp to boot. Should your budget allow the purchase of an outboard digital processor in the future, the Cary will still bring out the best in whatever processor you buy.

If you already own a digital processor, say a Theta, wait till you hear what the Theta can do through the Cary! This is a synergistic combination that must be heard to be believed. The residual glare and treble edge that the Theta otherwise exhibits are completely eradicated. The treble is better integrated with the rest of the range, to the point that harmonic overtones are much more cohesive and lifelike. And the spatial resolution of the Theta is enhanced to the point of being almost holographic.

Part of the credit for what the Cary accomplishes must be due to its inherent excellence as a line-level preamp. The rest, in my opinion, is due to the effect of the RPC circuit. How else is one to explain the treble transformation of my Theta DS Pro? I didn't mention this before, but the Cary also cleaned up some treble gremlins in my Sony PCM-F1 A/D converter. My master tapes sounded cleaner and better-integrated through the treble. The LEDs on the Cary's front panel lit up like a Christmas tree, indicating significant RF energy in the signal path during even moderately loud passages containing treble energy.

I can't imagine listening to CDs again without the benefit of the Cary. I'm sure that the Cary and Theta will be wedlocked in my system for a long time to come. As Dennis Had puts it: Caution, this unit is habit-forming!