The Cary CAD 805B Triode Amplifier - IS THIS TRIODE HEAVEN OR WHAT?
The Absolute Sound, June/July 1994, Vol. 19 Issue 96
by Andrew G. Benjamin
I WASN'T EXACTLY ELATED, just mildly interested, when I pondered suffering through another tube amplifier review (even though enticing rumors reached these quarters from the grapevine): The Cary 805B, it was suggested, is a hell of a beast – a gentle brute that caresses the listener and can launch him into auditory delirium. This amp, the rumor went, was meant to smoke the best from Audio Research, Carver, Conrad-Johnson, Esoteric, Jadis, Valve Amplification, and VTL/Manley. I yawned. Recalling Cary's earlier products (which were obviously aimed at the middle of the High End), I didn't know quite what to expect. What arrived, however, was surely not what I expected.
The 805B is a stunningly-crafted, champagne-gold and crinkle-black mono-block amplifier with glowing thermionic (vacuum) tubes lined up like proverbial warriors in ascending size. Three tubes in all, the last, the gargantuan "John Holmes" of triodes*, the 211B transmitting tube. Not a transistor in sight. Behind these tubes are two sealed, potted transformers (power and output), and four large power supply capacitors. The thick, curved, smoothly-milled, champagne-gold front panel sports a winking "magic eye" clipping indicator, similar to the Grundig radios from the Fifties. In the rear, Cary installed the high-integrity OFC Edison Price Music Post speaker terminals (three pairs for the four, eight, and 16-ohm output taps from the transformer's secondary windings). One MIT film cap in the circuit and a few resistors. Simplicity incarnate. The amp is hard-wired, a la Jadis, no circuit board, and the power supply uses a choke to fight induced electrical noise. (Only a handful of makers employ a choke in the power supply. This technique was abandoned in the Fifties because of the expense.) All in all, the look is as classic and generous as it comes.
Innovative features include a standby switch which keeps the input and driver tube filaments heated, along with a unique, continuously-adjustable feedback control.
As for the sound: I'm caught with my pants down.** You see, at first listen, the CAD 805B doesn't sound much different from other edge-of-the-art tube designs. It just sounds more natural... in almost every way. Its sonics reminds me of the character of music itself: revelatory of emotion, intent, and detail, generously-scaled, emotionally exciting and, well, viscerally glorious. It recreates the event within the concert hall, a "virtual reality" of sorts, retrieving the acoustic breadth of the venue. More importantly, it reveals the harmonic wholeness, tonal depth and resonance, and textural complexity of instrument and voice; the macro and microdynamics of low-level sounds. In short, the 805B is so good at doing what amplifiers should have been doing all along that any superlatives I might throw at it will only make the reader the more skeptical.
In any case, I don't much care whether anyone believes me. As long as I own a pair of these, I've died and gone to heaven. If you are familiar with the sound of live music, can afford the 805B, and fail to audition it in your own system, you've made a grand miscalculation. You will never know the long-term satisfaction a truly great amplifier can provide.
I decided to shower praise early and not suppress my excitement so that you wouldn't just gloss over what follows. You see, the CAD 805B is a reference amplifier from both a musical and technical stand- point. (I don't mean to short-shrift the considerable cost for a pair of 805Bs. $7995 is a lot of dough for any amp, especially a 50-watt amp.)
I have always had an interest in Class A and triode amplifiers, finding them relatively successful as reproducers, though again, the virtues inherent in either Class A or triode operation do not in and of themselves guarantee sonic triumph. True Class A and pure triode amps are not powerful enough to drive most American speakers. For want of better terminology, many "triode" amplifiers are actually "pseudo" Class A and pentodes and tetrodes configured to operate in the triode mode. Most amplifiers that claim 100 to 500 watts output Class A do not actually deliver Class A wattage to full power. And pentode/tetrode tube types were specifically not designed for triode operation.
The Cary 805B is just the beginning in an industry-wide trend that will make waves. Other manufacturers are jumping on the bandwagon. Both solid-state, single-ended Class A designs and triode single-ended Class A amps are becoming available. They are bulky, heavy, hot running – and expensive. And they will be used in the very best audio systems.
Unlike what came before, the 805B can match modem (non-horn) speaker impedances and efficiencies, such as electrostatics, Magneplanar-type ribbons, and sealed dynamics with high-order crossovers. This amp can provide reasonable power output into difficult loads in excess of its published specifications. Even with the demanding, complex-impedance of the Martin-Logan CLS-IIz, the amp proved substantially competent.
These are physically large amplifiers. They are low powered in the absolute sense. However, not in the relative sense. I compared the apparent loudness levels and dynamic shadings of the 805B against excellent, comparably priced solid-state monoblock amps with an over 350-watt-per-channel output: the Classé Seven Hundreds. The Carys sounded more powerful and provided a greater sense of solidity, dynamic ease, depth, and nuance. That the 805Bs were unperturbed when driving my Martin-Logans is firm evidence of the technical competence of its designers and the careful execution of its build. Only at the highest crescendos did I sense moderate compression. And I could be wrong about that since the amp's clipping characteristics are mild and barely noticeable. (After all, 50 watts is a lot more power than most people might think!)
Now to the sound: With holographic spatial attributes, the soundscape opens onto a breathtaking panorama, filled with myriad details and textures of sonic delight. There is a solidity of image, a rightness of tonal color, and a sense of definition and substance that solid-state amps have never achieved and most contemporary tube amps only hint at. The midbass solidity that is indispensable for reproducing the resonance and foundation of grand-scale orchestral recordings is clearly in evidence. The gestalt of instruments are depicted with the requisite rounded body, lucidity, bloom, dynamics (perhaps not at the highest levels), microscopic nuance of details, cushions of air around each instrument, purity of tone, and clarity. The bass is solid, with utmost resolution – almost as controlled as the finest high-power transistor amps; but more believable, more "real." The highs? Glorious. Lucid, grain-free, naturally airy, but not as extended as, for instance, the Jadis Defy 7 or the Audio Research Classic series. The midrange? No excessive etching, brightness, texture, or glare, simply a proper proportion of musical detail containing fleshed-out timbres replete with a wealth of subtlety and refinement, otherwise repressed, subdued, and bleached by lesser amplifiers.
The 805B's harmonic truthfulness reminds one of the coherency of good electrostatics. Their harmonic verity allows entry to a sonic realm dose to the real. To achieve this performance, however, one must experiment with the 805B's output taps to optimize speaker coupling, and also adjust the feedback. One also has to install AC cables, interconnects, and speaker wires as good as the Purist Audio Colossus. (I found these to be about the best possible for the CADs. Perhaps they are also a good choice for other upscale systems.) The wrong cable can make the 805Bs sound like a Japanese receiver, so be warned!
I said the bass is remarkably forceful, honest, and controlled. Not "punchy," however. Just take Michael Jackson's Bad [Epic 40600] for a spin. The last cut, "Smooth Criminal," has stunning low-frequency beats. I'd never heard the heartbeat at the beginning as solidly stated. It is as if an additional half octave were added to the system. A cliché to be sure, but the heartbeat has power and drive it didn't have before, and I can hear the fundamentals pulsating with energy. The CLS-IIz is not considered a rock 'n roll speaker, yet, with the 805B, I was achieving bass of a quality I thought possible only with dynamic woofers, and without the "doubling" distortion of dynamic designs.
Lovely acoustic bass plucks are recorded on Rickie Lee Jones's Pop Pop [Geffen 24426]. The naturalness I hear is what one would expect in a good jazz club, albeit closely miked (and Prosonus's "No-Noise" processed). The recording sounds elegant. How the string bass is spiked to the stage can be discerned, not just the soundboard, or the way the strings buzz against the fingerboard. We "see" the instrument's physical form and hear its sound radiation pattern.
The 805B's midrange also possesses this coherency and substance. The reproduction is illuminated with the same unity and consistency heard in live sound. I suspect that the single-ended topology has much to do with this sonically unifying characteristic. I do not suggest that the 805B has no coloration. Full-bodied, they are decidedly tube-like in character – liquid, grain-free, smooth, and pure, but neither dark nor light, pale nor glaring. (All components have some sort of sonic "thumb- print.") The 805's sound is largely made up of the same fabric and material, matter, and medium of which music is perceived. What colorations exist tend to fall by the perceptual wayside when one hears the 805's spatial attributes, focus, and dimensionality. The wonderful, naturally-recorded Flojtespelar- dansen gar... [Proprius 7759] provides not just genuine, complete timbres on both female and male choirists, but a fully-realized acoustic venue with layers of depth, resonance, and air. So what, you say? Other amps do that! Well, not quite. I mentioned "coherency," which I define as the assembling of essential harmonic, imaging, and spatial characteristics into a whole that may just be greater than the sum of its parts. I speak of a greater articulation of believability. Not just definition or intelligibility as such, but a deeper conveying of the musical intent. If the 805B is optimized with your system, the effect is jaw-dropping.
With the Proprius disc, we hear the bell-like clarity of the accompanying instruments; long decays of ambience and hall-sound; nuanced hues encompassing the vocalists' polished and refined intonations. It's not that the 805B creates something that isn't there, but rather that the 805s recreate the performance as you've not heard it before. Less like reproduction, more like the real.
As said before by wiser men than me: God is in the subtleties. For music it is necessarily so. Loud and superficial is just that. Subtlety, however, encompasses a range of experiences more profound, lasting, exhilarating, elegant, and sensual. And this is where the CAD 805B makes a breakthrough in the sonic arts. In sum, the varied nuances they uncover in the music are not a trifling matter, but a grand opus.
I resent the cost. Damn, everything has become so expensive. These days I'm thinking of trading down my 1983 Chevy Caprice for something more modest. But I'd be willing to forego food and beverage for these amplifiers. I can see these in my system years from now because the design is not just classic and true, but will likely remain so. This kind of performance has staying power. And the build quality is something one can admire with confidence. Even at their price, the 805B cannot be considered a poor investment, but rather a longterm one which will bring joy into the audiophile's existence. The cost for this fine music reproducer is no more unreasonable than for a good music producer, a well-made musical instrument. In that context, then, the 805B is worth more than its measure in dollars.
I am left not uncritical, yet profoundly moved. I cannot, just yet, find much to fault in this less-than-perfect amplifier, I do hear many virtues to admire. To be sure, the 805B's mild colorations and not exactly high power output are something to admonish. However, neither is a shortcoming I could not live with. Besides, other highly touted amps have faults I know I cannot tolerate. If I could only win the Lotto!
– Andrew G. Benjamin
* He's not kidding.
** I hope he is kidding.
1 The former 805s were not. They clipped early, and the upper midrange had a subtle "fuzz" riding on top of the music. The 805Bs use new power and output transformers. The 805B is fundamentally different from the earlier 805.
2 The output from either a 50 or 200-watt amp will be the same, given the same input sensitivity end input voltage. Generally, music is listened to at between a fraction of a watt to about 10 watts, and 50 watts is ell most speakers will need. Anyhow, with the problems inherent in optimizing transformer technology, I feel a fine low-powered amp will beat a good high-power design any day. The same rules apply to output transistors. The rugged ones used in the higher-power designs are slow and therefore e low-powered solid-state amp – all else being equal -- will be better sounding than its high-powered counterpart.
My thanks to the Cable Company for their assistance in my struggle to find a cable which sounds best with these amplifiers. This company, by the way, is unique. I highly recommend their services. They will let you experiment and try any wire on the market and help recommend the right wire for your specific system. The Cable Company manages a database of customers'(and reviewers') experiences with wires, speakers, end electronics; compiles this data, and makes it available for its customers.