Cary Audio Design CAD-300SEI integrated amplifier Art Dudley, May 2009
My first experience with a single-ended triode amp wasn't as good as my first ride in a convertible, my first trout caught on a dry fly, or my first kiss. But it was better than my first ride on a Ferris wheel, my first cigarette, my first day as a substitute teacher, and my first hernia repair. It didn't hurt, it didn't make me throw up, and it left me wanting more.
My first SET was a Cary Audio Design 300 SEI integrated amplifier, on loan for a magazine review in 1995 (footnote 1). Then as now, the Cary was an exceptionally nice-looking thing with a decent brace of user controls, three line-level inputs, and an output section capable of developing 10 or so class-A watts across a loudspeaker load of 8 ohms. More to the point, then as now, the Cary sounded wonderful: consistently sweet and substantial, but pleasantly soft, with an uncanny ability to pull solo voices forward of everything else in the mix. The latter is something I've come to associate with virtually all single-ended amplifiers.
The design brief was simple: The input signals for the left and right channels were applied to the two halves of a 6SN7 dual triode (a then-obscure tube that Cary Audio helped popularize), and then to another pair of 6SN7sone per channelconfigured as constant-current driver stages. Each of those was capacitively coupled to the grid of a single 300B directly heated triode tube, whose plate was tied to the 400V rail through the primary of a custom-wound air-gap output transformer, the two secondaries of which were routed to a toggle switch for load selection. Power-supply regulation was all solid-stateincluding regulated DC for the 300B and 6SN7 filamentsand power smoothing was accomplished with a pair of channel-specific pi filters.
Although single-ended topology was still novel in 1995, it wasn't unheard of: Audio Note had already set tongues a-wagging with their original Ongaku integrated amp, and, thanks to Joe Roberts and his groundbreaking magazine, Sound Practices, SET amplifiers designed and built by Don Garber, J.C. Morrison, Gordon Rankin, Nori Komuro, George Wright, and various others were gaining in reputation. While those men all contributed to making the world safe for SETs, Cary's Dennis Had pioneered a different route: making SETs that were safe for the world, with traditional high-end parts and construction details, and with features and styling that the relatively hair-shirt SETs of the day didn't equal.
So it was with the Cary 300 SEI, introduced in 1994: Its more conservative origins could be seen in such details as the above-mentioned impedance switch, as well as its user-cordial balance control and a switchable headphone jack. On the other hand, the 300 SEI was hand-wired, point to point, and Cary offered oil-filled coupling capacitors as extra-cost options: Had knew how to make good-sounding amps, even as Cary's commercial success began to disqualify their products from serious consideration by the painfully hip.
During the second half of last year I spent a few months with a fresh sample of the Cary 300 SEI ($5500). While its circuit appears mostly unchanged (footnote 2), the new amp differed from my first review sample in some small but noteworthy ways: Its output tubes are now Chinese-made Carys (the originals were American-made Cetrons, now extinct and sorely missed); those oil caps are now standard equipment; its volume pot plays host to a remote-controlled motor; its Edison Price Music Posts have been replaced by loudspeaker terminals of a commoner sort; and its faceplate now wears a brushed-aluminum finish. (The option of a gold-plated faceplatea crazily beautiful thingappears to have been discontinued.)
With its stock tubes, the 300 SEI delivered very much the same performance I remember from its ancestor. Compared with my combination of Shindo Masseto preamp ($11,500) and Corton-Charlemagne amps ($10,000/pair), the Cary integrated was less stirring and a bit lacking in detailthose sonic pores that connote texture in realistically recorded acoustic music were somewhat smoothed over and filled inyet it retained all of the characteristic strengths that have kept me in low-power heaven for 15 years. Lee Feldman's voice on "Give Me my Money" and "Me and My Sara Remaining," from his enduringly wonderful I've Forgotten Everything (CD, Urban Myth UM-114-2), was right there, whole and human and physically distinct from all of the other sounds in the mix. The same held for the lovely mono recording of "Toi, le couer de la rose," from Ravel's L'enfant et les sortilèges, that appears on a collection of the performances of the late soprano Bidú Sayão (CD, Sony Classical MHK 62355).
More important, the 300 SEI excelled at the SET strength that so often goes unremarked: It played melodies with organic, unmechanical, sinewy rightness and flow. The Cary caressed the strangely beautiful melody of the third movement of Brahms's String Quartet 1 in a recording by the Juilliard Quartet (CD, Sony S2K 66285)there are some sneaky dynamic shadings in that one, too, and some unexpected pizzicato notes from the cello, all of which came across similarly welland brought an extra dose of drama to even very compressed rock drumming, such as Mitch Mitchell's fills on Jimi Hendrix's Axis: Bold as Love (CD, MCA MCAD-10894). Throughout its time here, with music of almost every sort, the 300 SEI was always at least pleasant and inviting, often compelling and musically insightfuland never fatiguing or uninteresting.
While the Cary was here, I also tried fitting it with a couple of aftermarket output tubes, and in both cases was surprised that the differences weren't more pronounced. (That either says something good about the stock Cary tubes or something bad about my hearing.) The enduringly popular Western Electric 300B ($400 each, $900 per matched pair) made the biggest difference, giving a bit more texture. The WE tubes also sounded timbrally richer, but the individual listener's tastesor systemwill determine whether or not that's a good thing. Bright CDs benefited, including the Sony Brahms disc, while retaining sonic bounce and musical momentum and flow. Dull CDs, however, such as the Vienna Piano Trio's well-chosen collection of fin de siècle works by Zemlinksy, Schoenberg, and Mahler (CD, MDG Gold 342 1354-2), were tough nuts to crack, and left me a bit frustrated: At times it was too much of a challenge for me to extract from the thick sound the meaning and excitement I craved.
My experience with the 300B tube from Euro Audio Team ($1195/matched pair) was more frustrating. Apart from very slight increases in bass and treble extension, I was hard-pressed to hear any difference at all between the EATs and the stock units. (Note, however, that differences in frequency extension can be limited by output-transformer design, so don't write off the EATs based on this one sampling. They may be capable of much more with a different SET.) Timbrally, I'm certain that I could not distinguish the EATs from the stock tubes in a blind test.
In any event, the Cary 300 SEI remains an easy recommendation in every sense of the word: non-demanding, reliable, and consistently pleasant to listen to, given the right loudspeakers and room size. At $5500a little over $2000 more than he amp sold for 15 years agothe Cary remains an acceptable value for the money. What a pleasure to see a consumer-electronics manufacturer keep the same good product in its lineup for more than six months.Art Dudley
Footnote 1: The Cary 300 SEI was originally reviewed in Stereophile by Robert Harley in September 1995 (Vol.18 No.9), and by Jonathan Scull in December 2000 (Vol.23 No.12).Ed.
Footnote 2: The new sample was an auto-bias design, with a single top-mounted adjustment pot. My 1995 sample had an adjustment pot, toobut I'm not certain if that amp was an auto-bias or a fixed-bias design. (I'm tempted to say it was the latter.)Art Dudley