Reference

Although I still haven't been able to listen to the Cary Audio Design 805 single-ended tube monoblocks that Stereophile praised so highly a year ago (Vol.17 No.1, p.104), I've recently auditioned many other tubed single-ended designs. Undeniably, a good SE design has a distinctive quality of harmony and atmosphere in the midrange that reaches well beyond the average attainment of its solid-state brethren.

The Complete Guide to High-End Audio
by Robert Harley
450+xxiv pp., $29.95 softcover, $39.95 signed hardcover. Published by Acapella Publishing, P.O. Box 80805, Albuquerque, NM 87198-0805. Credit-card orders: (800) 848-5099.

Back in the spring of 1990, Stereophile introduced its first Test CD, featuring a mixture of test signals and musical tracks recorded by the magazine's editors and writers. Even as we were working on that first disc, however, we had plans to produce a second disc which would expand on the usefulness of the first and feature a more varied selection of music. The result was our Test CD 2, released in May 1992.

Nothing quite new is perfect. —Marcus Tullius Cicero, Brutus

High-end audiophiles are space freaks---we relish the warmth and spaciousness of a fine, old performing hall almost as much as we do the music recorded in it. But my attendance at a series of orchestral concerts held last summer brought home to me---as never before---the sad fact that our search for the ultimate soundstage is doomed to failure: we're trying to reproduce three-dimensional space from a two-dimensional system, and it simply can't be done.

On a number of occasions we have commented on the effects of an amplifier's output impedance on a system's performance. A high output impedance—such as is found in many tube amplifiers—will interact with the loudspeaker's impedance in a way which directly affects the combination's frequency response. The Cary CAD-805, for example, has a lower output impedance than most tube amplifiers, and should be less prone to such interaction. Some months back—before the CAD-805 arrived—I investigated this phenomenon in conjunction with measurements for a forthcoming review of the Melos 400 monoblock amplifier. Since the Melos 400 also had a relatively low output impedance for a tube amplifier (at 0.43 ohms at low and mid frequencies, rising to 1.2 ohms at 20kHz, from its 8 ohm tap), I took that opportunity to run some frequency-response measurements using an actual loudspeaker as the load for the amplifier.