Tube Power Amp Reviews

The only thing that excites me as much as finding an excitable new affordable component (which I define as below $1000, and the lower the better) is a new "trickle-down" design from a cutting-edge designer. Thankfully, such new "real-world" products are becoming more commonplace in the High End. The process begins when a talented high-end designer releases an expensive, cutting-edge product that is hailed by the audiophile press as a breakthrough, a new "reference."

Most reviewers look for a "hook" or angle of some kind when it comes time to write a review. After all, how many ways are there to get excited about audio equipment? Kathleen and I like to focus on the human side of the High End. So it was with some amusement that I watched the obstacles swirl around what I thought would be a fairly straightforward review of the Vacuum Tube Logic MB-1250 Wotan monoblock power amplifier. My thought was to return from single-ended to push-pull with a bang! I'll say...

It all began at the January 1996 WCES, where I found my shorts positively welded to the listening chair during a memorable musical blast at VTL. Luke Manley and his extreme audiophile wife Bea had a good thing going and they knew it. People were talking. "Did you hear those monster two-storey VTLs on the Alón Vs?"

Although I'll be spending most of my time at Stereophile reviewing affordable gear, I will from time to time examine so-called "trickle-down" designs from high-end designers who have made their mark in the upper-price echelons. More and more, such designers are taking what they've learned and applying it to less-expensive products in order to broaden their customer base. Cary Audio Design, for example, of single-ended triode fame, has entered the ring with the SLM-100 pentode monoblocks.

I've never written a love story before, but then, there's always a first time. This romance concerns the stunningly anthropomorhic Jadis Eurythmie II (mostly) horn speakers and the petite, jewel-like and vivacious Jadis SE300B amps—a 10W single-ended triode design with paralleled output tubes.

Kathleen and I, having flung ourselves into single-ended's embrace, have become, to some fashion, quite experienced. I've described the purity of presentation available with the Wavelength Audio Cardinal XS monoblocks when coupled with the Swiss-made Reference 3A Royal Master Controls in these pages (January '96). Using the Eurythmie speakers, which supplanted the 3As in our system, we've listened to Gordon Rankin's Wavelength Cardinal XS monos, the Kondo-san Audio Note Kasai parallel 300B stereo amplifier (next SE review to come), the ebullient and eager-to-please Cary 301SE 300B stereo unit, and the Jadis single-ended triodes, as well as our reference Jadis JA200s (yes, Jadis also does push-pull).

This should have been a recipe for disaster.

It's no secret. David Manley has not been big on single-ended amplifiers. Not enough muscle. You're better off with push-pull. Still, with a growing market for single-ended stuff, I'm sure Manley saw a need to do something. Of all tube designers, Manley has always been among the most prolific.

How important is the use of balanced circuit typology in the design of preamplifiers and power amplifiers? Ask the top audio designers (I didn't, but just play along, okay?) and you'll get a wide variety of opinions. Some reject the balanced approach outright, arguing that it represents a needless duplication of circuit components, and that better results can be achieved if the same attention and resources are devoted to perfecting a single-ended circuit. In his provocatively titled article "Balance: Benefit or Bluff?" (Stereophile, November 1994, p.77), Martin Colloms questioned the advantages of balanced designs, suggesting that while the results may be better in certain respects (eg, noise level), the reproduced sound may suffer in other, perhaps more important ways (eg, rhythm and dynamics).

I love being seduced. I'm shocked to learn that not everyone does. The very qualities in live music that excite and intoxicate me are denigrated by many audiophiles as "colorations." It would seem they prefer the lean, chilly sound that they've dubbed "accurate." While I concede that almost all of their preferred audio components have ever-more-extended high frequencies, I'm not certain that that's the same thing as having greater accuracy. It sounds to me—to use Stravinsky's description of electronic music—"spayed for overtone removal." The overtones that I miss are those stripped from the middle ranges—the ones the clinical crowd (footnote 1) disparagingly refers to as the "warmth" region.