Tube Power Amp Reviews

Manley is not a new company; it's the last name of the president and chief designer of VTL, David Manley, whose Model 300 has been my reference standard power amp for the past two years. In fact, Manley is not even a new brand name; it's the name of VTL's "deluxe" line of electronics, built (ostensibly) to industrial standards of ruggedness and reliability.

It's customary to think of "the tube sound" as being warm, rich, weak through the deep bass, fat through the midbass, forward through the midrange, bright through the middle highs, and soft at the extreme top, with superb rendition of depth and spaciousness. The "solid-state sound," by contrast, is generally thought to be cool, detailed, and pristine, with powerful deep bass, controlled midbass, rather reticent (laid-back) midrange and mid-highs, and a somewhat crisp high end, with variable (roulette-style) reproduction of depth and spatiality.

Leaving aside for a moment the fact that the Wavac SH-833 costs $350,000/pair—

We have to talk. Are you sitting comfortably? Is the reading light okay? Have a little something to drink at hand? (Audio is thirsty business.) The audio world is abuzz over the reintroduction of the single-ended triode amplifier. This is the first of three reviews of such amplifiers I'll be bringing you, along with two speaker systems with which to play them.

Brian Tucker, the US Quad importer, introduced me to the Woodside MA50 tube amplifiers and their manufacturer, John Widgery, during the 1992 Summer CES. Tucker's combination of Woodside MA50 tube amplifiers and Quad">http://www.stereophile.com/floorloudspeakers/416">Quad ESL-63 USA Monitors sounded unusually neutral, dynamic, and detailed. This was good news; back in 1987, Dick Olsher (Vol.10 No.6, pp.104–5) was unable to recommend an earlier Woodside-manufactured amplifier, the Radford STA 25 Renaissance. Brian mentioned that the MA50's design is a much-improved version of that earlier Radford model. Time for another review.

My stepfather wore only second-hand clothes as a child and never understood why anyone would deliberately wash the color out of his new dungarees. By the same token, the senior members of our hobby, many of whom recall with fondness the transistor's advent, don't understand why anyone would now wish to throw away their newfound power. Some people deserve to be blessed for their point of view, even as the world moves away from it.

Designers of hybrid amplifiers can use solid-state devices in an amp's input stage and tubes in its driver and output stages, as Music Reference's Roger Modjeski did in his RM-200 Mk.II—or they can use tubes in the input and transistors in the output, as Ypsilon Electronics' Demetris Baklavas prefers.

The advantage of solid-state at the input stage can be lower noise. In the RM-200 Mk.II's fully balanced design, carefully matched input devices result in high common-mode rejection and low-noise operation close to the levels achieved with the best input transformers. The RM-200 Mk.II's signal/noise ratio measured a healthy 95.4dB.

Like many other industries, audio has its power couples: behind-the-scenes movers-and-shakers who shape the trajectory of the industry and who also happen to be, well, together. Angela Cardas and Josh Meredith of Cardas Audio come to mind, as do Dave and Carol Clark of Positive Feedback, Eli and Ofra Gershman of Gershman Acoustics, Luke Manley and Bea Lam of VTL, Carl and Marilyn Marchisotto of Nola Speakers, Edwin and Gabi van der Kley-Rynveld of Siltech and Crystal Cable. George and Carolyn Counnas of Zesto Audio are a hi-fi power couple I'm especially fond of; I'm always happy to see them at shows, catch up with them on the phone, or exchange emails with them. Their sweet demeanor and good vibrations always lift my spirits.

George designs Zesto's preamplifiers, power amplifiers, phono stages, and step-up transformers, while Carolyn, a talented fine-art painter, gives Zesto's products their unique organic curves...