Tube Power Amp Reviews

It says something for the state of technology that, after a quarter of a century, there still is no authoritative explanation for why so many high-end audiophiles prefer tubes. Tubes not only refuse to die, they seem to be coming back. The number of US and British firms making high-end tube equipment is growing steadily, and an increasing number of comparatively low-priced units are becoming available. There is a large market in renovated or used tube equipment—I must confess to owning a converted McIntosh MR-71 tuner—and there are even some indications that tube manufacturers are improving their reliability, although getting good tubes remains a problem.

Some audio products deliver truly superb sound of a kind that really makes all the frustrations of building a high-end system worthwhile; they also require exceptional attention and care. The Counterpoint SA-4 is a case in point. With the right speakers, it competes for the title of "Most Transparent Amplifier Available at Any Price." On the other hand, this amplifier steadily loses output power as speaker impedance drops; it must be carefully matched to the right speaker. Then, and only then, can it produce one of the finest musical experiences available.

Doshi Audio first crossed my radar at the 2010 Rocky Mountain Audio Fest, where I wrote that the sound of the company's tubed monoblocks and preamp, connected to Wilson Audio Sasha loudspeakers via Transparent XL cables, "excelled in midrange strength as the system threw an exciting soundstage." After auditions of Doshi-Wilson pairings at many subsequent shows had convinced me that Doshi's products could truly sing, I contacted company owner and product designer Nishith "Nick" Doshi to inquire about reviewing one of his amps.

Most of us have at least some taste for gear that jumps out—for audio components whose sonic and musical distinctions are easy to hear from the start. In audio, unlike in the art of music itself, there's nothing wrong with being obvious.

It is not at all unusual these days to find manufacturers producing "matched" speakers and amplifiers that are designed specifically for one another. But it is very unusual to find this being done by an amplifier manufacturer who doesn't make loudspeakers. The Futterman H3-A is one of these rarities—an amplifier designed primarily to complement one of the best, and one of the hardest-to-drive loudspeakers on the market: the KLH Model Nine.

I will never forget.

In 1988 I had my first experience with Western Electric 300B tubes. It took place on a quiet, streetlights-and-snow night at my friend Ryoichi's apartment on Riverside Drive, in Manhattan.

I had never heard of the late Japanese amplifier designer Ken Shindo, of Shindo Laboratory. But that evening, Ryo's audio system was all Shindo: a hammertone gray Shindo-restored, grease-bearing Garrard 301 turntable sitting on a Shindo plinth of glossy wood, with a Shindo-modified Ortofon tonearm and SPU cartridge, a Shindo moving-coil step-up transformer, and a Shindo preamplifier with a moving-magnet phono stage.

At the end of Gramophone Dreams #46, I was lost in the pristine beauty of Decware's 25th Anniversary Zen Triode amplifier driving the DeVore Fidelity Orangutan O/93 speakers. That was an extremely enjoyable system, and I was hoping to keep it intact for another month. My plan was simply to morph into my long-postponed opus on tube rolling using the Zen Triode as well as Ampsandsound's Bigger Ben headphone and loudspeaker amp. Both are single-ended triode, no-feedback designs and therefore perfectly suited for tube-swapping comparisons.