Tube Power Amp Reviews

Nick Doshi is cautiously reserved when he talks about his amplifiers, preferring to let the products speak for themselves. At every show I've heard them at, from Chicago to DC to Munich, they have done exactly that: Every system I've heard featuring a Doshi amp has delivered great sound. When I pressed him as to why, he just smiled.

The memory of the sound of the Audio Research 330M monoblock amplifiers ($90,000/pair) at AXPONA 2025 is so vivid I can still recall what I heard and felt. I sat front and center in a room sponsored by Quintessence Audio . . . The sound was so colorful, rich, and effortless—the images so convincing in size, weight, and timbre—that I felt my eyes open wide in amazement.

In high-end audio, Italian designs play by different rules. They tend to favor beauty over austerity, boldness over caution, and emotion over restraint. Rather than just hearing the music, you're meant to be swept away by it. That spirit animates gear from Unison Research, a tube-focused company located just north of Venice.

Tubes, tubes, tubes—how we love to bask in their glow, roll them, and take their second-harmonic distortion into our hearts as if it were a child or a pet. Some may put out so much heat that we have no choice but to open a window, turn on the air conditioning, or listen in the garb of Adam and Eve before that fatal first bite. As they and you age, you can never be sure who's at their best. Tubes, at least, can be replaced, albeit at significant expense...

I haven't reviewed much tube gear, but when I have—Bruce Moore and VTL (in my pre-Stereophile days), Audio Research, and in our September 2022 issue, the towering Octave Jubilee Mono SE tubed pentode push-pull monoblocks—I've been enamored of their sound. I waxed ecstatic about the "captivating beauty" and "heavenly" highs of the Jubilee Mono SEs. I can still recall how gorgeous they sounded; every listen was special.

Hence, my enthusiastic "yes" to a solicitation from John Quick, VP of Sales & Marketing for Dynaudio North America, Octave's North American distributor, to review the smaller MRE 220 SE mono push-pull tube amplifier.

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...

When I was a young man, blind dates were always laced with anxiety. (Proms were even worse. Once, when I arrived in a rented tux and my father's prized dress gloves, my date's father ordered me to take out the trash.)

It would appear that there are still people out there who are unaware that this is the age of the transistor. Not only are tubed amplifiers not vanishing from the face of the earth, they are proliferating. Audio's equipment directory for 1977 listed three tubed power amplifiers. The same directory for 1984 lists over 30 of them, and the Quicksilver amplifier is not even included!