Tube Power Amp Reviews

After I read Brian Damkroger's rave review of the Audio Research Corporation's Reference 5 SE line stage in the November 2012 Stereophile, I was excited about getting the review sample into my system so that I could do a Follow-Up (February 2013). However, the sample had already been returned to the factory, so I called ARC to see if it could be rerouted eastward to me. Chief Listener Warren Gehl answered the phone.

"Sure, you can listen to the Ref 5 SE, but I'd assumed you were calling about the Reference 75 amplifier."

"Reference 75? What's that?"

"It's our newest amplifier—a half-power version of the Reference 150."

The challenge is biblical in character, if not in scope: A half year after railing, in these pages, against our industry's overabundance of products that cost more than $20,000, fate has given me such a thing to review.

I knew nothing of Ypsilon when I first saw its products in a room at an overseas audio show. Even though the speakers in this system were complete unknowns, I was convinced that it was the electronics that were responsible for the magical balance of what I was hearing. That was confirmed when I reviewed the VPS-100 phono preamplifier in August 2009 and PST-100 Mk.II preamplifier in July 2011.

Ever since I became a Stereophile contributing editor, people have asked me, "How do you determine what equipment you're going to review? Do you get to pick your own, or does John Atkinson tell you what to do?"

I've chosen roughly 85% of the components I've reviewed for Stereophile, those choices made on the bases of what I find interesting, and what I think readers would like to know about. It's as simple as that.

It began when I reviewed the MartinLogan Montis loudspeaker (September 2012). The amplifiers I had to drive the pair of them were the PrimaLuna ProLogue Premier integrated ($2999), the Audiopax Mk.II (no longer available; the Mk.III costs $22,000), and the Simaudio Moon Evolution W-7 ($9000). The first two are tubed, with power in the 30–40Wpc range; the solid-state Simaudio puts out 150Wpc. The Audiopax, which sounds great with my Avantgarde Uno Nanos, turned out to be not such a good match for the Montises: weak in dynamics, and too soft sounding. The PrimaLuna and the Simaudio were better overall, each with its strengths and weaknesses, though neither was ideal. I really liked the ProLogue Premier's tonal characteristics, and wondered what a higher-powered tube amp would sound like with the MartinLogans.

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).

Tubes, tubes, tubes.

The amps (and preamps) keep coming.

McIntosh Laboratories is back in the act with a limited-edition revival of the MC275 tube amplifier, the original of which was produced from May 1961 through July 1973—one of the longest model runs in hi-fi history.

New companies devoted to tube gear keep cropping up—in recent years, America's VAC and Cary and Canada's Sonic Frontiers. The same thing appears to be going on in the UK. The pages of British magazines are filled with new tube gear.