The road to hell is paved with good inventions: clever ideas that appear, in hindsight, motivated more by a desire to sell clever ideas than to make musically superior products.
The DiaLogue tube amplifiers from PrimaLuna have, at their heart, a clever idea of their own: an output circuit that is user-switchable between triode operation, in which the screen grid of a tetrode or pentode power tube is defeated by means of connection to the tube's anode; and Ultralinear operation, in which the screen grid of a tetrode or pentode carries a portion of the AC music signal, supplied by a tap on the output-transformer primary, in a feedback-like effort to reduce distortion and increase power. Fans of the former often report a sweeter, more tubey sound, while fans of the latter report a tighter, more detailed, more timbrally neutral sound. Audio enthusiasts are given to reporting any number of things.
Domestic audio is based on two simple processes: transforming movement into electricity and electricity back into movement. Easy peasy.
Audio engineers have been doing those things for ages. Have they improved their craft to the same extent as the people who, over the same period of time, earned their livings making, say, automobiles and pharmaceuticals? I don't know. But if it were possible to spend an entire day driving a new car from 50 years ago, treating diabetes and erectile dysfunction with the treatments that were available 50 years ago, and listening to 50-year-old records on 50-year-old playback gear, the answer might seem more clear.
"We put music in the souls of our amplifiers. Every amplifier, every tube, every transformer has music in its soul."
Not to be cynical, but I've heard, over the years, countless variations on that sentiment. Not to be naïve, but it rang with somewhat-greater-than-usual sincerity when given voice by 45-year-old Richard Wugangfounder, with his late father, of Virginia-based Sophia Electric, Inc.
Even as the gulf narrows between the sounds of the best solid-state and the best tubed amplifiers, most listeners remain staunch members of one or the other camp. Similarly, when it comes to video displays, the plasma and liquid-crystal technologies each has its partisans, though that conflict's intensity is relatively mild, perhaps because video performance, unlike audio, is based on a mastering standard that establishes color temperature, gray-scale tracking, color points, and the like (I'm deeply in the plasma camp). But in audio, the "standard" is whatever monitoring loudspeaker and sonic balance the mastering engineer prefers, which makes somewhat questionable the pursuit of "sonic accuracy." Still, in a power amplifier, a relative lack of coloration is preferable to amps that Stereophile editor John Atkinson has characterized as "tone controls"usually, if not exclusively, of the tubed variety.
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 amplifiera 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.
Do you believe in beginner's luck? If so, some of your personality traits should be quite predictable. Let's see. You're very likely an optimist with a "bull-market" mentality, play the lottery, and, most important, bought a CD player within a year of its introduction, or a solid-state amp in the '60s. You're apt to mail in a profusion of bingo cards (you know, the kind Stereo Review is full of) and spend hours perusing specifications in the hope of finding a kernel of truth in all of that chaff. You'd particularly be appalled at that fellow I ran into the other day, who had bought an AR-1 in 1956 and waited another decade before buying another speakerjust to make sure stereo wasn't a fad. Hey, relax, I won't turn you in; the mere fact that you're reading Stereophile is sufficient reason for redemption.
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 3040Wpc 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.
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.
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 ampsa 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).
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 1973one of the longest model runs in hi-fi history.
New companies devoted to tube gear keep cropping upin 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.
Owning a powerful tube amplifier is like owning a classic automobile. Great pleasure may be had, but ownership involves a little more care and maintenance than usual.
Jadis, an audiophile company specializing in all-tube amplifiers and operating out of a small French town, has enjoyed a good reputation for some years, even if some of its models have suffered from the reliability problems that occasionally afflict the largest tube amps. Another problem area is that of power consumption and heat output. In common with class-A amplifiers and high-bias A/B types, including solid-state models, larger tube amps give off substantial heat. The Defy-7's 240W idling consumption may or may not be welcome, according to your location and the season.
It's always good to have a reference. No matter the endeavor, references help guide us and set standards for all we do. For many hours of every day, I'm lucky to enjoy the reference of live, unamplified music. Right now, I average over 20 hours a week of rehearsals and performances of various ensembles, and four to five hours of listening to recorded music on my hi-fi. Clearly, for me, my musical reference is not the sound of my audio system, but the sound of live music created in various venues and acoustics.