Tube Power Amp Reviews

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.

Even at its humblest, a 300B is a fine thing. And at its best, this classic triode output tube can deliver some of the most intoxicating music playback imaginable. If tubes are liquor, the 300B is clearly absinthe. (The 2A3 is Cognac, the 45 is Armagnac, the F2a is Tequila, and the EL34 is vodka—which is to say, you can make almost anything out of an EL34, from the repulsive to the sublime.)

One drizzly, gray morning I found myself with an unexpected hole in my schedule and an unusual hankering for doughnuts. Since my move to Portland, Oregon, last August, people from around the country have told me that I just had to try the over-the-top creations over at Voodoo Doughnuts. So I donned my raincoat and walked through downtown Portland for one of Voodoo's fried, raised, and glazed treats. Once inside Voodoo's tiny storefront, I chose two confections: a maple-bacon bar (yep, they put a whole strip of bacon on top of a doughnut), and an Old Dirty Bastard doughnut with chocolate frosting, Oreos, and a peanut-butter topping. They were delicious, and way more doughnut than one man should eat.

"Have you really listened to all those records?"

My guest, an occasionally nice person, didn't mean her question in a nice way. It was pointed and derisive: a needle intended to burst whatever it was that made me think filling a room with thousands of LPs was a good idea. She didn't wait for an answer—it would have been "Not quite"—but I half think she half expected me to see reason on the spot.

For anyone who's been around the audiophile block a few times, Conrad-Johnson Design is a brand that needs no introduction. My first acquaintance with Conrad-Johnson was before I began writing for Stereophile (more than two decades ago—time sure flies fast when you're having fun!). I was in the market for a new preamp, having become convinced that my Dayton Wright SPS Mk.II was the weak link in my system, and had narrowed my choices to two similarly priced products: a solid-state model made by PS Audio (I'm not sure of the model number), and the tubed Conrad-Johnson PV-2ar. They were carried by different dealers, who allowed me to take their preamps home over the same weekend for a direct comparison. I was impressed by both preamps, and was sure that either would represent an improvement over the Dayton Wright, but in the end decided to go for the PV-2ar. I later traded it in on a dealer's demo unit of another Conrad-Johnson preamp, the PV-5. And, as it turned out, one of my first reviews for Stereophile was of Conrad-Johnson's PV-11 preamp.

The Audio Research D-160B has been heavily modified since the D-160A, and uses the same technology as the D-70, D-115, and D-250. It embodies William Z. Johnson's latest transformer and power supply designs, his latest choice of capacitors and resistors, and the same independent regulation of screens, drivers, and front end. D-160s and D-160As can be converted to D-160Bs for $1500.

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.