Tube Power Amp Reviews

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 VTL MB-450 series began life in the late 1980s as the Deluxe 300, a pair of which I once owned. Over the years the basic design has been improved and modified, in the forms of the MB-450 (1996) and the MB-450 Series II (which I reviewed in January 2008). The tube complement remains the same: eight 6550s in the push-pull output stage, a 12AT7 input tube, and a 12BH7 driver. Into a 5 ohm load, the MB-450 III is claimed to produce 425W in tetrode mode or 225W in triode, from 20Hz to 20kHz.

I hate audio shows. All those manufacturers and retailers desperately demonstrating their products, knowing how impossible it is to do them justice in a hotel room. They might be saying, "It has gold-plated circuit boards and unobtainium binding posts," but all I hear is Please love it, please love it, oh puhleeze . . .

Step 1: Find something that works. Step 2: Use it. Step 3: Repeat as necessary, then retire.

Stop me if you've heard this one: Back in the early 1990s, just after the fall of the Soviet Union, I debated professor of music engineering and magazine columnist Ken Pohlmann on a talk show on the CBS radio network. The subject was analog sound vs digital sound, but I guess when Pohlmann felt I was getting the upper hand, he felt he needed to play the tube card. Derisively, he said, "I bet you're one of those tube guys, too, aren't you?" Before I could open my mouth, he continued: "You know, the Soviet Union's military gear, including the MIG fighters, ran on tube electronics, and look what happened to them!"

When I attend Stereophile's annual Home Entertainment show, I rarely sit and listen to music for very long. Instead, I try to hit every room, press the flesh, find out about new products, and play a little jazz.