Tube Power Amp Reviews

The VTM200 is the first Audio Research power amplifier I've reviewed. It took me 13 years, and ultimately I'm glad I'd put that much mileage on my reviewing odometer before tackling what turned out to be a most difficult assignment.

Ah, Brazil...land of coffee, the samba, Pelé, Rio-by-the-sea-o, and tube amplifiers. All right, so perhaps the amplifier connection isn't quite as well-established. But one Brazilian amplifier designer, Eduardo de Lima, has published articles in Glass Audio magazine that are viewed by many as groundbreaking, and his evolving products have been seen at various specialist tube equipment shows. De Lima—president, founder, product designer, and principal owner of Audiopax Sistemas Eletroacusticos—is an electrical engineer who started out designing equipment for a telecommunications company, but since 1995 he's devoted his talents to designing a wide range of audio products, including speakers as well as preamps and power amps.

Victor Tiscareno and Byron Collett of AudioPrism are known in audiophile circles for their complete line of power-conditioning products. (See Barry Willis' omnibus review in the December 1998 Stereophile.) Their intimate knowledge of the ever-capricious electrical supply has resulted in a series of front-end components bearing the company's logo. The flagship Mana Reference monoblocks, under consideration here, represent AudioPrism's collected wisdom and engineering savvy taken to its logical extreme.

The VK-150SE stands tall at the top of Balanced Audio Technology's range. It and its smaller brother, the identical-looking VK-75SE stereo amplifier (or, sans the Special Edition mods, the plain VK-75, footnote 1), are related to BAT's first amplifier design, the VK-60. The company's partners, Victor Khomenko and Steve Bednarski, eventually realized that they'd made enough upgrades to the VK-60 to warrant a new model designation, and in 2000 they discontinued the VK-60. Bednarski explained that while the VK-60 accepted the upgrades with good results, the BATboys felt that, in order to fully realize the full potential of the 6H30 SuperTube, a new platform would be required. Enter the VK-75SE and VK-150SE.

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 . . .

Although I retain a firm hold on the established audio world, and recognize and value all that it has achieved, I feel inexorably driven to make some space in my life for single-ended amplifiers—more especially, those that eschew negative feedback (footnote 1). A classic if costly example of the art is the Cary">http://www.stereophile.com/tubepoweramps/740">Cary CAD-805C, which, to my ears, has earned the right to teach audiophiles what negative feedback really sounds like, and what damage it can do to the musical message when poorly handled. This shouldn't be taken as an out-of-hand dismissal of those many great pieces of electronics and amplification that use negative feedback—it is simply an acknowledgment, or even an assertion that negative feedback generates a sound of its own.

Although one of the most innovative firms in the audio electronics field, the David Berning Company seems determined to keep as low a profile as possible. The company advertises little, does not actively seek out new dealers, and seems content to let potential customers seek it out, as though to say "Okay, here's my product, take it or leave it." Thus, even though both Stereophile and The Absolute Sound, in a rare outbreak of agreement, a couple of years ago declared Berning's TF-10 to be one of the best preamplifiers available, most serious audiophiles are still unaware of the Berning Company's existence. Perhaps the EA-2100 will change that.