Tube Power Amp Reviews

Brian Tucker, the US Quad importer, introduced me to the Woodside MA50 tube amplifiers and their manufacturer, John Widgery, during the 1992 Summer CES. Tucker's combination of Woodside MA50 tube amplifiers and Quad">http://www.stereophile.com/floorloudspeakers/416">Quad ESL-63 USA Monitors sounded unusually neutral, dynamic, and detailed. This was good news; back in 1987, Dick Olsher (Vol.10 No.6, pp.104–5) was unable to recommend an earlier Woodside-manufactured amplifier, the Radford STA 25 Renaissance. Brian mentioned that the MA50's design is a much-improved version of that earlier Radford model. Time for another review.

Lee de Forest filed for a US patent on his "Audion"—the first triode—on October 25, 1906, but never could explain why it worked (footnote 1). It was up to Armstrong and Langmuir, in their pioneering work, to place the hard-vacuum triode on firm scientific ground. When the US entered World War I in April 1917, the Army had to rely on French tubes. Six months later, Western Electric was mass-producing the VT-1 receiving tube and the VT-2 transmitting tube. However, it was only in the decade following World War I, as designers became conversant with the triode amplifier, that many of the crucial elements of tube amplification were nailed down. Technical issues such as coupling two gain stages and selection of optimal coupling impedance were already resolved by the mid-1920s. The triode ruled supreme until the tetrode came along in 1926, followed in 1929 by the pentode from Philips's research laboratories in Holland.

Ron Cox, Zen master and good friend from Zuni, New Mexico, gingerly navigated the crowded streets of Amp City—the essentially all-tube amp collection sprawled on my listening-room floor between the speakers. Ron had no trouble spotting the four chrome-and-black chassis of the JA 200s. He pointed a tentative finger: "Are those the Jedi?"

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.

It was back in the mid-'70s that David Berning made a name for himself in the Baltimore-Washington area as an avant-garde designer—someone with a truckload of fresh ideas about tubes. At the time, though Audio Research was starting to crank out pretty decent amplifiers, tube design was pretty much reduced to a rehash of the Williamson circuit and the Dynaco mod of the month.

I dig tube amps. When all's said and done, good tube amps seem to sound more like real life than most solid-state gear; even after listening to and enjoying the hell out of musical solid-state designs like the Audio Research D-240 II and the Muse Model One Hundred, once I hook up the big VTL Deluxe 225s again it's just like going home. I could go on about timbral accuracy and clearer midrange textures, but the bottom line is, music just plain sounds better when you shoot it through good tubes, and once most people experience that magic, they're hooked.

"It's the difference between a stuffed dog and the real thing," said Gunter (George) Bischoff, of Melos Audio, on the difference between solid-state gear and tubes. "The real dog may piss on the rug, needs visits to the vet, gets fleas, has to be walked, but it's a living thing—a real dog. The stuffed dog requires no care, needs no maintenance, but has no life."