Tube Power Amp Reviews

In the name of journalistic ethics (footnote 1) I have to come clean. David Manley once gave me a gift. He presented me with a large, rather heavy, Russian-made watch at the 1995 Las Vegas WCES. A very manly watch: In fact, it said "Manley" right on the dial. The watch worked fine for about six months. Then it developed a very subjective approach to timekeeping. Time stood still, and my life wasn't even passing before my eyes. The watch has become a nice, albeit slightly ugly, mini–boat anchor; now my rubber ducky stays where I put it in my bathtub.

Many audiophiles who have only recently subscribed to Stereophile will be surprised to find that those clunky, heat-producing, short-lived tubes that reigned up through the mid-'60s are still Executive Monarchs in the mid-'80s. Why, for Heaven's sake? Because, despite everything, people like them.

Neither its rather pedestrian name nor Manley Labs' own literature gives much of a clue as to the 175 monoblock's special pedigree. Where are the bands, the fanfare?! After all, the rolling-out of a 6L6–based high-power audiophile-grade tube amplifier definitely qualifies in my book as a momentous occasion. Deplorably, such happenings are rare indeed; the 6L6 has been unjustly neglected in high-end circles.

Based in the Czech Republic, KR Enterprise is headed by an occasionally gruff Dr. Riccardo Kron and his American-born wife, Eunice, who operate the company out of a partially abandoned factory that was once part of the state-owned Tesla High Vacuum Technology facility in Prague. The Swiss-funded company is unique in that it manufactures both amplifiers and the tubes that power them. KR's tubes have found favor with other amplifier makers as well—especially the 300BXS, electrically identical to a standard 300B but rated at 25W in class-A.

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!"

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 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.