Tube Power Amp Reviews

The VTL 225W DeLuxe monoblocks are very similar to the 300W monoblocks that received such an enthusiastic reception from J. Gordon Holt a year or so ago (in Vol.11 No.10) and, ultimately, most of the audiophile community. Technically, they differ only in output tubes and transformer: the 225W uses EL34s, the 300W uses 6550s. The 225Ws, at $4200/pair, cost $700 less than their more powerful brothers. The question may be raised: Why have two models so close in price and performance? According to David Manley, the 225Ws were built on special order for audiophiles who preferred the sound of EL34s to the 300Ws' 6550s. Demand was so great for the EL34 version that he decided to add it to the line. They look almost identical, the only difference being the smaller output transformer on the 225W and an additional filter capacitor on the 300W's top chassis.

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.

It's been a while since I've had a classic amplifier in my system, and McIntosh Laboratory's MC275 is as classic as they come. Introduced in 1961 as the "powerhouse" of that era's newfangled stereo tube amps (two 75W amplifiers in one chassis!), the MC275 retained its position as the amplifier to own—challenged only, perhaps, by Marantz and a few others—until 1970, when it fell prey to the widespread wisdom that transistors were king and tubes were dead, and the model was discontinued. The MC275 briefly returned in 1993, in a limited "Commemorative" edition to honor the late Gordon Gow, longtime president and chief designer of McIntosh Labs. To everyone's surprise, that edition sold well, and McIntosh, gingerly at first, crept back into the tube business.

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 . . .

Two audiophile buddies of mine both own Rogue Audio M-150 monoblocks. I'd always been impressed with not only the sound quality of the M-150, but also its price. For $4495/pair, I thought my friends got a whole lotta amp for notta lotta dough. In this day and age, it's a rare and wonderful thing to get a pair of monoblocks, made in the US by a real audio company, that give you 150Wpc of tube power for under $5000. When Rogue came out with an update of the M-150, the M-180 ($5495), I thought it might be a good subject for my first full review in Stereophile. John Atkinson thought so too. I also thought it would be interesting to compare the M-180 with the very tube-like and almost identically priced Pass Labs XA30.5 two-channel amplifier ($5500), a sample of which I had on hand. (see my Follow-Uphttp://www.stereophile.com/solidpoweramps/pass_labs_xa305_power_amplifi…; in August 2009).

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

In the name of journalistic ethics (footnote 1) I have to come clean. David">http://www.stereophile.com/interviews/david_manley_tubes_logic_amp_audi… 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.