VTL MB 175 Signature monoblock power amplifier
By Michael Fremer   •   October, 1997 Prejudice is bad—whether it's directed at people, places, or things. You know how it goes: digital is "bright," analog is "warm," solid-state is "brittle and etched," tubes are "smooth and soft" dynamic drivers are "low-resolution," electrostats and planars are "high-resolution" copper wire is "smooth," silver is "bright," etc. While putting everything that crosses your path into one box or another makes life simpler and seemingly more organized, the truth, musical or otherwise, usually gets mutilated in the process. Not that we all don't have preferences—but those are not the same as prejudices.

Early in my reviewing career, I switched on a solid-state amplifier only to have it go up in smoke and flames! I had to use my kitchen fire extinguisher to quash the inferno. On the other hand, I owned a pair of tube VTL 300s for about four years, and during that time not one tube blew up or needed replacing. Even the biases on its 16 tubes didn't fluctuate sufficiently to require adjusting. Once something fell off a shelf and shattered a tube—but only the terminally transistorized would use that to argue against valves. And during my almost nine months with VTL's new Signature MB 175s, nothing untoward happened.

Does this mean that solid-state amplifiers catch fire while tube amplifiers are maintenance- and trouble-free? Of course not. But when I hear someone say that tube amps are not for them because tubes are "too much trouble" or "unreliable," or because they "don't want to mess around with changing tubes all the time," I take the time to disabuse them of their silly prejudice.

And now that I've spent the better part of a year with the VTL 175s, if someone tells me they don't like tube amps because they sound soft and rolled-off on top, euphonic in the middle, and flabby and amorphous on the bottom, I straighten them out on that account too. The VTLs are "tubey"-sounding—you'd never mistake them for solid-state—but rolled-off, soft, and flabby they're not. No more than the transistor-driven Rowland Research amps I heard at the January CES sounded thin and wiry.

If looks could kill, the Signature 175 would be a pacifist
There are many sexy-looking tube amps on the market, but VTL's 175 isn't among them—not that it's ugly. If you want an amplifier with dramatic looks, you'll have to look elsewhere—to Cary's open-architectured retro 805s, for example, or Audio Research's Con Edison-ready VT160s, or Scott Frankland's Visible V-8 Wavestream Kinetics, to name three striking-looking tube designs. You've seen the VACs, the C-Js, and the others you can ogle. The boxy, businesslike 175 doesn't make any kind of fashion statement—until you turn it on.

The 175's layout will be familiar to anyone who's ever seen VTL's MB 300 and 225, on whose chassis the 175 was built: six output tubes, three on each side (the 300 and 225 are eight-tube designs), a power and output transformer flanking a pair of large filter capacitors, and two input tubes front and center. The deco-ish front panel sports an on-off rocker and a toggle to switch between 175W of push-pull tetrode amplification and 90W of triode. The rear panel contains line and B+ fuses, RCA and IEC AC input jacks, and custom-made speaker binding posts. Hookup is straightforward, with output transformer taps factory-set at 5 ohms. This gives the amps a chance to provide peak performance with most 4-8 ohm impedance loudspeakers.

No trouble in paradise
As most Stereophile readers know, VTL was founded just over a decade ago by the irrepressible David Manley, who ran the company with his son Luke. The two split a few years ago, the senior Manley starting the company that bears his name, supposedly dedicated to designing and manufacturing tubed studio gear. I say "supposedly" because the company's extensive line includes both a grab-bag of tubed electronics clearly designed for home use as well as solid-state pro electronics.

Despite David Manley's shift into VTL territory, father and son enjoy a friendly if sometimes competitive relationship. Luke has spent the past few years tidying up the company's image and product line while building a nationwide dealer network.