Tube Power Amp Reviews

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.

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-Up in August 2009).

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

Although I'll be spending most of my time at Stereophile reviewing affordable gear, I will from time to time examine so-called "trickle-down" designs from high-end designers who have made their mark in the upper-price echelons. More and more, such designers are taking what they've learned and applying it to less-expensive products in order to broaden their customer base. Cary Audio Design, for example, of single-ended triode fame, has entered the ring with the SLM-100 pentode monoblocks.

My reviews always begin in bizarre ways. Take David Manley...please! (Just kidding.) On the last day of Winter CES 1995, I found myself towing a tuckered-out JA to a few final rooms. (This was just after the January '95 David Manley/Dick Olsher tube-rolling brouhaha, footnote 1, regarding who should do what to whom, and with which particular tube.) So as we passed Manley's room, John Atkinson thought to stick his head in (the noose) and say hello.

Remarkably, I set out to audition the Hyperion HT-88 amplifier ($2800/pair) over two years ago, only to be confounded by shipping errors, miscommunications, and, in the end, a stealthily defective tube. I almost gave up.

The last time I was in England, I happened to be rummaging through some boxes in my mother's garage, boxes containing photographs, my old school books, concert programs, diaries, postcards—all the bric-a-brac you collect throughout your life that you'll never have a need for and can never discard. If anything, such rubbish is perhaps the nearest thing to roots that anyone can have these days. Among the boxes was an amplifier that had been an everyday companion of mine for many years, the vintage Vox AC100 I had used to amplify my Fender bass when on the road.