Solid State Power Amp Reviews

Not everyone needs a power amplifier that can deliver 888W RMS into 8 ohms or 1776W into 4 ohms. You could say that no one needs one of these—or two, if you want to listen in stereo. Most household AC systems can't even provide enough current to deliver all that power. But Simaudio does build Moon 888 monoblocks, and people do buy them, whether or not they need an amp that weighs about 250 lb each and costs $118,888/pair.

When it comes to amplifiers, ya gotcher tubes, yer solid-states, and yer hybrids. Although amplifier manufacturers would have you believe otherwise, the majority of designs within each category are variations on a few fairly-well-known themes. Everyone agrees that the power supply is extremely important. Most designers try to obtain the amplifier's desired frequency response and distortion characteristics with a minimum of negative feedback. It's also agreed—at least among designers of solid-state amps—that the ability to drive a variety of speakers, including those that present a low-impedance and/or reactive load, is an important priority.

An e-mail from an old audiophile pal: "Herb, my buddy owns a recording studio, and he told me one of his $10k reference amplifiers stopped working and the manufacturer said it would take months to be repaired. So he went online and bought this 60W AkitikA solid-state amplifier to use while his big amp was being repaired. The trouble is, the kit cost only $314. (The studio guy bought his assembled and tested for $488.) Now, he likes the AkitikA more than his broke-down reference amp."

For some years now, I've tried to free myself from playing physical media and get all my music organized on a server. It's not that I don't enjoy handling and playing discs, but it's almost impossible to keep track of them. When my collection was only a thousand or two LPs, I felt I could remember each one individually. But now I have several times that many silver discs, and I know I can't.

When Michael McCormick, president of Bel Canto Design, suggested that I review their Black ACI 600 integrated amplifier, I accepted without hesitation. As wonderful as my reference system may sound, its dCS digital front end alone comprises four boxes and a web of cables complex enough to send many a spider spinning. Given the choice between connecting that front end to a pair of expensive, enormous monoblocks—with their similarly expensive AC cords and equipment racks/isolation platforms—or to a single, visually elegant, 45-lb box that costs $25,000, produces 300Wpc into 8 ohms, and requires only a single power cord and shelf, I think many an audiophile, even those with lots of money, might gravitate toward the latter.

Although PS Audio's Stellar M700 monoblock power amplifier ($2998/pair) is a brand-new design from a team led by engineer Darren Myers, it draws on the company's extensive experience with class-D amplification. Sam Tellig and Kalman Rubinson reviewed PSA's HCA-2 power amp in, respectively, the October and December 2002 issues, and I reviewed their GCC-100 integrated amp in January 2006. The Stellar M700's input stage is the latest version of PS Audio's Gain Cell, which they describe as a "proprietary, fully differential, zero feedback, discrete, class-A MOSFET circuit.

For as long as I've known about high-end audio, I've put Dan D'Agostino, co-founder of Krell, on the same pedestal reserved for the likes of Frank McIntosh, Saul Marantz, Avery Fisher, H.H. Scott, and Sidney Harman. The reason is simple: Dan's the man whose achievements at Krell led me from the harsh sound of my first high-end amp into another dimension, one of truly musical sound reproduction.