Solid State Power Amp Reviews

"Tomorrow we'll go over to Larry Archibald's house and pick up the Threshold amplifiers."

How much amplifier power do you need? Most audiophiles figure a maximum of a few hundred watts per channel—beyond that, you're wasting your money or showing off. Others think that anything more than a few watts will mess up an amplifier's musical coherence or "purity," so they stop there and find uncommonly sensitive speakers, usually compression horns with cone woofers.

Some readers may feel that it is pushing poetic license beyond reasonable limits to call the Krell KSA-50 a "new-wave" amplifier. It has, after all, been around for several years. The Krell KSA-50 is new-wave enough, however, to be an incredibly stiff class-A design, rather than a pseudo–class-A circuit, and its 50 watts per channel are supported by enough of a power supply to drive an arc welder. You get about 70 watts of RMS power with 8 ohms, 150 watts with 4 ohms, and sufficient watts into 2 ohms to threaten my load resistors. There is almost enough power to drive a pair of Apogee Scintillas at their ohm setting—though I'd prefer at least the Krell KSA-100.

"A high-quality amplifier must be capable of passing rigid laboratory measurements, meet all listening requirements, and be simple and straightforward in design in the interest of minimizing performance degradation..."—Cdr. Charles W. Harrison Jr., Audio, January 1956 (footnote 1)

Good things come in threes, they say. Well, three-channel power amps suit me just fine. My main component rack is at the back of the room, so I split power duties between a two-channel amp under the rack to drive my rear-channel B&W 804S speakers and, way at the front, either three monoblocks or a three-channel amp for the front three B&W 802Ds. I do this to ensure that the timbre of the front three channels is consistent. The outstanding performance of the Simaudio Moon W-8 dual-mono power amp (Stereophile, March 2006) almost tempted me to go with a stereo amp and a monoblock, but voicing and balancing a multichannel system with equanimity makes me want as much simplicity as possible. I guess manufacturers and users see it the same way; many new three-channel amps are coming on the market.

The $1200 Counterpoint SA-100 amplifier came up to bat fourth in my listening sessions, behind (in order of appearance) the Adcom GFA-555 II (not reviewed here, but sent along by JA for comparison purposes), the VTL Tiny Triode monoblocks, and the Muse Model One Hundred. Thus, my progression went from bipolar solid-state to tube to MOSFET, with a wide spread of sonic characteristics between them: stygian bass from the Adcom; uncanny spatial presentation and vocal reproduction from the VTLs; and an overall superior sound from the Muse. I was therefore eager to see where the tube/MOSFET hybrid Counterpoint would fall in this group of very different-sounding amplifiers.