Solid State Power Amp Reviews

When I reviewed the Mark Levinson No.536 monoblock, I said that its sound quality was second to none. However, its stratospheric price of $30,000/pair unnerved me—only seven of the 35 top-rated solid-state power amplifiers listed in the April 2017 edition of Stereophile's "Recommended Components" cost more, and a similar number (not the same models) deliver more power into 8 ohms. "But don't despair," I wrote—"Mark Levinson has just released a less expensive version of the No.536: the dual-mono, 350Wpc No.534 stereo amp ($20,000)." I requested a review sample of the No.534, to see if it matched the No.536's outstanding qualities of build and sound.

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.

There seems to be an inexhaustible supply of amplifiers; it's hard to choose which ones to review. Big-name operators are difficult to ignore, while smaller outfits often complain of neglect. In the case of a new and moderately priced introduction from Krell there's no need to find excuses: it's available, it's likely to be important judging from this company's track record, and we'd all like to see just how well it performs.

This review features the KST-100 stereo power amplifier. Initially this product was differentiated from the more expensive Krell components by having an all-black livery. However, as customers showed a preference for Krell's traditional anthracite finish, the KS series is now also available in this finish.