High-End Audio Buyer's Guide: Power Amps Under $5000

Equipment report
Solid-state power amplifiers,
Tubed power amplifiers
Cambridge Audio 840W,
Odyssey Audio Khartago,
Sanders Sound Magtech,
Van Alstine FET Valve 600R,
Van Alstine UltraValve,
Vincent Audio SP 331MK Hybrid Power
High-End Audio Buyer's Guide: Power Amps Under $5000

Odyssey Audio Khartago


Although the 130Wpc Odyssey Khartago solid-state stereo amp has been around for better than a decade, it was new to JV until amp- connoisseur Alon Wolf (of Magico) told him he used it in his shop and it was excellent. The Wolfman was right. Although the Khartago doesn’t have all the articulation and transparency of the standard- setting $40k Soulution 710 stereo amplifier, it has a shockingly similar balance (albeit a bit warmer and less transparent), no discernible grain, high resolution, and a deep, wide soundstage. Positively, the best budget amp JV has heard (and the $2k Odyssey Stratos monoblocks are great, too). odysseyaudio.com

AVA Ultravalve


According to Frank Van Alstine, the Ultravalve’s lineage is traceable to the Dynaco Stereo 70, which he denotes as its “great grandmother.” Although not as romantic-sounding as the original, it is far better focused, and in general sounds like a higher-resolution device. It handles bass lines with superb control and good impact and is capable of dishing out plenty of boogie factor. Its ability to retrieve microdynamic nuances allows for the full scope of the music’s dynamic intensity and interaction between musicians to shine right through. avahifi.com

Vincent SP-331 Mk II


The SP-331 is one of the best-sounding affordable power amplifiers we’ve yet heard. A hybrid tube/solid-state amplifier, it combines the harmonic richness and subtlety of fine tube designs—especially through the midrange—with the low-frequency power, control, and agility of a good solid-state amplifier. In the treble the amplifier sounds slightly softer but also more delicate and refined than solid-state competitors in its price range. The SP-331 matches in a synergistic way with today’s best budget solid-state preamps, adding welcome touches of midrange finesse and richness while preserving a taut and well-controlled presentation. wsdistributing.com

Cambridge Audio 840W


The sonic and technical key to the 200Wpc 840W is its proprietary XD topology which runs in Class A at low levels and transitions over to an “enhanced” Class B at higher levels, without the typical crossover distortion normally associated with Class AB designs. Compared to its companion 840E preamp, the 840W amplifier comes off as a bit darker, bloomier, and more relaxed on transients, settling back a row or so in perspective; yet it also has a wide full-blown soundstage and robust dynamics, as well as seemingly limitless power reserves and that familiar, buttery, Class A vibe. On a great full-range loudspeaker the entirety of the low-end suddenly stands at attention via the 840W—complex passages are defined, harmonics focused, and images tightened. Beyond its extension in the bass, the 840W’s dynamic punch comes on spring-loaded and heavy as a Joe Louis right. Designed for bridging or bi-amping, it can be reconfigured in a snap. Simply put, the 840W further complicates the debate about what defines “serious” as opposed to “value” audio—a supernatural deal. audioplusservices.com

AVA FET Valve 600R


Frank Van Alstine’s 300Wpc hybrid amp is based on AVA’s patented forward-transimpedance design. A 12AT7 triode front end is coupled to a fully complementary power MOSFET output stage. The stock JJ Electronic tubes are quite musical, so there’s no compelling reason to tube roll. No, it doesn’t sound like a tube amplifier, but what sets it apart from a host of solid-state designs is its soulful midrange and ability to retrieve music’s drama and tension. Tack on decent spatial delineation and you have the making of a successful hybrid design. It’s a complete package featuring low distortion, superior speed, killer bass, and superb dynamics. The treble is somewhat closed in, and tonally, harmonic colors are on the dark side of reality, requiring careful system matching. At its best, the 600R can sound much like a $20k power amplifier. World-class power amplification at an affordable price. avahifi.com

Sanders Sound Magtech


This no-nonsense amplifier was designed to drive any loudspeaker impedance, particularly full-range electrostatics which can have an impedance of less than 1 ohm in the top octave. The Magtech “sounds as if it had infinite power into anything with total stability,” said REG. The fully regulated power supply is unusual. Delivering 500W into 8 ohms and 900W into 4, and fully stable driving capacitive loads, it is the perfect choice for electrostatics. sanderssoundsystems.com