Basic solid-state power amplifiers are not, due to their essential nature (boxes with parts inside), sexy objects that inspire a lot of audiophile lust. The STA200 will never be accused of looking sexy or especially stylish unless you’re into stark minimalism. But if sound quality and solid-state reliability are your primary purchasing criteria, the STA200 should be on your radar. You may not be blown away by the STA200’s looks, but its sound turns it into one sexy beast.
Wyred 4 Sound ST-500 mkII/ST-1000 mkII
These high-efficiency power amplifiers—delivering 250 and 500Wpc respectively—have got to be among the great bargains in audio. Although they were not accorded a formal review, PS used them to drive the Emerald Physics CS3.2 II speakers, and then for a good month auditioned them on his Quad 2805s. Throughout they performed flawlessly, delivering sound of exemplary clarity and control, perhaps fractionally on the cool side of neutral, but not excessively so and never compromising the reproduction of warmth. Pricing depends upon options (i.e., WBT binding posts, power, etc.).
The NuPrime ST-10 amplifier is what NuPrime calls “near reference class.” Why only “near” reference? As far as reviewer SS can tell it’s because this stereo amplifier only puts out 150 watts per side into an eight-ohm load. The ST-10 is a very quiet, extremely low-noise power amplifier that, as long as it isn’t pushed into clipping, sounds exceedingly neutral and uncolored. The ST-10 did a superb job of driving a variety of speakers with authority and control.
Audio by Van Alstine Ultravalve
The 35Wpc Ultravalve is a thoroughly modern and rationally priced vacuum-tube amplifier. While its perspective is not as romantic as that of its “godmother,” the Dynaco Stereo 70, it is far better focused, clearly more dynamic, and in general a higher-resolution device.
Audio Alchemy DPA-1 and DPA-1M
$1995 and $3990/pr.
Audio Alchemy’s DPA-1 stereo amplifier and DPA-1M monoblock deliver superb sound in an affordable and compact package. Both amplifiers are identical except for output power. The circuit is based on Class A input and driver stages and a switching output section. The DPA-1 offers 125W into 8 ohms, a figure that climbs to 325W with the monoblock. These amps are characterized by outstanding bass extension, control, and authority, coupled with explosive dynamics. They also excel at throwing a huge and three-dimensional soundstage with precise image specificity.
Quad Artera Stereo
This 140-watt-per-channel amplifier—the latest refinement of Quad’s innovative, patented, award-winning “current dumping” technology—is, in PS’ opinion, the finest amplifier the company has ever made by a good margin, and unquestionably the most uncompromised implementation of Walker’s current-dumping circuit.
Wyred 4 Sound SX-1000R
While many amplifiers use Bang & Olufsen’s ICE output device, the SX-1000R combines it with its own direct-coupled, balanced, dual-FET input stage, designed by Bascom King. A powerful amplifier capable of effortlessly delivering copious amounts of power and detail. New Series 2 version currently under review.
Parasound Halo A21
An excellent Class AB stereo transistor amp, designed by the redoubtable John Curl, capable of 250Wpc into 8 ohms (400 into 4 ohms). Though not the last word in solid-state amplification, the A21 offers a lot of power at an affordable price.
Odyssey Audio Stratos
Even if you A/B’d these superb, high-resolution, 180Wpc monoblocks with super-amps on super-speakers (as JV did), you might still find yourself pondering whether the difference in sound justifies the difference in expenditure. That JV ultimately concluded it did is beside the point. The way he saw it, the fact that the Odyssey Stratos monoblocks could give even a picky listener like him pause made them super-amps in their own right. Yes, you can buy better. The question is: Do you really want to?
PrimaLuna ProLogue Six
These beautifully built, affordable, and “hassle-free” 70Wpc monoblocks will alter your preconceptions about tube gear. Indeed, their transient quickness and ability to drive difficult loads may fool you into thinking you’re listening to a very good hybrid. Yet they still have that wonderful tube magic.
A very low-distortion, 100Wpc solid-state amplifier that is virtually flawless when driving stable loads within its somewhat narrow power limits. “A precision instrument designed to perform the precisely defined task of reproducing music and sound accurately, which it does essentially to perfection,” says PS.
Rogue Audio Hydra
Rogue Audio has got something with this hybrid, “tubeD” stereo amp. Not merely a tube circuit placed in front of a Class D output section, it creates a sound completely unlike those first Class D amps that bit your ears. Fast, powerful, and resolving, the Hydra reproduces instrumental tones and timbres with accuracy and texture, has good spectral balance, and creates a consistently broad and vivid soundstage. Though GH found an occasional lack of top-end smoothness in the sound of orchestral strings, he noted owners could tailor its presentation by rolling input tubes.
NAD Masters M22
The partner to the excellent M12 preamp/DAC, the M22 is a 250Wpc hybrid Class D amplifier that uses the latest nCore amp technology licensed from Hypex. A paradigm of power and touch, its bass response is startling in its boldness, extension, and iron-fisted grip. It goes deep, exploring more of the dynamic contrasts and harmonic complexities that define the timbre of a bass drum or skin of a tympani or the drumhead of a tom-tom. But the M22 is not just about the bottom octaves—particularly rewarding was the broader more crisply defined frequency extension, color, and open-window transparency. A serious and masterful effort.