PrimaLuna ProLogue 5
The 36Wpc vacuum-tubepowered ProLogue 5 is more authoritative than its rating would lead you to expect, and offers a warm, rich presentation, yet really does not sound “tubey” in any traditional sense, producing clean, deep, tight bass and grand soundstaging. A synergistic match with the companion ProLogue 3 preamp.
These monoblocks may not be fully twice as good as the Khartago stereo amp (see above), but they’re mighty good, improving on the Khartagos in every area (particularly in stereo separation and lower noise). Once again, champagne sound on a beer pocketbook.
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.
Audio by Van Alstine Ultravalve
Sounding more powerful than its 35Wpc would indicate, the 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.
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.
While many amplifiers use Bang & Olufsen’s ICE output device, the SX-1000 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.
Vincent Audio SP-331 MK
The hybrid SP-331MK delivers 150Wpc into 8 ohms and 300Wpc into 4 ohms, and operates in Class A for its first 10 watts. This makes the amplifier somewhat dualnatured. At moderate levels it sounds spacious and naturally balanced (if a tad dark), with good dynamic scaling and fine rhythm and pace. Pushed harder, it sounds more ragged. Overall, it is happiest when not played at its power limit.
Rogue Audio Stereo 90
This tube monoblock combines a rich treble and midrange with a gutsy bass and a clarity unusual in its class. Its one shortcoming is a tendency to push the midrange a bit forward. Even with this, it makes all types of music sound right.