Solid State Power Amp Reviews

James Bongiorno, the engineer behind the Sumo Andromeda, has enjoyed a long and colorful career as an audio amplifier designer. He has cast himself at times as an enfant terrible, exploding at audio critics and running scandalous advertisements (footnote 1). His best-known amplifier is the Ampzilla, produced by Great American Sound, but he also designed the Dyna 400. Currently Jim is living on a boat and serving as part-time consultant to the Sumo Company.

Imagine if you can a power amplifier with the bass richness, midrange liquidity, and high-end accuracy of the best tube amplifiers, and the inner detail, transient attack, and bass solidity and range of the best solid-state amplifiers. If you can imagine that, you can visualize what this amplifier sounds like.

This is something we don't see too often: an entirely new approach to power amplifier design. As Quad points out in its literature for the 405, class-A operation of transistors provides the lowest distortion, but drastically limits the amount of power an output transistor can deliver without overheating. (Most transistor amps use class-AB output operation, in which each of a pair of power transistors handles part of each signal cycle and shuts down during the other part. Imperfect synchronism between the two halves causes the familiar "crossover distortion," which accounts for most solid-state sound. In class-A operation, each output transistor draws current though the entirety of each signal cycle, eliminating the crossover transition but doubling the amount of time current is drawn, and thus tending to cause the transistor to heat up more.)

It takes a lot of courage for a new company to launch an amplifier like this at time when most manufacturers are courting the mass market with budget-priced receivers, and Marantz is pretty firmly established as the Rolls Royce of audio electronics.

The SAE Mark II has, nominally, the same performance specs as the Dynaco Stereo 120, yet it costs twice as much as a factory-wired Stereo 120, and about 2½ times as much as a Stereo 120 kit. Is the SAE really worth the difference? And how does it compare with some other $400 amplifiers? Well, it all depends.