Solid State Power Amp Reviews

I first met electronics engineer John Dawson in 1979, at a British audio show. The company he'd co-founded, A&R Cambridge, had just launched the A60, a slim, elegant-looking, 40Wpc integrated amplifier costing only £99 (then equivalent to $217).

By the time I reviewed the Mk.2 version, in the October 1984 issue of Hi-Fi News & Record Review, the A60's price had risen to £199 ($248), the company was now called Arcam, and more than 22,000 A60s had been sold, making it one of the best-selling amplifiers in England. While preparing that review I had visited Arcam's factory, near the English town of Ely, where Dawson had shown me filing cabinets containing a separate manufacturing report for each and every one of those A60s.

Class-A amplifiers have a well-deserved reputation for being power guzzlers that run hot enough to burn fingers. They're inherently inefficient because their output devices conduct full current at all times, and much of that current is dissipated as heat—requiring, in the case of class-A solid-state amplifiers, massive heatsinks. This is why class-A amps tend to produce relatively low power, and tend to be heavy and expensive to buy and run. And these days, energy inefficiency is out of fashion.

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.

Of the hundreds of product reviews I have written over the years, it is perhaps those of power amplifiers that present the hardest task in defining their worth. This is not because power amps are unimportant. As I wrote in my review of the MBL Corona C15 monoblock, in June 2014, "it is the power amplifier that is responsible for determining the character of the system's sound, because it is the amplifier that must directly interface with the loudspeakers. The relationship between amplifier and loudspeaker is complex, and the nature of that relationship literally sets the tone of the sound quality." But because the amplifier's role is so fundamental, it can at first be difficult to determine a given amp's balance of virtues and failings. A paradox.

Stereophile normally doesn't review audio systems. We review individual components. We've made an exception for the Bel Canto Black system because it deserves to be evaluated as such. It consists of three dense, almost identically sized cases of black-anodized aluminum. One, the ASC1 Asynchronous Stream Controller, is what in a conventional system would be called a "preamplifier." The other two, a pair of MPS1 Mono PowerStreams, would in a conventional system be called "monoblock power amplifiers."

Google Bricasti and all that comes up are sites relating to Bricasti Design products. The name must be fanciful—it sounds Italian, but cofounders Brian Zolner and Casey Dowdell most likely are not, and the company's headquarters are not in Milan or Turin but in Massachusetts.

While its name might be whimsical, nothing else about Bricasti is. As John Marks reported in his review of Bricasti's M1 DAC in the August 2011 issue, both founders previously worked at Lexicon: Dowdell as a DSP-software engineer, Zolner as international sales manager. Bricasti develops its products in conjunction with Aeyee Labs, formed by a group of ex-employees of Madrigal Audio Laboratories and based in New Haven, Connecticut.

Several seconds after I began listening to it, I knew that Theta Digital's Prometheus monoblock amplifier ($12,000/pair) was different from other amplifiers. The violins and brass were more dynamic, and had more pace. The orchestra sounded more three-dimensional, depicted in relief by a degree of hall ambience I hadn't heard when I played the same recording through my reference solid-state stereo amplifier, a Mark Levinson No.334.