Viola Audio Laboratories Crescendo Preamplifier and Concerto Power Amplifier


Equipment report
Solid-state power amplifiers,
Solid-state preamplifiers
Viola Audio Laboratories Concerto,
Viola Audio Laboratories Crescendo
Viola Audio Laboratories Crescendo Preamplifier and Concerto Power Amplifier

The Concerto’s output stage is built around a fairly new transistor technology from Motorola called ThermalTrak. The transistors have five leads rather than three, and incorporate a diode within the package that reacts to the transistor’s temperature. Specifically, the voltage drop across the diode changes with temperature, and this voltage drop fine-tunes the bias current on a moment-to-moment basis. Viola has taken this idea to the next level by including a microprocessor that adjusts the overall bias level within which the ThermalTrak system makes fine, short-term adjustments.

The only chink in Viola’s armor is its woefully inadequate owner’s manuals. Products of this price, sound quality, and execution deserve professionally written and produced documentation, not a few photocopied pages inserted into a plastic Office Depot cover that falls apart. More importantly, the quality of the writing and the organization of the contents of the manual are sadly lacking. For example, the first two sentences of the “Quick Start Guide” are: “Prior to crescendo version, any crescendo leaves the Viola facilities with the default factory setup to create its own network named ‘crescendo’ and assumes a network IP of with an IP mask of On a point to point network on versions prior to, all IP addresses on the network are to be static.” This doesn’t appear buried in the back of an owner’s manual, but is the first paragraph on the first page of the Quick Start Guide. Oy.

The owner’s manual, however, is a microcosm of a larger picture I garnered of a company that is totally engineering driven. Viola has no consistent look among its products, offers only very-high-end preamplifiers and power amplifiers (no integrated amps, CD players, DACs, or other products to “round-out the line”), has never pursued the entry-level or even mid-level customer, seem to relish its low profile in the market, never advertises its products, and creates the kinds of components Jayson is interested in designing rather than what the market asks for. The picture that emerges is of a designer, Paul Jayson, who has dedicated the last 35+ years of his life to perfecting cutting- edge amplification circuits—to the exclusion of all else.

But as we’re about to discover, that path has its own glories.

I hinted in the introduction that these Viola products were quite a discovery, and indeed they are. Starting with analog input signals (we’ll get to the Crescendo’s DAC performance later) from a dCS Vivaldi or Basis Inspiration/Air-Tight PC-1 Supreme/Simaudio 810LP, the Viola pair was startling in its speed, transparency, and resolution. Instruments and voices were right there, vivid and alive in ways that rivaled any amplification I’ve heard. The treble, in particular, had a realism and tangibility that were simply sensational. This was the result of an extreme transparency and clarity that seemed to strip away all sense of anything imposing itself between me and the music. Listening to music through these electronics was like taking one significant step closer to the original performance. Here’s an analogy. I live near the California coast and walk every morning. When I leave the house the rolling hills and vistas are often softened by a light shroud of moist ocean air. By the time I get back and the sun has ascended and burned off the moisture, the same landscapes appear more vivid, with greater clarity of detail and a richer, denser color palette. That’s what the Viola electronics sound like; lifting the electronic haze renders an immediate increase in clarity and palpability.

This quality was particularly pronounced in the treble, which was simply sensational, among the best I’ve heard from a small handful of the best electronics. I’ve been listening lately to a terrific hybrid SACD from 2003, Roy Haynes’ Love Letters with Christian McBride, Dave Holland, David Kikoski, Kenny Barron, John Scofield, and Joshua Redman. It’s a musical triumph, made all the better by the stunningly great sound quality (it’s an original DSD recording). The Viola electronics rendered Haynes’ cymbal and snare work with such clarity and precision that they fully conveyed the measure of his genius. He creates very fine gradations of dynamic expression that perfectly complement the melody or the soloist’s expressions. Moreover, the drums and cymbals have a sonic tangibility that’s breathtaking. I heard a new wealth of subtle inflections and nuances in his performance through the Viola electronics, not to mention a far more convincing illusion of the drum kit appearing in my listening room. The top end was finely textured and highly nuanced, conveying a fresh abunance of inner detail.