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

This brings me to another of the Concerto and Crescendo’s great strengths, its rendition of transient information. These electronics are lightning-fast—Spectral and Constellation fast— yet they have no artificial etch that would impart a mechanical or sterile character to the sound. The Viola reproduces transient sounds the way instruments do in life, with sometimes startling attacks and quick decays. Some electronics can sound fast through the treble, but exhibit a kind of discontinuity because the midrange speed doesn’t match that of the top end. The Viola electronics totally avoid this pitfall. In fact, they exhibit a degree of transient coherence, from top to bottom, that is as startling in its sonic achievement as it is in the musical result. Drums fairly jump from the presentation. Even low-level transients sound highly realistic through the Viola. Midway through Joe Pass’ great solo on “Contractor Blues” from the LP 88 Basie Street, the drummer sets the rhythm with gentle rim shots. Through the Viola these are not just undifferentiated transient noises, but instead sound like wood hitting the rim of a snare drum.

This transient performance served piano particularly well, highlighting the fact that the piano is a percussion instrument. The explosive dynamics from, say, Bruce Katz’s instrument on the superbly recorded AudioQuest CD Crescent Crawl or Minoru Nojima’s Hamburg Steinway on Nojima Plays Liszt were nothing short of sensational. Again, this electrifying transient speed was not the result of an artificial hype that quickly grows tiring. Rather, the Viola electronics simply had the speed and wide dynamic envelope of the real thing.

Speed, resolution, and transparency are often accompanied by a tendency toward leanness, lack of body, thinning of tonal colors, and a bottom end that favors precision over visceral weight. That was not the case with the Concerto and Crescendo. In addition to a full-bodied tonal balance, the Viola pair’s bass was phenomenal. These electronics combined deep and effortless extension at the extreme bottom with a visceral muscularity in the midbass that created a powerful physical involvement with the music. The huge left-hand chords in the previously mentioned Nojima Plays Liszt were thunderous and spine-tingling. The Concerto seemed to have an iron-fisted control over the Magico Q7’s woofers, showcasing this speaker’s remarkable combination of pitch precision, lack of overhang, extension, and sheer bottom- end verve. Despite its rating of “only” 100Wpc, the Concerto sounded like a powerhouse, with no softening of bass drum impact at high playback levels or any sense of dynamic compression. The only other amplifiers I’ve heard in my own system with this quality of bass were the Jeff Rowland 725 monoblocks I reviewed in Issue 228.

These impressions were made listening to the Concerto and Crescendo being fed analog signals from a dCS Vivaldi, Aesthetix Romulus CD player/DAC, and my LP front end. How does the Crescendo’s integral DAC sound? I connected my MacBook Pro running iTunes and Pure Music to the Crescendo via USB, and alternately to the dCS, and Aesthetix, with the dCS and Aesthetix feeding the Concerto’s balanced analog inputs. I found the Crescendo’s integral DAC to be excellent, but not at the same level of achievement as the Concerto and Crescendo’s analog circuits. The Concerto and Crescendo are so good that anything less than a superlative source prevents them from achieving their full potential. The Crescendo’s DAC was fairly dimensional, clean in timbre, and wide in dynamics, but it did impart a bit of hardness and sheen to the treble, along with a reduction in transparency and immediacy. The exquisite, finely filigreed top end which sets these electronics apart as special was still apparent, but not to the same degree as when the Crescendo was fed an analog signal from the Aesthetix or, especially, the dCS. If the Crescendo and Concerto weren’t so spectacular, the DAC wouldn’t have come under such a critical ear.

The Viola Audio Laboratories Crescendo and Concerto are simply stunning musically, and among the best electronics I’ve heard. The transparency, the sense they convey of nothing coming between you and the music, their sensational treble resolution without a touch of the analytical, their wide dynamic expression, and their absolutely sensational bass vault the Viola electronics to world- class status.

Throughout this review I’ve felt the urge to temper my praise of these electronics only because these are the company’s “entry- level” components—what are Viola’s $69,000 Spirito preamplifier and $59,000 Legacy 100W pure Class A monoblocks capable of? It’s mind-blowing to consider that one of the following statements must be true: 1) the Crescendo and Concerto are very close in sound quality to Viola’s reference-level products; or 2) Viola’s top- of-the-line electronics are in a league that I’ve never experienced.

Whatever the case, you should seek out and listen to these extraordinary electronics for yourself. Viola products may be difficult to find, but you may consider them to be as great a discovery as I do.


Inputs: Three balanced on XLR jacks, three unbalanced on RCA jacks, one SPDIF, one USB
Outputs: One balanced on XLR jacks, one unbalanced on RCA jacks, tape-out on RCA jacks
Network connection: Wi-Fi
Viola Local Network (link bus): CAT-5
Gain: 16dB or 26dB (switchable)
Supplied accessories: Apple iTouch, pre-configured Wi-Fi router, Ethernet cables
Dimensions: 17.5" x 3.5" x 15"
Weight: 25 lbs.
Price: $22,000

Concerto Stereo Power Amplifier
Power output: 100Wpc into 8 ohms, 200Wpc into 4 ohms
Inputs: One balanced on XLR jacks, one unbalanced on RCA jacks
Viola Local Network (link bus): CAT-5
Dimensions: 17.5" x 3.5" x 15"
Weight: 53 lbs.
Price: $22,000