here is a bit of info...I got on the inside:)
Viola Labs - An Overview
Viola Audio Labs was founded in 2001 by Tom Colangelo and Paul Jayson, the two key designers who had
worked with Mark Levinson at Mark Levinson Audio Systems(MLAS) and later at Cello.
Whilst at MLAS, Colangelo was responsible for the design of the ML-1, ML-2, ML-3, ML-4, ML-5, ML-6, ML-
6A, ML-7, ML-7A, ML-8, ML-9, ML-10, ML-11 and ML-12 products. At Cello, Colangelo and Jayson
designed among other products the Audio Suite, Audio Palette, Encore preamplifiers, Performance
amplifiers, RDAC D/A converter and the Stradivarius speaker line. They have therefore been responsible
for some of the most important high end audio products produced the last twenty years, which gives them
the most consistent success record of any design team in the industry.
Their objective with Viola Labs is to design products that are sonically neutral, as they believe that only
through sonic neutrality can the listener truly be drawn into the music and experience the essential emotion
within the music.
Taking their earlier work at Cello as a baseline and by paying meticulous attention to all aspects of the
manufacturing process from design, through build and test, to final inspection and packing, they are
producing a product of the highest possible quality that will maintain its performance and give great pleasure
to the owner over a life time of use.
The present line-up comprises:
Reference Series
Spirito Reference Pre Amplifier US Retail Price US$35,000
Bravo Reference Power Amplifier US Retail Price US$29,800
Classic Series
Cadenza Pre Amplifier US Retail Price US$16,000
Symphony Power Amplifier US Retail Price US$16,000
All of the above are now available and being shipped, though supplies of the Symphony power amplifier are
limited as this has only recently been released and Viola are still fulfilling a backlog of orders to Japan.
Future high-end products from Viola will include mono-block power amplifiers, an active cross-over and a
phono amplifier.
Distribution has already been appointed in Germany, Japan, Hong Kong, China and Thailand.
The Cello products were always popular in Japan and the Viola line has been even
more enthusiastically received. The Spirito and Bravo have received several
awards in the Japanese high end magazine Stereo Sound (shown left). Colangelo
and Jayson's work at MLAS and Cello also received numerous "State of the Art"
and "Component of the Year" awards from this influential magazine.
At the Japanese High End Audio Show last year the Spirito and Bravo enabled
Viola Products to receive the "Best Sound" award. Viola products also received
"Best Sound" awards last year at shows in Thailand and Beijing.
Brief details of each product are given below:
The Spirito is a modular preamplifier that uses open architecture to give the maximum flexibility for
customisation, upgrading and expansion. It offers a level of transparency and musicality that is state-of-theart.
The unit comprises a mainframe with a separate power supply chassis. The mainframe has one slot
reserved for a dedicated controller card and ten open card slots that are loaded from the rear and permit the
unit to be configured to suit a wide range of applications. The basic Spirito configuration requires one V20
input card (3 inputs - 2 balanced and 1 unbalanced) and one V30 output card (3 outputs - 2 balanced and 1
unbalanced). Both cards occupy two slots. Future developments will include D/A, Phono and EQ modules.
Discrete volume and balance controls are located on the front panel. All other unit functions are controlled
by a large touch sensitive display, also located on the front panel. This allows the unit to be easily
configured and controlled in stereo, multi-channel and multi-room modes. Inputs can also be named
according to the source connected to them.
Software is supplied with the unit to allow a Palm Pilot to be used as a remote control for the Spirito via an IR
link. New software for the controller card may be easily loaded to allow the addition of new functions.
The Spirito uses Class A discrete circuitry and is fully balanced throughout. Future development will provide
opportunity for phono stages, DAC and EQ stages.
An innovative method of chassis construction allows all fixing screws to be hidden from sight.
Dimensions:
Spirito: 44.7cm W x 20cm H x 51cm D
PSU: 44.7cm W x 11cm H x 51cm D
Weights:
Amplifier: 4.5kg
PSU: 4.9kg
More details of the system is given in the attached Spirito user manual.
The Bravo Amplifier is a 350W stereo power amplifier with a separate power supply. Like its pre-amplifier
partner the Spirito, the Bravo offers a level of transparency and musicality that is state-of-the-art.
The amplifier can be converted to a mono amplifier and operate in either of two modes - Internal Bridge
Mode or Internal Parallel Mode. Internal Bridge mode is better suited for high impedance loudspeakers (4
ohms and above) that require more voltage. Internal Parallel Mode is better suited for lower impedance
loudspeakers (4 ohms and below) requiring more current. The picture above shows a pair of Bravos (top)
with their power supplies underneath.
The use of a separate power supply prevents Electro-Magnetic Interference (EMI) produced by the mains
transformer and other inductive components from having any effect on the audio circuitry. The Bravo power
supply is uses what is referred to as an Inductor Input System. This avoids the high peak current demands
that would be placed on the mains supply by a conventional power supply design and therefore minimises
inter-modulation distortion on the power supply rails and ground returns. It is also relatively unaffected by
power supply voltage variations compared to conventional designs. An additional benefit of this technique is
that it reduces the stress on the key power supply components, leading to higher reliability and longer life.
Viola amplifiers are designed to ensure highly controlled behaviour under all conditions of use. Particular
care has been paid to the overload conditions that are often encountered under normal use. Soft clipping
circuitry is used to limit sonic degradation if the amplifier is overdriven (voltage overload). Bandwidth control
results in nearly identical small signal and large signal frequency responses. This approach avoids slew rate
limiting (frequency overload). In order to ensure accuracy in the time domain, the bandwidth control has a flat
group delay characteristic. This implies a linear phase verses frequency relationship and means that all
signals pass through the amplifier with the same amount of delay. In plain English the output signal looks
exactly like the input signal, only bigger.
Great efforts have been made to minimise distortion at lower frequencies, because the majority of energy is
encountered at these frequencies in most music. Obtaining low distortion without the use of large amounts of
corrective feedback requires the use of more output devices and more refined lower level stages.
An innovative method of chassis construction allows all fixing screws to be hidden from sight.
Brief Specifications:
Output Power: 350W per channel into 8Ω
1,000W per channel into 4Ω
1,200W continuous average power into 8Ω when in Bridged Mode
2,500W continuous average power into 1Ω when in Parallel Bridged
Mode
Inputs: 1 x Balanced
1 x Fischer
Outputs: 3 pairs of WBT terminals per channel
Frequency Response: 10Hz to 20kHz ± 0.15dB
10Hz to 100kHz, -3dB
Power Bandwidth: 5Hz to 100kHz
THD: Less than 0.1% @ 20kHz and 350W
SN Ratio -105dB @ 1kHz 350W, C weighted
Dimensions:
Amplifier: 44.7cm W x 23.5cm H x 66cm D
PSU: 44.7cm W x 23.5cm H x 66cm D
Weights:
Amplifier: 39 kg
PSU: 57kg
The Cadenza is a wide band pre-amplifier with a separate power supply to provide isolation from Electro-
Magnetic Interference. It has six inputs plus one additional input for an optional plug-in module. Currently a
high quality phono module is in the final stages of development, with other modules under consideration.
Provision has been made to allow the Cadenza to be used with a surround processor. The output level is
controlled by a precision 59 step attenuator. This is an improved version of the attenuator used on Cello
products and gives better sound quality and more consistent operation.
Brief Specifications:
Inputs: 4 x Unbalanced
1 x Balanced
1 x Fischer
1 x Optional input card
Outputs :
1 x Unbalanced
2 x Balanced
1 x Fischer
1 x Tape output on unbalanced connectors
Front Panel Controls: Input selector
Separate left and right channel gain controls
Output level control
Frequency Response: 20Hz to 20kHz ± 0.1dB
IMD: Less than 0.005% @ 1V input
THD: Less than 0.01% @ 20kHz 1v input
Noise: -95dB
Dimensions:
Pre-amplifier: 44.7cm W x 9.1cm H x 40.6cm D
PSU: 22.3cm W x 9.1cm H x 40.6cm D
Weights:
Pre-amplifier: 7.3 kg
PSU: 9.1kg
The Symphony is a 250W stereo power amplifier with an integral power supply. Like the Bravo, the
Symphony power supply also uses an Inductor Input System. This avoids the high peak current demands
that would be placed on the mains supply by a conventional power supply design and therefore minimises
inter-modulation distortion on the power supply rails and ground returns. It is also relatively unaffected by
power supply voltage variations compared to conventional designs. An additional benefit of this technique is
that it reduces the stress on the key power supply components, leading to higher reliability and longer life.
Viola amplifiers are designed to ensure highly controlled behaviour under all conditions of use. Particular
care has been paid to the overload conditions that are often encountered under normal use. Soft clipping
circuitry is used to limit sonic degradation if the amplifier is overdriven (voltage overload). Bandwidth control
results in nearly identical small signal and large signal frequency responses. This approach avoids slew rate
limiting (frequency overload). In order to ensure accuracy in the time domain, the bandwidth control has a flat
group delay characteristic. This implies a linear phase verses frequency relationship and means that all
signals pass through the amplifier with the same amount of delay. In plain English the output signal looks
exactly like the input signal, only bigger.
Great efforts have been made to minimise distortion at lower frequencies, because the majority of energy is
encountered at these frequencies in most music. Obtaining low distortion without the use of large amounts of
corrective feedback requires the use of more output devices and more refined lower level stages.
Brief Specifications:
Output Power: 250W per channel into 8Ω
500W per channel into 4Ω
Inputs: 1 x Balanced
1 x Fischer
Outputs: 2 pairs of WBT terminals per channel
Frequency Response: 20Hz to 20kHz ± 0.15dB
10Hz to 100kHz, -3dB
Power Bandwidth: 5Hz to 100kHz
THD: Less than 0.1% @ 20kHz and 250W
