Skip to product information
1 of 4

Viola Labs

Viola Labs Concerto

Regular price $22,500.00 USD
Regular price Sale price $22,500.00 USD
Sale Sold out
Shipping calculated at checkout.

Housed in the same size billet Aluminium chassis as the Crescendo, the Concerto delivers 125W into 8 ohms and 225W into 4ohms. Like all Viola power amplifiers the Concerto uses a choke input power supply. This reduces peak charging currents that are prevalent in capacitor input supplies. This minimizes intermodulation distortion on the power supply rails on ground returns.


The Concerto can be connected to the Crescendo preamplifier via the CAN (Controller Area Network) connector. When this is done Concerto status information including temperature and line voltage are transmitted to the Wi-Fi remote application. This also provides synchronization of the color displays and standby modes.

Audio Design

The Concerto is a Class AB biased push-pull amplifier design.

The Concerto incorporates Motorola Thermal Track™ into the bias network. This provides fast thermal feedback information without the thermal lag of other bias topologies.

A center chassis Venturi style heat sink provides cooling for the amplifier.

Connections to loudspeakers are provided by a pair of WTB nexgen™ connectors per channel.

Output Power Stereo Mode
125W into 8 ohms
20Hz to 20kHz, THD < 0.25%
225W into 4 ohms
20Hz to 20 kHz, THD < 0.5%
Bridge Mode
450W into 8 ohms
650W into 4 ohms
All power figures quoted are continuous average power
Inputs 2 x XLR
Outputs 1 pair of WBT terminals
Frequency Response 10Hz to 20kHz ± 0.15dB at 1W into 8 ohms
5Hz to 100kHz, -3dB at 1W into 8ohms
Power Bandwidth 5Hz to 100 kHz 125W, C weighted
Tape Output 600 Ohms
Dimensions 17.5″ W x 3.5″ H x 15″ D
44.5cm W x 9.8cm H x 38.1 cm D
Weight 35 lbs. (15.9kg)



Products of Viola Audio Labs are warranted to be free of defects is used under normal conditions for a period of five years from the date of manufacture.

All specifications are subject to change without notice.