Viola Labs Bravo

The Viola Bravo stereo power amplifier has been designed to the last word in fidelity, musicality and dynamics. It will effortlessly deliver large amounts of power while preserving the delicate nuances in the music signal.

Bravo Power Supply

The heart of power amplifier is its power supply. The Bravos use choke input filter type power supply with a generously rated 2kVA mains transformer. Four 80,000 μF filter capacitors are located in the power amplifier chassis, providing optimum decoupling for the audio power stages.

The Bravo’s power supply design completely avoids the generation of the high frequency noise that occurs with switch mode power supplies. It also places less stress on the power supply components, leading to higher reliability and longer life. An additional benefits is that high peak ripple currents are virtually eliminated, minimizing intermodulation distortion on the power supply rails and grounds returns. This enhances sound quality by reducing noise and distortion levels.

Audio Design

The signal path in the Bravo is fully balanced throughout the voltage gain stages. This is essential to achieve the maximum immunity from external sources of noise.

Soft chipping circuitry limits sonic degradation should the amplifier be overdriven. Bandwidth control results in nearly identical small signal and large signal frequency responses and avoids slew rate limiting. To ensure accuracy in the time domain, the bandwidth control has a flat group delay characteristic. Great efforts have been made to minimize distortion at lower frequencies, because the majority of energy is encountered at these frequencies in most music.

To improve transparency and the resolution of low level signals, the output stage operates with a relative high quiescent current. Heavy oxygen free copper bus bars enhance the efficiency of power distribution within the amplifier.

Film capacitors are used on the individual circuit boards in the unit to provide the high frequency bypass for the power supply and ensure that all sections of the amplifier see a uniformly low power supply impedance. This is key to the Bravo’s ability to deliver massive amounts of power while preserving all the subtle aspects of the music signal.