KR Audio VA910 Amplifier

The Circletron circuit is a specific topology that allows for a balanced, symmetrical output, which helps the amplifier maintain stability and low distortion. By using floating cathode technology, it enables the KR 842vhd tubes to perform with greater linearity and efficiency than traditional designs.

The VA910 features an input sensitivity of 1V RMS into 100 kOhms, making it compatible with most high-quality preamplifiers. Because it uses RCA inputs, you will need a preamplifier with single-ended outputs to connect to the units.

Each unit weighs approximately 40 kg and measures 38.5 x 28 x 55 cm, so you will need a very sturdy, dedicated equipment stand. Because these are high-power Class A tube amplifiers, they generate significant heat and require ample open space around them for proper airflow.

The VA910 is designed with output taps for 4 and 8 Ohm speakers. While it is robust, ensure your speakers do not dip significantly below 4 Ohms to maintain the best performance and avoid stressing the output tubes.

Zero-feedback architecture avoids the use of global negative feedback loops, which can sometimes introduce phase shifts or timing errors in the signal. This design approach is intended to preserve the natural harmonic structure and transient speed of the music.

Yes, the tubes are replaceable, but because this amplifier uses a large array of eight tubes per mono-block, they should be replaced as a matched set to ensure consistent performance. We recommend consulting with a professional or the manufacturer when it is time for a retube to ensure proper biasing.