We introduce our first integrated dual-mono vacuum tubes amplifier based on a modernized Williamson circuit. It is a 27 Watt per channel Push-Pull, operating in ultra-linear mode, optionally switchable to triode mode.
Soviet triodes 6N8S are used as steering vacuum tubes at the pre-amplifier stage. The power stage operates on excellent GU-50 transmitter vacuum tubes, Soviet-made for the military in the 1960s (NOS).
In order to minimize distortion, the power supply is separated from the amplifying section by placing it in a completely separate, screened case.
While designing the circuit we managed to achieve identical topography of the left and right channels, which resulted in a fully symmetrical signal path.
It should be noted that loudness control does not employ a common potentiometer, but a 64-step attenuator (based on relay switches) by Khozmo Acoustic, which minimizes signal inequalities in both channels of the amplifier. The circuit employs a small number of condensers in the signal path, which also improves sound quality.