This 6-tube two-channel amplifier was found in an American documentation from 1947. The circuit is two-channel with a separation of bass and treble.
Found in a manual of integrated circuits from the 90s, this circuit makes use of that time...
This circuit uses one UJT (Unijunction Transistor) to produce three different tones in a...
This circuit was found in an American 1980s documentation. The integrated circuit used is uncommon...