This 2-tube amplifier was found in a Japanese publication of 1964. The circuit has excellent sound quality. The power supply is not given and must provide a voltage of 300 V.
Found in documentation from the 1970s, this circuit for resistive loads uses a trigger...
This simple receiver for listening on the phone was obtained in a 1960 documentation. The circuit is...
This circuit was found in the 1989 Radio Electronics Experimenter edition. The circuit has the...