This circuit was found in an old American publication. The transformer is the type of output found in old transistor radios. The transducer is crystal headphone.
This circuit was found in documentation two years 80. Transistors can be modern equivalents. Or...
This circuit, very critical due to the frequency at which it operates, was found in an American...
This stereo circuit with the 2002 integrated circuit. The power is 6 W per channel with 16 V of...