The PA222 integrated circuit used in this project from an American 1967 documentation is not common today. The circuit can deliver higher power with lower fidelity.
This circuit was found in Motorola documentation from the 1980s. PUTs are not common components...
This low distortion circuit was found in a 1964 Electronic Design. The transistor admits...
This circuit is based on an uncommon Texas component today, as found in an American 1980s...