This circuit was found in a 1980s Intersil documentation. The integrated circuit used is not common today. The power supply must be symmetrical.
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...