For an 8 ohm load, this Motorola circuit was found in a 1968 documentation. The transistors are of the time and the power supply must be symmetrical.
Found in old documentation, this circuit uses components that are still common on the market. The...
This circuit is from the American magazine that no longer exists Science & Electronics,...
This circuit was found in a 1969 US documentation. It provides a signal that can be externally...