This 80's circuit uses a germanium transistor like the AC121. The circuit has an output transformer of the type found on many transistor radios of the time.
This circuit uses an optical coupler called Raystor created by Raytheon in the 1960s. The circuit...
This filter, found in an old manual, has characteristics of reduced overvoltage given by the graph...
The purpose of this circuit is to provide a few watts of power to a heavy speaker with good sound...