Suggested by General Electric in a 1968 documentation this integrated amplifier uses a component of the era, the PA237. The circuit runs on 24 V and excites a 16-ohm speaker.
This circuit was obtained from a 1966 documentation. The transistors are of the time. The circuit...
This amplifier circuit with a low power MOSFET was found in Popular Electronics from the 90s. The...
This circuit was found in American documentation from the 1960s. The operational amplifier is from that...