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.
The note sequence for this circuit is achieved through integrated circuits controlled by the 555....
When a voice signal enters this circuit, the volume of the music being played automatically...
We found this configuration in a Radio Shack documentation from 1977. Here we have the way to...