Amplifier with different output (CB9057E)

This circuit was found in a 70s National Semiconductor manual. It has a different output way for coupling to the speaker.

2-Transistor Amplifier (CB22508S)
This 1950's circuit used one of the first commercial transistors and had two stages for audio...
Audio compressor (CB22154E)
Using integrated circuits from the time, we found this audio compressor in an English publication from...
Micro Radio (CB18167E)
This is an experimental crystal radio that uses no power source. The antenna must be very long (at...