We found this circuit in the Linear Applications Handbook by National Semiconductor. The circuit is from 1994, but it can be made with more modern equivalent components.
This circuit was found in a 1966 American publication. The critical component is the tunnel diode. ...
This simple audio generator with the 741 was found in a 90sTexas Instruments. The circuit...
This circuit was found in a 1991’s PE Hobbyst Handbook. The circuit is based on altering the sound...