Found in a Raytheon transistor manual from the 1950s, this circuit uses one of the first commercially available transistors, the CK722. The circuit is for using a small speaker as a microphone.
This 4-transistor signal tracer or follower was found in Radio Electronics magazine from May 1960....
This sound effect circuit uses only one integrated. We found it in a 90's EDN. The effects can be...
This is one of many power control or dimmer configurations that we have found on this site and in...