This circuit for audio signals was found in the March 1990 Radio Electronics magazine. The circuit uses a unusual optocoupler that can be replaced with an equivalent one.
This circuit is just a curiosity found in a 1990 documentation, since the integrated circuit used...
This circuit was obtained in a 1964 Electronic Design. The circuit uses components from that time,...
Found in a 1992 book, this circuit is intended for operation with audio signals. Equivalent...