This circuit is based on a Siemens S566B integrated circuit. The circuit is from a Radio Electronics Experimenter and also has a digital control input.
In the figure we have the adapter circuit for connecting a headphone to the output of a stereo...
Found in the June 1972 issue of Radio Electronics magazine, this circuit generates signals that...
The output of this circuit must be connected to the input of an audio amplifier. The microphone is a small...