This circuit was found in the January 1999 issue of Electronics Now magazine. The circuit uses an integrated circuit from the period and has earphone listening.
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...