We found this circuit in the November 1992 issue of Radio Electronics magazine. The circuit has two integrated circuits, one of which is a preamplifier stage. The power supply must be dual.
This filter is suggested by Motorola's Linear Interface ICs of 1993. This same configuration...
This two-microphone amplifier was found in a April 1961 Radio Electronics Magazine. The circuit is...
We found this circuit in a November 1970 Radio Electronics. It uses a PUT or programmable...