Found in a 1968 American documentation, this circuit uses an operational amplifier that is uncommon today. The feed must be symmetrical. The gain is 40 dB.
This old fashioned amplifier can source some watts to a low impedance loudspeaker. The circuit...
This circuit is from a Radio Electronics from September 1969. The integrated circuit used is one...
This CMOS circuit is re-triggerable. It was found in the April 1988 issue of Radio Electronics...