This circuit allows the use of an electret microphone with a 1.5 V source. We found it in the Encyclopedia of Electronic Circuits volume 5 from 1995.
Found in an older Radio Electronics, this circuit generates signals that can be used with regular...
This circuit was obtained in a manual of operational amplifiers of 1973. The circuit uses...
This is a battery powered 3W power amplifier using germanium transistors. The circuit is from an...