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.
With changes, this circuit from a documentation of the 70s, can be adapted to use more modern...
Found in a 1968 EEE, this switch controls a high-power load from an audio signal. The current is...
In this circuit the gain decreases as the input signal intensity increases. The circuit is from a...