This circuit was found in a 1964 documentation. It shows how to achieve automatic gain control for an oscillator. The transistors are of the time and the circuit controls signals from 2.6 to 3.1 kHz.
This circuit that simulates the sound of a drum is part of an article published in the Radio...
This circuit was obtained from an Application Note from Linear Technology that manufactures the used...
This is a well-known RC oscillator configuration using a 741 operational amplifier. The circuit is from...