This circuit generates damped sounds imitating a drum or other percussion instrument with alteration of the double T components. We find it in an old American documentation.
This small earphone amplifier with germanium transistors was obtained in a Japanese publication from...
The sensor for this circuit is a phototransistor. We found it in the April 1971 issue of Radio...
Found in a 90s Popular Electronics, this circuit allows to select the operating ranges between...