The sound of drums can be obtained with these two touch-triggered double-T oscillators. The circuit is from a Radio Electronics Special projects from 1993.
With this converter it is possible to tune the signals of the 15 MHz WWV.in AM receiver. WWV is...
This negative voltage source was found in a Popular Electronics from the 90's. The transformer has 120V...
This circuit is from the Audio Handbook of the National Semiconductor of 1977. Its purpose is to...