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 experimental amplifier was found in the 1960 Mullard transistor reference manual. The...
This circuit from Motorola is from 1968, appearing elsewhere on this site. The transistors admit...
This circuit triggers the LED when the monitored battery voltage drops below 9 V for 12 V...