This percussion circuit was found in an Electronics World of 1968. The transistor may be general purpose and the power supplied at 12 V. The signal must be applied to an amplifier.
In the figure we have the simple way to obtain a digital inverter using a general-purpose...
This circuit works with only 1.5 V and can be powered by a solar panel. The circuit is from 1991....
This circuit was found in a 1969 EEE. The circuit uses transistors from the era that can be...