The diagram shows a tone control with the LM381 IC. The circuit is from a Radio Electronics from February 1990. The power supply is single.
This circuit works in the opposite form to the previous one and drives a relay as a load. The...
This circuit was originally published in a 1966 book from Spain. The circuit uses a...
This circuit was found in a Modern Electronics from 1990. It activates an old electromechanical pulse counter,...