Found in an Electronics World of 1966 this circuit can be made with current power transistors. It causes colored lamps to flash to the rhythm of the audio signal applied to the input.
The circuit presented may use any general purpose transistor. The indicator is an LED and...
The circuit shown uses the LM324, but can be implemented with other operational ones. The source...
This circuit was obtained from an English publication from the 70's. The circuit is still current for...