This circuit was found in American documentation from the 1980s. The integrated circuit used is a voltage comparator of the time. Modern equivalents can be tested.
We found this electronic organ circuit in a 1987 documentation. The circuit should be powered by...
Only incandescent lamp can be used in this circuit. The SCR must be mounted on a heatsink and...
In this project, from a Japanese magazine of 1973, only one channel of a stereo amplifier of 20 W...