This control for bass, midrange, and treble was found in the March 1995 issue of Electronics Now magazine. The circuit requires a dual power supply.
In the figure we have an application of ON Semiconductor's own semiconductor manual from the 80's....
This circuit can be used in the car to convert the 12 V from the battery in 6 or 9 V up to 2 A....
This circuit makes use of an unusual component today, a LASCR. It is a light-activated SCR. The...