This midrange filter for sound systems was found in the May 1988 issue of Radio Electronics magazine. The circuit is based on a dual amplifier that must be powered by a symmetrical source.
This Philips commercial circuit is from the 90's documentation. The integrated circuit must be...
We found this circuit in the September 1971 issue of Radio Electronics magazine. The sensor is an...
This circuit is from a Hands-On Electronics from 1987, but it can still be easily assembled, as...