Using a 709 integrated circuit this circuit was found in the June 1972 issue of Radio Electronics magazine. More modern operational equivalents can be used. The power supply is symmetrical.
This circuit was taken from recent English documentation. The circuit uses a 500 uA microammeter as an...
Found in Popular Electronics from the 90s, this circuit uses a reed switch on the rails as a...
This filter for scratch and rumble noises that occur on turntables was found in the February 1995...