Suggested by General Electric in a 1965 publication this circuit uses a light bulb. Can be changed to use LED and capacitor can be 22 uF.
Published in Popular Electronics with the curious name of Obnoxious Noisemaker, this 1968 circuit...
This preamplifier circuit for turntable cartridges was found in the March 1994 issue of...
E) This circuit was found in documentation from the 1980s. The integrated circuit used is not very...