This circuit was found in documentation from the 90s. The operational amplifier is NE5514, which is uncommon today. The configuration can be adapted to use modern components.
This circuit was obtained from a 1967 General Electric documentation. The circuit makes use of...
This configuration uses the 4 gates of a 7401 integrated circuit. The capacitors determine the...
This filter can be used to eliminate hum in sound equipment. Operational amplifiers can be 741 and...