The integrated circuit used is uncommon today. We found this configuration in Motorola's 1990 Linear Databook. The triac can be any of the TIC series.
This circuit for audio signals was found in the March 1990 Radio Electronics magazine. The circuit...
The operational amplifiers used in this circuit are old. The circuit is from documentation of the 70's, but...
This circuit was obtained in the publication 101 Electronics Projects of 1979. The circuit can be...