This circuit was found in a 90s Radio Electronics. It is intended to amplify the sound channel of analog televisions of the time. The integrated circuit used is uncommon today.
In the diagram from the November 1999 Electronics Now magazine we have the way to improve both the...
This simple circuit was found in a 2001 documentation. With each touch of CH1, a 4017 output...
With the use of a microphone and an amplifier stage, this circuit does not require connection to...