The ADC801 is not an easy component to obtain today, but the configuration is worth reference. The circuit is from National Semiconductor's Linear Applications Handbook.
This 70 kHz oscillator is used to erase tapes in pre-recording. The circuit is from 1968 General...
This circuit acts as a VU-meter when connected at the output of any audio amplifier, triggering a...
When the voltage exceeds the value given by the zener, this circuit from a 1990 documentation...