This circuit, to add the ambience effect, was suggested by National Semiconductor in documentation from the 90s. The amplifier needs an appropriate power source.
These reset circuits when the power is turned on were found in an 80's EDN. The circuit also...
This circuit was found in a Philips documentation from 1970. The components are of the time,...
The LM2904 is not very common today, but common comparators and operationals can be used in the...