This circuit has a gain of 6 dB for low frequencies from 85 Hz and can be used in a mini subwoofer. The circuit is from a Radio Electronics from March 1990.
This traditional 555 touch bistable configuration has already been explored in projects on this...
In the figure we have a circuit that allows us to obtain a variable voltage of approximately 0.5 to 25 V...
This circuit was obtained in an old publication of 1978. The integrated circuit is the critical...