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 configuration is from the 70s, having been found in an American documentation. The...
We found this circuit in a European documentation from the 90's, but the circuit is current, as it...
This circuit activates a relay when the phone rings allowing the control of a warning lamp or even...