This common circuit using operational amplifiers was found in the 1993 issue of Radio Electronics Special Projects. The circuit is sandwiched between the pickup and the amplifier input.
This circuit has a power stage with transistors that allows to obtain a current greater than that...
This circuit converts signals from the shortwave band to the 118 to 130 MHz VHF band used in...
We found this circuit in an old publication dealing with operational amplifiers. The circuit uses...