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.
s. In it, a set of batteries or battery provides the reference voltage for the output. The...
This circuit converts BCD inputs to analog voltages. The operational amplifier must be powered...
This circuit is from a 1992 documentation, but the components used can still be easily assembled. The...