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 was obtained from an old English book. Transistors are types of the time....
Found in 1967 Raytheon documentation, this circuit uses a company coupler consisting of a lamp and...
The basis of this circuit is the TL032 from Texas Instruments. The circuit converts an input in...