Compensation circuit for piezoelectric pickup

摘要

The signal from a piezo-electric transducer in an electro-acoustic guitar is modified by a variable depth notch filter. The notch filter includes two paths between an input and a summation circuit. The signals in the two paths are 180 DEG out of phase and one of the paths includes a bandpass filter. The notch is located at approximately 5 khz. The depth of the notch depends upon either the broadband amplitude or the narrowband amplitude of the signal from the transducer and the depth of the notch is controlled using either feedback or feedforward control.