Piezoelectric Bridge-Type Pickup for a Stringed Musical Instrument

This European patent application by Kaman Music Corporation describes a bridge-type piezoelectric pickup for guitars and other stringed instruments featuring a flexible circuit board carrying pairs of transversely polarized piezoelectric crystals for each string. Each string has two closely spaced crystals supporting a common saddle, allowing differentiation between in-plane and longitudinal string vibrations through voltage bucking circuitry. The design incorporates active semiconductor operational amplifier circuits near each crystal set to provide high impedance input and low impedance output, reducing cross-talk between strings and improving frequency response.