Sound sustaining device for musical instruments

Claim 1

A sustaining device for sustaining musical sounds produced by a stringed musical instrument which includes at least one electromagnetic pick-up associated with the strings of the musical instrument for generating electrical signals having frequencies corresponding to the frequencies of vibrations of the strings of the musical instrument, the sustaining device comprising amplifying means connected to said electromagnetic pick-up for amplifying said electrical signals generated by said electromagnetic pick-up; and a loudspeaker serving as an output transducer connected to said amplifying means for converting said amplified electrical signals into mechanical vibrations and for imparting movements to said strings to correspond to the magnified electrical signals, said loudspeaker being resiliently mounted on the musical instrument to minimize direct acoustic coupling between said loudspeaker and said electromagnetic pick-up and arranged proximate to the strings of the musical instrument, said amplifying means, said strings, said electromagnetic pick-up and said loudspeaker together forming a self-contained regenerative system for sustaining a musical sound substantially independently of the volume of the musical sounds produced by the stringed musical instrument; acoustic shielding means provided for acoustically shielding said loudspeaker from said electromagnetic pick-up to minimize direct acoustic coupling between the same; and electromagnetic shielding means for electromagnetically shielding said loudspeaker from said electromagnetic pick-up to minimize direct electromagnetic coupling between the same, whereby mechanical, electromagnetic and acoustical feedback takes place primarily only through the vibrating strings of the instrument to thereby provide controlled sustain of the musical notes.