'mehrstimmiges electric piano and method of producing the tones

摘要

An electric piano has a complete player actuated piano voice of which harmonics are basically controlled by a tuning fork that is struck by the piano key. The piano is also provided with an electronically generated voice of which harmonics are electronically generated. To better enable the two voices to be played simultaneously by striking a single piano key, the amplitude envelope of the electromechanically generated piano voice is imposed upon the electronically generated voice which is gated and amplitude modulated so as to be heard in precise synchronization with a piano note produced by the instrument player. Linearity of modulation is extended to low piano voice amplitudes by use of modulating and gating diodes in oppositely poled feedback paths of an operational amplifier.