SOUND SOURCE APPARATUS OF ELECTRONIC MUSICAL INSTRUMENTS

摘要

PURPOSE:To modulate sound source signals effectively even if the amplitude of the variable frequency modulating waves oscillating the sound source signals become large by providing a circuit for folding the signal from an adder. CONSTITUTION:The apparatus is so constituted that one of pitch signals Vref accompanied with key operations is added to an adder 13, another to a variable frequency oscillator VCO 12 via level controller 16, that the output signal thereof is added to the signals Vref in the adder 13 and is then supplied to a VCO 14 via folding circuit 17 and that sound source signals are oscillated by this VCO 14. Hence, the signal components below zero V of the output signal of the adder 13 are folded and appear on the positive side and therefore the musical tone formation may be effectively performed even if the amplitude of the modulation signal for the sound source signals generated by the VCO 14 is large.