JPS54151019A - Sound source circuit of electronic musical instruments - Google Patents

Abstract

PURPOSE: To produce good vibrato tone with a simple and small constitution by disturbing the phase locked loop locked at the reference signal frequency of scale by low frequencies.

CONSTITUTION: The reference signal of the scale which a high frequency generating circuit 31 generates is locked of its frequency by the phase locked loop circuit formed by a phase comparator 33, an LPF 34, a mixing circuit 35, a frequency converting circuit 36 feedfack connected to the circuit 35, etc. When a switch SW₃ is closed, the low frequency signals from a low frequency generating circuits 32 of fifferent oscillation frequencies are applied to the mixer 35 by variable resistors VR 31, 32 and the scale signal of the specified frequency having been locked is disturbed according to the low frequencies, thence the vibrato tone of the selected scale is produced from a musical tone forming circuit 39 by way of the mixing circuit 38. If the similar circuits are parallel provided for lower keyboard, the vibrato tone of less errors by the upper and lower keyboard is formed.

COPYRIGHT: (C)1979,JPO&Japio