| 摘要 |
PURPOSE:To obtain desired distortion effect with simple circuit constitution. CONSTITUTION:In LFO mode, MS=0 and a selector 5 selects the count output of a counter 6. The count direction is inverted with a constant period by a change of a clock phi1. Sine waveforms having 0-1/4 and 1/4-1/2 cycles are read out of a ROM 7 alternately with the count output. The sine waveforms having 0-1/2 cycles are converted into sine waveforms having 1/2-1 cycles by an inverting circuit 8 and a half-adder 9 and selected alternately by a selector 10 and read out to read the sine waveform having one cycle in order. In distortion mode, the selector 5 supplies the amplitude absolute value of the waveform signal to the ROM 7, a corresponding waveform value is outputted and supplied to a selector 10 while having a waveform value which is shifted by a 1/2 cycle, and one waveform value is selected and outputted according to the state of the MSB of an input waveform signal. |
