(1) CONTROL SECTION: Operation and principles ^
1 - 5 Amplitude Modulator (AM)
Figure 10 - Amplitude Modulator
Amplitude modulation is a method of varying the amplitude of one AC signal in proportion to the fluctuations in a second signal. The tremolo effect of most electronic instrutnents is obtained by modulating the sound signal with a second low frequency signal by means of a VCA.
When the AM knob is set to "5", modulation is 100% and the result is a tremolo effect. If you turn the AM knob up to "10", modulation is 200% giving the same effect as a ring modulator. The availability of both these effects gives you additional freedom in sound synthesis.
Figure 11 - Using the AM effect
Using the AM effect with the PS-3100
Set the AM knob to "10", turn on the
switch below the knob, set the MG-1 waveform for TRI (triangle), and the Frequency
knob to "0". (All other controls should be at normal setting.) Then play a key
and slowly turn up the Frequency knob to "10". Note how the sound changes first
into a tremolo-like effect and then into a metallic sound with the ring modulator
effect. (Try using different waveforms both in the singal generator section
and in MC-1. Note the differences in tone color and effect.)