Korg PS Polyphonic Synthesizer PS-3100
Owners Manual

(1) CONTROL SECTION: Operation and principles ^

1 - 5 Amplitude Modulator (AM)

Amplitude Modulator module

Figure 10 - Amplitude Modulator

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

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.)

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