FM Tone Generation
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Appendix
(3) Feedback Level
As we saw earlier, feedback is a function in which a modulator's output is connected to its own input, so that
it modulates itself. Increasing the feedback level increases the harmonic content of the sound, making it
brighter and complex. Keep in mind that the total effect also depends on the output level of the feedback-
applied operator; if that operator's output level is set to “0,” feedback level will have no affect on the sound.
(4) EG (Envelope Generator)
The EG (Envelope Generator) parameters allow you to shape the sound of the voice. In other words, these
determine how the level of the voice changes over time, from when a key on the keyboard is played until it is
released and the sound dies out.
The EG parameters let you reproduce the sound of acoustic instruments, and their natural patterns of attack,
sustain and decay. For example, the sound of a piano has a very sharp attack and a moderately long sustain:
The sound gets loud the instant a key is played, and gradually fades away as the key is held. The tone or tim-
bre of the sound also changes in time, with the sound starting out very bright and gradually growing warmer
and softer (as the harmonics start to fade).
Since each operator has its own EG, the DX200 gives you comprehensive and dynamic control over both the
volume and timbre of the voice, letting you accurately reproduce these natural acoustic effects. The carrier
EGs affect the volume of the sound over time, while the modulator EGs affect the timbre.
A
B
A
B
Frequency
ratio 1:2
Frequency
ratio 1:1
Sawtooth wave Rectangular wave
Modulator
Carrier