Dave Smith Instruments Sequential PROPHET X, User Manual, Page: 54 / 172

42 Amplifier Envelope Dave Smith Instruments
Amplifier Envelope
After passing through the filters, a synthesized sound goes into an
amplifier or VCA , which controls its overall volume. The amplifier has a
dedicated, 5-stage envelope generator (ADSR plus delay).
The Amplifier Envelope is used to shape the volume characteristics of
a sound over time by giving you control over its attack, decay, sustain,
and release stages. Along with the filter envelope, this is one of the most
important factors in designing a sound.
Without a volume envelope, the volume of a sound wouldn’t change
over the duration of a note. It would begin immediately, remain at its full
volume for the duration of the note, then end immediately when the note
was released. Again, that’s not very interesting sonically and it’s not typi-
cally how instruments behave in the real world.
To give you a real-world example, the main difference between the sound
of the wind and the sound of a snare drum is that they have very different
volume envelopes. Otherwise, they are essentially both white noise.
Wind has a relatively slow attack, a long sustain, and a long decay and
release. A snare drum has a sharp attack, no sustain, and very little decay
or release. But again, they are both fundamentally white noise.
Amplifier Envelope