Alesis S4 Plus Reference Manual page 71

Chapter 6: Editing Programs
Decay & Sustain (00 to 99)
As soon as the attack portion of the envelope finishes (when the level reaches
maximum), the envelope will decay (decrease in level). The level it reaches is set by
the Sustain control; how long it takes to get there is set by the Decay control. In the
special case where the Sustain level is all the way up (99), then there is no decrease
and the Decay time segment is bypassed. Whatever level the sustain is set to is the
level that the decay section of the envelope will head for. Depending on the setting of
the Sustain Decay control (see below), the envelope will either hold at the sustain
level until you release the note on the keyboard, or decay to 0 at the Sustain Decay
rate (which is on page 2 of the envelope). You can create a long "plateau" at the start
of a note by setting the Sustain to 98 and the Decay to 99. This will cause the
envelope to take the maximum amount of time to get from peak level to a level of 98,
before the Sustain Release portion of the envelope begins.
Release (00 to 99, Hold)
Eventually, you will let go of the note that you've been holding (either by releasing the
note on the keyboard, or releasing the sustain pedal if it was pressed). It is at this point
that the Release portion of the envelope takes effect. The Release is the time that the
envelope takes to get from its current level back down to nothing. Setting the Release
time to 99 will take the envelope a very long time to reach zero level.
The Pitch Envelope is unique from the other two envelopes in that its Release time
can be set above 99. When this is done, the value in the display will read "Hold". This
indicates that the pitch envelope will remain where it is even after the note is
released. This is important when you want the pitch effect to continue even after
releasing the key. Example: If the PENV is bending a note up, and you don't want the
pitch to fall when you release the key, set the Release parameter to "Hold".
Pitch Envelope (Page 2)
Delay (00 to 99, Hold)
This is the amount of time that the envelope will wait before doing anything; very
useful if you want to affect one element of a sound sometime after the sound starts.
When the Delay is set to 0, the envelope attacks right away, without any delay. Play
some notes while turning up the delay and see that the time between playing the note
and hearing the effect of the Pitch Envelope gets progressively longer as the Delay
control is turned up.
If the Delay is set above 99, the display will read "Hold". This indicates that the Delay
stage of the envelope will wait indefinitely until the key is released before continuing
on to the remaining envelope stages (Attack, Decay, etc.). This requires that the Pitch
Envelope's Trigger parameter (see next page) is set to "Freerun". However, when
the Delay is set to "Hold", "Freerun" mode is forced on regardless of the Trigger
parameter's setting.
Sustain Decay (00 to 99)
This is the amount of time that the envelope will take during the sustain stage to bring
the level down to 0. If this is set to 99, the envelope will remain at the Sustain level
until the note is released. When set to 0, the envelope's level will immediately jump
down to 0 upon reaching the sustain stage.
Trigger (Normal, Freerun, Reset, Reset-Freerun)
The Trigger mode determines how the envelope will function. You may select either
Freerun or Reset, or both (Reset-Freerun) or neither (Normal). When set to Normal,
the envelope will always start at its current level (i.e., if another note had been played
70 S4 Plus Reference Manual