Akai S3000XL User Manual page 106

EDIT PROGRAM - SINGLE
Once the basic envelope has been set up, these other factors can be used to affect the
speed of the envelope.
Page 100
This is variable from +50 to -50, and determines the
amount by which the attack speed will be changed
depending on the Note On velocity. A positive value will
increase the attack time if the key is pressed fast, while a
negative value will slow down the attack rate if the key is
pressed fast. Setting a positive value here is the most
commonly used way of using this parameter and is useful
for imitating the characteristics of some acoustic
instruments (for instance, most wind instruments have a
faster attack rate when played loudly).
This is used to vary the release rate relative to the Note On
velocity value (+50 to -50). Again, a positive value will
increase the release rate relative to the Note On velocity,
and a negative value will shorten the release time.
The MIDI specification allows for Note Off velocity as well
as Note On velocity. Though some keyboards do not
accept or transmit this, assuming a mean value of 64, all
AKAI keyboards provide a full implementation of this
function. The speed with which the key is released can be
used here to affect the release rate (positive values mean
that a fast release lengthens the release rate, and vice
versa).
This allows you to control the amount by which the key
position affects the decay and release rates. Setting this to
a negative value means that the higher the note played on
the keyboard, the shorter the decay and release times
(similar to most acoustic instruments). Setting this
parameter to a positive value will reverse this effect.
This can be set to ON or OFF. When ON, the attack
portion of the envelope will be held until looping begins,
and when OFF, the envelope will continue along the set
values, regardless of loop settings. I.e:
Attack HOLD: ON
Attack
Loop Loop
Decay
Sustain
S3000XL Operator's Manual