LinPlug SaxLab - Manual (Page 16)

Sustain level. Setting the D (Decay) slider to higher values increases the time
taken for the sound’s amplitude to move from full volume to the sustain level.
R (Release): The R (Release) control is used to set the length of time that the
amplitude envelope takes to move from the current level to silence after the
key is released. Setting the R (Release) slider to higher values increases the
time taken for the sound’s amplitude to decrease to zero.
Note: The Sustain level is is reached at the end of the Decay phase and is
fixed at 50% of the maximum level (that is reached at the end of the Attack
phase).
The time range of A and R are actually useful only for special effects, as a real
sax doesn't have a meaningful release time and the attack time is controlled in
realtime by the player. So for a good emulation these parameters should stay
close to zero (bottom of the fader), but not zero. For a slow attack the attack
time (or the main volume) should be controlled by a MIDI controller (see
section ECS).
SaxLab 2.1.6 User Manual Page 16