Yamaha AN1x Owner's Manual page 69

Sustain
The Sustain setting determines the level of sustain of the
AEG, which is the level at which the volume will be
maintained for as long as a key is held. Turning the
knob to the right increases the Sustain level.
Settings: 0 ~ 127
Release
The Release setting determines the release time of the
AEG, which is the time it takes for the signal to reach a
level of "0" after a key is released (key off). Turning the
knob to the right increases the Release time.
Settings: 0 ~ 127
Level
Sustain
Attack Decay
Key on
Time
Release
Key off
69
Feedback
The Feedback setting determines the level of feedback
output from the VCA and "fed back" into the input of
the mixer, causing the signal to build up in amplitude
according to the level you set. Turning the knob to the
right increases the Feedback level, resulting in a fatter
sound.
VCO Mixer HPF
Feedback
Settings: 0 ~ 127
Feedback should be applied slowly and with caution. Too much feedback can
create extremely high frequencies, potentially resulting in damage to your
speakers.
Too much feedback may drastically change the VCF characteristics.
Volume
The Volume setting determines the overall output level
from the VCA before the signal passes to the Effect
block. Turning the knob to the right increases Volume
level.
Settings: 0 ~ 127
VCF VCA OUT