KORG PA4X 76 - Manual (Page 738)

734| Controllers
2 Use the Velocity Curve parameter to set the sensitivity of the keyboard to
your playing strength.
Velocity Curve Meaning
Fixed No dynamic control available. Dynamic values are fixed, as in classic
organs. When this option is chosen, you can set the fixed velocity
value.
Soft1 … Hard3 Curves, from the lightest one to the hardest one.
3 Use the Aftertouch Curve parameter to set the sensitivity of the keyboard
to the pressure you apply after playing a key.
a.touch Curve Meaning
Soft1 … Hard3 Curves, from the lightest one to the hardest one.
Off The aftertouch is turned off.