KORG PA4X 76 - Manual (Page 497)

The effects |493
adapting reverb to the room size
Pa4X includes a master offset for all the reverbs. Use it to adjust reverb tails
to the room where you are playing. Use negative values when you are in a
very reverberant room, positive values if the room is too dry.
1 Go to the Global > General Controls > Basic page.
2 Use the Reverb Offset parameter to change the reverb master.