KORG PA4X 76 - Manual (Page 469)

Making new sounds with Sampling |465
Deleting all the unassigned samples
▪ Select the Not assigned to any Multisample/Drumkit option, and touch OK
to confirm.
This command deletes only samples not yet assigned to any Multisample or
Drum Kit. Use this option with care, since you may delete samples you would
like to preserve, but have not yet been assigned.
Deleting all the samples, multisamples and drum samples
▪ Select the All Samples, Multisamples, Drum Samples option, and touch OK
to confirm.
Select this command to delete all samples, multisamples and drum samples
from the RAM memory. This operation completely resets the RAM, and may
be used to clean-up any trouble with memory management.