Hi (yammie)guys,
one more thing, you MAY be able to edit pads in a pc sequencer using the renaming function ie
bell.pad change to bell.mid
All 4 pads show up in the sequencer , 1 per midi track.
Basically change extension from .pad to.mid
Load in, do a quick edit, press "save".
Then "Undo" the rename which changes it back to .pad.

Haven't tried it recently, but I did do it for my psr 1500, years ago. Maybe internal pad editing has improved since then, so may not be of benefit. ?