The Roland XP and JV synths can be expanded using Roland's SR-JV80 8 megabyte expansion boards.
The XP-50/60/80/JV-1080 can accept up to four SR-JV80 series wave expansion
boards at one time, to significantly boost the internal memory to a total of 40 megabytes.
The JV-2080 can accept up to eight SR-JV80 expansion boards.
These titles are currently available:
with many more to follow.
This extensive library can provide just about any waveform desired.