ok suggest you read up internet reviews on good bargain 2nd hand Yamaha QY70 or QY100.

These are very versatile small portable battery [or mains] powered
midi sound-module / sequencer/ midi file players..

So heres a not so daft practical idea for gigging..
with the emphasis on being lightly equipped for running and jumping about manic stage performance...

..maybe a QY safely strapped into a slim shoulder or 'bum' bag
connected by a short midi lead to your Roland AX7..
Then just need to carefully run a long enough audio cable from the QY to your amp
or PA mixer.