I was thinking that too for fair comparison. Maybe the right term is 'showcase' instead of comparison. I'll try to record same songs on SD40 and E-A7, I don't have the PA900 anymore.
Thanks my friend.
Ketron SD90, Ketron Midjay Pro, Korg Pa1000, vArranger, Bose L1 Compact, Roland KC-110, Aiwa Exos-9