I noticed you changed the DOC5503 mixer setup a bit and it helps a LOT! Very noticeable. All but one of the Chris Parana's Nintendo music files seems to play correctly now. wow.
I'll spend some more time on what's going on with his athletic.seq - it's almost like one or two instruments aren't being mixed a higher volume like they should or maybe the one is way too lound. Still doing comparisons between the a2fpga output and the Audio Animator output and Synthlab.
Will update as I find anything consistent that leads to something to fix....
Petar Puskarich