i didnt have a chance to have a look at your code, etc. but your problem reminds me of one i have also with the midiface: truncated sysex-files orig: 3102 captured 2077 or less (i am trying to send sysex to the synth). only fireface behaves like that, all other midiinterfaces i used sofar have no prob. might have to do with timing. perhaps fireface has faster transfer. i can send the sysex with sysexlibrarian through ff400, which works. so probably the max-code has to be adapted to specific requirements of ff400.