(1) "to stream the setup I'm going to go directly from the Trinity to and from the XP-80"
I assume you mean "streamline" the setup; "streaming" something is a completely different ballgame in audio, and I have no clue regarding the MOTU timepiece.
But: For now, don't go "from" the XP80 back to the Trinity. Just go MIDI out from the Trinity to MIDI in to the XP80, otherwise, depending how the Trinity is set up with MIDI in/out/thru, you could get MIDI echo or MIDI slop or even worse.
(2) There's a small paragraph in the back of your XP80 manual about "Playing the XP-80 sound source from an external MIDI device"; you'll find it under "Using external MIDI devices". Make sure you've done everything in that paragraph, step by step, especially turning the part switches on.
(3) Start out by playing back just *one* channel of your sequence from the Trinity at a time to try to isolate the problem. E.g., play back *only* channel one and see if it plays on the XP80, then *only* channel 2, etc.
I can't stress enough how important it is to make sure, as the manual suggests, that the receive channel(s) in the XP80's performance *parts* (different from tracks) match the Trinity's *send* channels, and that the Rx (receive) switches are ON for the performance parts you want to address.
Try that and get back to us.
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Sorry for getting back late. The Synth Zone site has been all hosed for the past few days. Anyone know what happened?