Hi Tom! Have you looked at Claude's excellent tool "MIDI Commands Spreadsheet" at http://www.loopersdelight.com/tools/echoplex/echoplex.html ? Loop IV uses considerably more MIDI commands than Loop III. When I set source # to 31, for example, the Spreadsheet shows MIDI Note or Controller numbers 75 and 76 as the EDP functions BeatTriggerSample and MIDIBeatSync. So I think your EDP is responding to these controller numbers. Hope this helps... Dennis Leas ----------- dennis@mail.worldserver.com