Final success summary and potential failure points:
- MIDI Cable Confusion: Verify your cable connections. I accidentally successfully plugged a 5-pin MIDI cable incorrectly into a 7-pin port—easy mistake in tight spaces. Make sure you’re using the correct connectors.
- USB Power Issue: I was using a USB-to-MIDI converter with a standard USB extender, which failed to deliver power. The fix was using a direct USB-C connection into the CME HD4 behind the Fryette units.
- MIDI Routing Mistake: You cannot connect both ZMACS units using a MIDI Thru setup. Each unit must be connected directly to its own dedicated MIDI OUT port from your MIDI interface. Bypass any shared MIDI chain entirely—each ZMACS needs its own isolated signal path.
- CME HD4 Programming: You must use the CME software to assign:
- MIDI OUT 1 to only send program changes on Channel 1
- MIDI OUT 2 to only send program changes on Channel 2
- This isolates control for each unit and prevents overlap or crosstalk.
Thanks again for all the help. Hopefully this helps someone else, because most would’ve given up and grabbed a floorboard at this point. But even then, a floorboard wouldn’t let you independently control two ZMACS units with this level of precision. I’m glad I stuck it out.