MIDI Merge Unit + Arduino Micro

Hey all,

Hoping someone might be able to help me out.

I have a built a MIDI controller using the Micro circuit. It works as expected when plugged directly into the units its controlling.

However, when I plug it in to a Kenton Merge 4 unit to control two units simultaneously, it fails to transmit anything. I've verified the Merge 4 unit works with other MIDI devices though.

If anyone else has every run into this issue, please do speak up!