I have the FR1x which has only a single MIDI out connector (Not switchable like some other single connector Roland accordions ).
My bluetooth MIDi adapter „Quicco Sound mi.1“ is plugged in with one end, the other one is hanging loose.
It works perfectly - gets power from the FR1x and sends all data to my iPad for recording the notes.
I was even thinking of cutting of the second plug which I dont need. But I didn’t open the adapter yet to inspect the wiring if this could be done without damage.
BTW I did choose this particular device because it is much smaller than the Yamaha or the CME plugs. So I can leave it plugged into my FR1x and don‘t feel like it may get knocked off or will put too much stress / force on the MIDI connector of the accordion.
If you look at the „CME Widi Master plug“ you‘ll see that the plug which would go into the MIDI in of the accordion is detachable. Therefore I assume, you don‘t have to use it if you don‘t need it. The other part, the main plug, which connects to the MIDI out of the accordion is much bigger - probably because it has the full electronic. And I assume, this one only needs (and hopefully will get) the power from the accordion.
Regarding your Yamaha BT-01:
- Which part did you plug into your accordion?
- Did you try with your other MIDI gear if the BT-01 will work if only one part is inserted into the corresponding MIDI connector? (In that case of course only one way MIDI communication).
- If yes, does it have to be plugged into the MIDI out to work (get power)?