I would like to conduct a quick survey to understand how many devices currently on the market have a MIDI OUT port with pin 4 (the central pin!) connected to ground, without which the RK-002 cannot be powered.
So far, I’ve tested two instruments:
The Numa Compact 2 (and I imagine the 2X, since they’re sisters) is not compatible, but a simple modification can be made to make it work perfectly.
The Ketron EVM works perfectly; both the OUT and THRU ports are grounded and power the RK-002 (most likely the rest of the Event family too, such as EventX, Event-76, and Event-61).
Arturia BeatStep is absolutely not compatible: the MIDI port only has two connections, and even when grounding it, no power is supplied.
I would love to know if anyone has tested other master keyboards, such as the NOVATION Launchkey 88 Mk3 or the Arturia KeyLab Essential 88 Mk3 (although I have received negative reports about the latter, which isn't surprising since the BeatStep doesn’t work either).
What devices are you using where the RK-002 works without issues?