SetBFree endless loop on rotary CC configuration


I have a midi keyboard driving Zynthian on a Pi 5. I am using SetBFree and controlling the rotary / Lesley effect from the mod wheel CC1

I find that occasionally the rotary effect will start doing continuous random things without my input. Disconnecting the midi keyboard does not change this random behaviour.

If I look at the Midi Log I see continuous random CC1s and CC67s messages. This behaviour also starts to cause XRun warnings on the Zynthian display

The problem appears to be SetBFree itself. If I go to Patchage and disconnect SetBFree midi out, the problem goes away. So I assume that for unknown reasons SetBFree is receiving these CC messages, then passing them on to its output. Because of the way its wired in the ZynMidiRouter it then gets those CCs returned and goes into a loop. Dont know why it doesnt do this continuously

So deleting this connection is a workaround, but if I reboot Zynthian it returns with that connection restored and therefore susceptible to looping the CCs

How do I make this workaround permanent ?


Hi @MalcolmGillott !

Please, open an issue in our issue tracker at GitHub and we will solve this issue ASAP.


I had the same problem. Reboot sometimes helped, if not, I had to power off and start again. I noticed that the error occured when I sent “too much” midi messages to setBfree: moving drawbars (sliders on a midi controller) or the modwheel and playing notes together. My workaround now is not moving drawbars when playing, and use a toggle button on the midi controller for CC1

@jofemodo . Thanks. Issue raised

I had the same behavior a couple of weeks ago. I was using the pitch bend and modulation controller when it happened

It’s fixed! Please, update and test.


@jofemodo I’m assuming its the testing branch ? If so, looks like you nailed it!
Well done and thanks!