[Solved] MDX - "Momentary On" setting bugged


I’m trying to use buttons on the DuoX to trigger modulation events. I’m mapping the on/off switch of a module to a button of the MDX with the “Momentary On” setting in order to send a gate to an enveloppe and trigger a bunch of things.
It seemed to work fine, however I quickly found that the feature is bugged and the state of the switch starts to be locked in what looks like a “momentary OFF” state, meaning the button appears activated all the time but only deactivates when I’m pushing it.

How to reproduce

Button 2 of page 1 on this pedalboard (contains beta plugins) while playing some sound through the Mod Duo X:


The “momentary ON” should work as intended.

Additional Notes:
When creating a brand new pedalboard and trying to reproduce the bug with a only 2/3 modules loaded, I couldn’t reproduce the issue.

However the issue is consistent with my above pedalboard. This is already quite a “busy” pedalboard using already 45% to 55% CPU when idle. My guess is that the bug appears because of CPU load (it triggers an LFO with variable frequency which will itself alter parameters of cpu intensive modules --in this case a dual flanger–). Of course this is just a guess, I have no idea how I could verify this myself.

Additional information

Open the controller menu (hold left knob down), navigate to Info > Versions and write down here the versions.

  • release: v1.10.1
  • controller: 5F6073A

Also provide some information about your system if possible.

  • Operating system: Pop OS
  • System version: 20.10

Hi, Thanks for the report.

I actually just noticed now this does not happen exclusively on the DuoX, and already have a hunch of where the bug is coming from.

We will fix this soon!


HI, I am happy to report this seems fixed and will be released in either a 1.10.2 or 1.11.

in case you want to confirm, or are blocked in any way because of this bug, you can manually update your DuoX to this image that has the fix.

Please let us know if you have any other issues!


Great thanks!
I’m using a workaround at the moment with the latching setting so I’m not blocked. I’ll give a try to this image as soon as I manage to get some time to devote to music.

Is there a guide/procedure somewhere that explains how to make a manual update?

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yes, it’s all described on this wiki page!

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