Left knob bad in 1.10 (DUO)


in v1.10, the problem of the jumpy/unresponsive left knob on a DUO might be worse.

How to reproduce

  1. update DUO to 1.10
  2. assign left knob to any parameter (or even just try to navigate the system menu)
  3. response is poor and jumpy, and it sometimes jumps back to the minimum value when operating in the bottom half of its range.

Expected/suggested solution

the left knob should work smoothly, as the right one does! :wink:

Additional information


  • release: 1.10.0
  • controller: F017FFS


  • Operating system: macOS
  • System version: Big Sur 11.3.1

as you know, this has been a long-standing problem. i’m reporting this, because i think this got worse in v1.9, and even worse now in 1,10 – although it’s hard to quantify, of course. i did get a main circuit board replacement in May, 2017. at the time, that seemed to solve the problem, so i’m a little worried if this has gotten worse again in recent software revisions.

unfortunately, i am unable to install versions earlier than 1.9 to re-test this, since i had to do the NAND conversion on my particular DUO.

I must say that I didn’t read more reports of this issue, can’t it be something faulty in your Duo?
Anyway, I will ping the developers to learn more

in case it helps to track things down… my correspondence about the issue in 2017 was with ricardo crudo (i gather he’s no longer at MOD?).

It actually helps to understand the source of your issue.
We must say that we are not so familiar with that issue, which means that it doesn’t pop up so often and probably it is something faulty on your device.
Could you please send an e-mail to support@moddevices.com? It would help a lot if you add a video showing the behavior.

here’s a thread in which ricardo and i discussed it a bit, through some firmware revisions:


…yes, i’ll make a video. that will take me a few days.
stay tuned…

Thanks for sharing. We will investigate in the meanwhile to understand what can be happening.

sorry for the delay… it’s gotten busy in my studio! :stuck_out_tongue:

here’s a video: plutek DUO - left knob fault

first, i slowly turn the left knob. even though i am always turning clockwise, you can see that the values frequently jump backwards and the upwards progress is halting and unreliable.

then, i move to the right knob and do the same kind of turning. this one moves reliably upwards, arriving at maximum predictably.

Thanks for sharing the video. It the quite an annoying issue, but not common at all! We will be taking a closer look at it. I will get back to you with news soon.
Meanwhile, if you can help us, could you please send the issue and the video to support@moddevices.com? Just to help us keeping track and getting it solved. You can even add a link to this post.

ok… i just sent an email to support!

thanks, @jon!

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