The following is copied from the email I received from Arturia. I'm pretty sure the Debug calibrations are what fixed mine.
Could you please confirm for me if on each power-up of the unit any message such as "PolyBrute Cold" message is being displayed on the screen?
Important note:
If so, make sure to always confirm the calibration immediately on power up for the unit to store further calibration values related to your ambient temperatures. Normally, after having stored enough calibration values on each power sequence you shouldn't see these messages being displayed anymore (as long as there are no significant ambient temperature changes).
Could you please first confirm me that you ensured updating the PolyBrute firmware or if already updated to the current version to reinstall it properly ?
First, even if your presets shouldn't be altered, make sure to first backup your presets as safety measures through the "PolyBrute Connect" utility.
Once done, you can then proceed:
- Press the "Settings" button
- Then press buttons "8" Misc and finally "3" Factory reset
From there the unit parameters should be reverted to their default values.
Now make sure to let your PolyBrute warm up properly for at least 20 minutes (even 30 minutes if you'd like to be definitely sure that the oscillators are perfectly stabilized) then proceed with another calibration to confirm if this still persists afterward or not.
If this persists, make sure to also try the suggestion below:
- Press "Settings"
- Press button "8" (Misc)
- Press button "4" (Voice Auto-Tuning)
- Press button "4" (Restore)
You may have to proceed with another calibration of the VCO and of the VCF afterward before giving it another try.
If the suggestions above didn't help, trying also to reset of all the calibration values stored in the unit may be also useful:
To do so, please use the "Debug mode":
- Press at the same time Motion "Rec Arm" + "Morphee" Mode buttons:
The message "Debug Mode ON" should be then displayed on the screen.
- Then to enter the "Reset Voice calibration" menu, you'll have to Press and Hold at the same time the "VCO1" then "VCO2" & then "Noise" buttons located in the Mixer section (In the precise order mentioned).
- You'll then have four options:
(1) VCO calib Reset
(2) VCF calib Reset
(3) VCA calib Reset
(4) All Reset
- Press the button (1) below the display to proceed with the VCO values deletion.
- From there, still once having ensured that the unit properly warmed up, make sure to proceed with another VCO calibration.
In case, calibration failures after having proceeded with these steps keeps on occurring, i would suggest you to ensure also trying to first:
- Power OFF the unit and unplug it from its power source
- Then let it rest for a few hours
- Power it back again and then proceed with further calibrations to confirm if this still occurs or not
Finally, if you're still unable to resolve the issue, make sure confirm which precise voice seems to be faulty:
Still once in "Debug mode":
- Enter the "Voice debug" mode proceed with a long press on the "Polyphony" button