Subsequent 37 tuning problem

[esmeets]

Hi,

On 26 June this year I purchased the Subsequent 37 from Thomann. I updated the firmware to version 1.2.0 via Sysex Librarian, manual update since Firmware Updater could not be opened on my Mac Mini with OSX 10.14.6. For this update I used a 1.8m USB cable which was directly connected to my Mac. The firmware update went well.

I also loaded a number of presets from the Audiotent website into the memory of the Subsequent 37 via the VST editor (B01-P01 till B07-P11)

The 3rd or 4th time I turned on the S37, I noticed it was suddenly out of tune so I started the "Note Calibration" option via the VST editor Cubase Pro 10.5, again using a short USB cable for MIDI. After this calibration, everything was fine again

After a few days I turned on the S37 again and it was out of tune again...
I made a video of this, the first octave is from the Slim Phatty and the 2nd and 3rd octave I play is from the S37, both connected via USB and played with my NI Komplete keyboard (it doesn't matter if I play with an external keyboard or with the keyboard of the S37 itself).
https://www.dropbox.com/s/varj2ih48nc9q ... 8.mov?dl=0

The sub37 is now connected via a Belkin Powered USB hub to my Mac for MIDI. there is no difference if I connect the S37 directly with USB to my Mac (which I did for the firmware update and calibration, by the way). The synth is now back in tune (after calibration) but I have no idea how long this will last unfortunately.

These are the current settings on the S37:
Tuning Scale 12T Equal temp
Scale number 0
Variance 0,0C
Note calibration start note 15 end note 116

Does anyone here got any idea what might be going on here?
Thanks

Kind regards,
Erik Smeets

[Astheologos]

You don't need to connect anywhere for calibration!
Just disconnect all cables except the power supply.

And carry out the calibration via the Global Menu 3.1
I also had one key out of tune, now it works fine!