[cberg]

Hi, many of us have experienced the Divisions knob loosing functionality when updating the OS on older Koma Komplex Sequencers.

I got these instructions from Christian at Koma with the permission to share them on this forum.


Boot into the Testsoftware
• To boot into the Testsoftware hold the following buttons while powering the machine:
• STEP - GLIDE - SSP - GATE
• This will bring you to the "Color Setting Menu" (check the manual if you're interested in changing your colors)
But there is a hidden division calibration too! To enter the correct menu for calibrating your divisions press and hold MODE, then press the first step button (step 1) on all four sequencers. This will bring up the "light show" that we use for testing LEDs. Now press and hold MODE and press step 6 on all four sequencers. Now you're in the Division calibration mode for each sequencer. To set them do the following:

1. Turn the `Divisions` knob to counter-clockwise, until it can't move anymore (to the :32 division).
2. Press the left most `Step` button (Step 1). The LED of the slider above should light up / move to that position.
3. Turn the `Divisions` knob one position further clock-wise. Press the `Step` button to right of the last one that you clicked (now Step 2). The LED of the slider above should light up. (This saves the position of the knob.)
4. Repeat steps 3 until all the knob doesn't move anymore. (You are doing it right, if the LEDs light up from left to right.)
5. Press the `One-Shot Mode` button of the sequencer you just calibrated to save the configuration to the EEPROM, so it is saved after the unit has been turned off. Now all the LEDs in the row should light up. Wait until only one LED lights up again.
6. Move the `Divisions` knob. The LEDs should now move with the position of that knob. Check if every position of the knob has one LED light up. If not, repeat steps 1 to 5.

You need to repeat this for every sequencer (sorry). And then your divisions should work again. Sorry for the hassle. But really it doesn't take very long and will make your Divisions more stable than ever before.


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that's it - hopefully this thread can help you if you get stuck like me :)
best christoffer

[ilyacolton]

Hey man, I'm wondering why the Divisions knob specifically loses functionality every time the OS is updated on older Koma Komplex sequencers, but other knobs don't? Does Koma plan to release a firmware fix so we don't have to manually calibrate it every time there's an update?

[shaneronan]

Oh man, that issue with the Divisions knob losing functionality after an OS update on older Koma Komplex Sequencers is a real headache for a lot of people! So glad Christian from Koma shared these fix instructions, and even gave permission to share them publicly – that's awesome!

[chrisi]

Christian here, quick clarification: The Divisions knob is a special case because it is a potentiometer with 11 detents. Notice, how all other knobs on the Komplex turn continuously but the Divisions knob lateches into 11 distinct positions. The issue is that these detents have huge tolerances and the spread between them is very irregular. This becomes worse on either end of the knob where resistance often changes less than in the middle of the potentiometer.

For the sake of simplicity, let's imagine, we have a 100K resistance potentiometer with 9 detents -> that would be 10 zones or 10 divisions available. You would probably imagine that the 10 zones (detents) sit evenly spaced at 0K, 10K, 20K, 30K, ... 100K.


The reality is that the detents will look something like: 0K, 1K, 1.2K, 2K, 10K, 20K, ... 90K, 92K, 98K (exaggerated). Now this is something that we can take into account in the firmware to some extent but imagine every 10th or so potentiometer coming with: 0K, 1K, 1.6K, 2K, ... now the firmware has a really tough time deciding if 1.6K still belongs to 1.2K or to 2K and divisions might jump around. There are more engineering challenges to this but this is the core issue.

On older models we have solved that manually by "nudging" the pots a bit up or a bit down by hand-soldering resistors to them, so the zones spread out a little more evenly, especially on the lower zones where the :32, :16, :8 divisons sit. But that sometimes may lead to errors in the higher divisions (4x, 8x). Additionally, when pots age - and some Komplex Sequencers are older than 10 years by now - these resistances shift around even further.

So with the latest firmware update, we coded an on-machine calibration mode. This is what you are doing when you calibrate your Divisions knob. You essentially learn your Komplex your exact potentiometer zones on the Divisions knob. We do this here before ship out any new sequencers but for any sequencer already out there, you need to do the procedure once and then never again. The specific zone settings to your Komplex will persist over all future firmware updates.

We thought it's a small annoyance that helps have extremely stable divisions. Unstable divisions come up every once in a while in support. Now we know for sure that any Komplex Sequencer that has uniquely calibrated Division knobs will never suffer from such an issue. Not now and not in the future.

I hope that helps! If you want to know more, just let me know :)