Mutable Instruments Marbles - Secret Modes and Calibration - DIY Clone

I built another Mutable Instruments DIY clone, this time Marbles, and stumbled over some modes, when using external sampling sources, which I did not find in any manual or description.
So I wanted to share those modes here.
Besides, the module calibration is more complicated, than for other Mutable Instruments modules.
So I also describe it in more detail here.
Information about how to build the module yourself are available again on GitHub:
github.com/TOILmodular/MARBLES/
I also created another GitHub repository, describing the method of compiling the source code in a relatively easy way, since that is required for the calibration process.
Here the link to that repository:
github.com/TOILmodular/MI_FIR...
I would be happy to get some comments, in case you successfully managed to build the module yourself.
Of course, you can also comment, if you have any question.
Enjoy.
0:00 - Intro
1:38 - External Sampling - Demo Setup
2:26 - Green Mode: Shift Register
4:34 - Red Mode: Chords
6:54 - Orange Mode: Strange Hybrid
8:39 - Calibration
9:02 - Step 1: Measuring X1-X3 CV Outputs
10:50 - Step 2: Measuring Y CV Output
12:01 - Step 3: Calculating Offset and Scale
13:10 - Step 4: Adjusting the Source Code
13:35 - Step 5: Compiling the Source Code

[@NikolaosTsarmpopoulos]

Thanks for sharing the video. I built the module and compiled the firmware. I'm now looking into calibrating it. My UNI-T UT50A multimeter is only 2000 counts and I wonder if it's good enough in practice. What's the difference -in practice- between an un-calibrated Marbles module and a calibrated one?

[@TOILmodular]

The calibration is needed for the internal quantizer. So without that you might not get accurate CV outputs, when using the scales of the module. I do not know how accurate you can get with the 2000 counts. But it is definitely worth a try. If it sounds good enough, it is good enough, I would say.

[@Rinzler4DP]

Those oscillators sound really good! what are you using?

[@TOILmodular]

The high pitch voice is done with my rebuild of the Kassutronics VCO. I showed it in the 1st video of my "Finding modules" playlist. The sound is done with 2 of those VCOs via FM. I shared that technique also in my "Bells" video. The 2 lower voices are from 2 Plaits clones. Unfortunately, I did not take notes about which models I used for the sound. I just played around with them, after I built them.

[@observanus]

Great walkthrough! I need to calibrate my factory Marbles (quantized CV is flat) and tried to calibrate and compile into a Wav file since I don't have a programmer but it does not work. Do you know if it's possible to offset the DAC via a .wav firmware or do I need a programmer? Thanks a bunch!

[@TOILmodular]

I have not tried that myself. But I am pretty sure that you can do that, if you can create a WAV file from the code adjusted with the calibration values. At least the MI documentation describes the procedure of uploading the firmware via an audio file.

[@observanus]

@@TOILmodular Cool, I’ll give it a few more goes. Thanks a bunch, appreciate it!

[@maerisrael]

Hi I was wondering if you have Gerber files for front panels for your designs? I'd like to build a few of them but I'm unclear how to get the panels fabricated. Thanks for publishing through hole designs for the MI modules...

[@TOILmodular]

Thanks for your feedback. Honestly saying, I was thinking about that at the beginning. I did not want to do it, since I do not follow the HP standard for the width. I use sliding nuts. On the other hand, I already got that request a few times. So I started thinking about providing panel Gerbers. Cannot promise yet though. I will let you know.

[@maerisrael]

​@TOILmodular maybe using oblong pill-shaped mounting holes would accommodate nonstandard hp width for either sliding nuts or fixed width inserts. Check out the Antumbra 6Mix front panel, for instance. Would love to build several of your designs (plaits, clouds, and tides) if I can also get the panels fabricated!

[@TOILmodular]

Thanks for the advice. I have to admit, I am not a fan of those holes, as they are a pain in the… when using sliding nuts. But it is not just the mounting holes. I also have to adjust the module width to avoid gaps between modules. I also have to think about pot hole diameters, etc. I am currently thinking about it. Not yet decided.

[@btAC242]

Hello! can you explain what is local ARM folder in your "Compiling Procedure for Mutable Instruments Eurorack Module Firmware", what is ARM/stmlib? there is no stmlib folder in ARM from this repository...

[@TOILmodular]

Thanks for the feedback. You are right, that step 3 was not described correctly. You actually find that folder Stalin in the downloaded code from MI (step 1), not the one from my repository. My mistake, I adjusted the text in step 3. Let me know, if it is still unclear.

[@btAC242]

Thanks. guess i do everything right and have this: stmlib/makefile.inc:373: build/marbles_bootloader/depends.mk: No such file or directory @@TOILmodular

[@TOILmodular]

I fear, I do not quite understand. What process step are you at, and what problem do you face? You can send me an email to share more details.