Part number for Mutable Eurorack potentiometers

I want to build my own Braids using the open source PCB files. But I can’t find the part number for the potentiometers used on the production module (which I also have). Does anyone know? I sent an email to Mutable and I was told to sign up for the forum because there is no support for module DIY.

They are custom made by Polyshine in China. You would do well finding similar 9mm pots from Alps, Panasonic, Taiwan Alpha, Alpha, CTS, Bourns, and similar sources. However, you need to find out resistance, log/lin, shaft type and length.

Thanks very much for the response. Custom pots, hmm… has anyone else built a Braids or other MI Eurorack modules? What else will fit into the PCB without modification?

Alps pots fit. Others may as well. Panasonic pots don’t - the mounting lugs are too wide. You need to look at the footprint on the PCB, and the manufacturers spec sheets, very carefully.

Yes, Olivier has a very wise policy of not providing support for DIY builds of his Eurorack modules, because they were never designed or intended for DIY construction - they are designed for automated factory production.

It is possible to build them by hand, but it is quite challenging, and painstaking care is required. For example, 0603 sized components as used in the MI modules are generally not labelled at all - thus if you mix up the parts, then there is no way to tell them apart except by measuring them.

There is no instruction manual, nor any build notes. If you have specific questions, people on this forum who have built modules may be able to answer them if they have time, but don’t expect any hand-holding or answers to vague questions - if you aren’t sure what you are doing, then my advice is don’t attempt the build. Olivier has provided enough information to build these modules as DIY, but only if you enjoy solving puzzles - many of the essential details are not provided, and you to be prepared to research answers to them yourself. Don’t expect others to answer every question you might have, especially if it is evident that you haven’t made a reasonable or earnest effort to find or work out the answer yourself. That’s true of all unsupported DIY projects, of course.

Not all the DIY attempts at building MI modules have succeeded - some have been complete failures. If your build doesn’t work, then you’ll need to be able to troubleshoot it yourself, or be prepared to just throw it away and write it off to experience, unless you are set up with logic probes and other digital debugging tools. Magnification is essential for inspecting your soldering, especially on the parts with 0.5mm pitch pins. If you’ve never done SMD soldering before, then look at the various tutorials available on YouTube (I recommend the EEVblog tutorials), and practice on some simpler SMD DIY projects first. You’ll need the right tools - including a soldering iron with a needle tip, concave tip and very fine chisel tip, 0.4mm or smaller diameter solder (0.7mm is way too big), and no-clean flux pens and gel. Or a solder paste stencil and a reflow oven if you are doing it that way (but really paste and reflow is overkill for a DIY module).

Also, Braids is a digital module, and thus you need to be able to compile the firmware yourself and understand how to upload it. There are no precompiled binaries available. I suggest that you do that first, since it is a no-cost step - the entire toolchain is free and/or open-source. If you search this forum there is a thread describing how to build the firmware on a Mac - read that. Should work on linux too. I think someone mentioned somewhere that they built the code OK on Windows, so that may also be possible, but I don’t know for sure since don’t use Windows at all.

To be honest, if you need to ask the community about pots are you sure you can source and determine what other parts you need? I know it’s more than likely you’re just asking as a “shortcut”, just sayin’ :slight_smile:

@6581punk, yes, those were my thoughts too, hence my lecture about what to expect and what is involved.

Yep, I remember reading about one DIY build where some of the parts were salvaged off the PCB of some consumer electronics.

That was Schrab’s Braids, also made with Nixies IIRC-and it worked perfectly

Indeed, was the first DIY unit. But I don’t think salvaging chips from other PCBs was due to thrift, more due to desperation.

Scrab’s Siberian DIY build used a red LED display, but with a hand-etched PCB and voltage reference chips from a cannibalised mobile phone. You’re thinking of the 5U build with the lovely blue anodised and etched panel using Nixies, or were they VFDs, by nicoo.

Nicoo’s was through hole though, much easier to source parts and assemble. But requires you to design the PCB.


Life is so much easier when you know what you are capable of and what not.
If you can’t find out what Pots to use theres just one simple advice: don’t try to build it yourselves.