Custom Firmware on the OP-1

That tool helps but isn’t perfect. There are some SVG features that it doesn’t understand yet. I’ll be improving it in the near future, and hopefully I can get it to handle most if not all the quirks that the OP-1 SVG implementation has.

The usage (on linux) is simply:
./ original_filename fixed_filename

I just released version 0.2.1 of my op1repacker tool, and it now includes 11 iter presets from the community. To get them use the presets-iter option when modding.

I’ve also been playing more with the SVG stuff. I learnt a lot of new details about how the OP-1 reads the SVG files. I just updated the op1svg tool and the docs.

Now the tool should be a lot more stable, and does a much better job of cleaning up the SVG files. There might still be bugs though, so if anyone uses it and notices anything weird please report it.


If anyones interested I posted a (almost) complete history of the various firmware versions that have been released over the years:


nice! i have 216 i could send u if u want to add that to the list

Yeah why not, although not sure if that was some internal beta or something. I have 076 but have been unsure of whether to add it as it was the leaked beta. However it’s still available elsewhere on the net and all the stuff in the beta has been released anyway… Still, it’s interesting for research purposes.

here u go 216

i feel like since they’ve already surpassed the beta OS that its no biggie?


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Im sure I deserve a million scoffs for asking the following questions, but if anyone has the patience!?!

firstly I have never used python nor do I have much experience working with the terminal.

Can anyone walk me through the process of @wavi instructions.

Im literally starting from the bottom of this mountain of information and I was wondering if anyone could walk me through this with sole objective of using these custom firmwares. id be more then happy to learn more about the ins and outs, but to be completely honest I just want the firmwares. I apologize if what im asking is hard too understand. this is the equivalent of a Neanderthal asking an advanced extraterrestrial being for directions. Id be more then happy to compensate your for your time.

Thanks, will add that to the archive in the next update :slight_smile:

It shouldn’t be too difficult to install and run the op1repacker, but lets start with the basics: What operating system are you using on your computer?

OS 10.14.4! and thank your for your time Wavi!

Thanks! I don’t have Mac OS but I’ll try to write a step by step guide here. I’ll probably improve it and eventually put it in the official documentation for the tool. In any case the essential steps are the same for every OS.

Mac OS step by step instructions for using op1repacker:

Step 1: Get the firmware file that you want to modify

First you need to have a firmware update file, here’s how to get one.

Step 2: Get into the terminal

In this step we’ll need to make sure python3 is installed since Python 3 is the programming language that op1repacker is written in. It might already be installed on your system but well check and install it if it’s not.

First we’ll need to open the terminal:

  • Mac OS: Open the Terminal App on your system (more info about Terminal here:

  • Next lets see if python3 is installed.
    In the terminal type the following command and press enter:
    python3 --version
    If the output looks something like Python 3.X.X then you have python3 and can continue to step #3. For example:
    Python 3.6.7

If you get an error from the command above (something like command not found: python3 you’ll need to install Python 3 yourself. I would recommend checking out one of the following guides:

Drop a message on the forum or an issue in the op1repacker GitHub repository if you need more info about installing python3 on Mac OS.

Step 3: Install the op1repacker tool

  • In the terminal run the following command:
    pip3 install op1repacker
    • Alternatively try pip install op1repacker if that doesn’t work. You might also have to add sudo to the beginning of the command if it says something like permission denied.
  • You should now have the latest version of the tool.
  • To make sure the tool works run the following command:
    op1repacker -v
    If the installation worked you’ll get a version number. For example:

Step 4: Create your custom firmware

  • In the terminal, go to the directory where your firmware file is. If the firmware file is in your home directory run the following command:
    cd ~
  • If the firmware is in some other directory you can navigate to it in the terminal this:
    cd /path/to/folder

Now is the fun part, modding the firmware. The commands below use the latest firmware op1_235 as an example. Change the filename If you are using a different firmware version.

  • First unpack the firmware file by running:
    op1repacker unpack op1_235.op1

  • Now you can mod the unpacked firmware. The available mods are described here: For example to enable all the available modifications run:

    op1repacker modify op1_235 --options iter presets-iter filter subtle-fx gfx-iter-lab gfx-tape-invert gfx-cwo-moose

    You of course can leave any of the mods out if you don’t want all of them.

  • Now that the mods are done you can get your installable custom firmware file.
    Repackage the unpacked firmware with this command:
    op1repacker repack op1_235

Now your folder should have the file op1_235-repacked.op1. Use this file and run the normal OP-1 firmware update with it to get the mods. Enjoy!

Hope that helps, let me know how it goes and if you need more help!


this is amazing!! I’m learning so much more about navigating my machine thank you!! but unfortunately I’ve run into an issue, maybe you can find an error in my command input?
Codys-MacBook-Pro:~ codygadsby$ pip3 install op1repacker

Requirement already satisfied: op1repacker in /Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages (0.2.2)

Requirement already satisfied: svg.path in /Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages (from op1repacker) (3.0)

Requirement already satisfied: setuptools in /Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages (from svg.path->op1repacker) (40.8.0)

You are using pip version 19.0.3, however version 19.1 is available.

You should consider upgrading via the ‘pip install --upgrade pip’ command.

Codys-MacBook-Pro:~ codygadsby$ op1repacker -v


Codys-MacBook-Pro:~ codygadsby$ cd ~

Codys-MacBook-Pro:~ codygadsby$ cd /path/to/folder

-bash: cd: /path/to/folder: No such file or directory

Codys-MacBook-Pro:~ codygadsby$ cd ~

Codys-MacBook-Pro:~ codygadsby$ cd

Codys-MacBook-Pro:~ codygadsby$ cd…

-bash: cd…: command not found

Codys-MacBook-Pro:~ codygadsby$ cd …

Codys-MacBook-Pro:Users codygadsby$ cd op1_235.op1

-bash: cd: op1_235.op1: No such file or directory

Codys-MacBook-Pro:Users codygadsby$ cd …

Codys-MacBook-Pro:/ codygadsby$ cd/

-bash: cd/: No such file or directory

Codys-MacBook-Pro:/ codygadsby$ cd /

Codys-MacBook-Pro:/ codygadsby$ op1repacker unpack op1_235.op1

The specified path “op1_235.op1” doesn’t exist!

Codys-MacBook-Pro:/ codygadsby$ cd …

Codys-MacBook-Pro:/ codygadsby$ cd …

looks like maybe u need to ‘cd’ or change directory to the actual folder your .op1 firmware file is

so like if your file is in documents
your command might look like ‘cd /users/admin/documents’

use Finder to figure out the correct path to where you saved your .op1 file

or conversely u could move the .op1 file to the home directory and then cd ~

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Ok thank you so much I will keep fidgeting with it

I figured it out!!! Literally thank you guys so much !!!

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Awesome! Can I ask which mods you used, if any? And what are your thoughts on them?

I used the ones in the instructions tbh! the Iter mod is a lot of fun, there is going to have to be a lot of experimenting in my part. I did notice the patches do not show up in the initial menu list, but they do show up when holding shift and then selecting the instrument. The filter effect is something I have been desperately trying to get my hands on for transition purposes. I would like to find a way to animate the ITER synth a bit more just for superficial value. also the tape inversion is clearly superior.

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This tool is essential to me! I’ve been using it for a while, but recently repacked firmware with:

  • tape on top
  • filter
  • subtle FX

I could do without most of these, but the tape on top makes things so much easier to see. Thanks for such a great tool!

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A link to a song I made with the new stuff

A link to the rough cut mix

So this isn’t working for me. Iter only shows up on Shift+T1. There are no presets. Pressing Shift + preset slot shows the old list of synths with Iter missing - which then wipes it from the slot.
FWIW all the other Mods seem to be working fine. I followed the procedure posted by @wavi several posts up.