Fehler Fabrik Modules - beta, code review

Is it okay if I just upload the build to you?

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Thanks, I’ve updated the release to include this.

I’ll be able to sort Linux builds myself as soon as I can fish out an appropriate USB drive to boot Ubuntu from, I refuse to buy another one when I know I’ve got some hiding somewhere…

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lol, well I’m happy to help until you find those sneaky usb drives.

I appreciate the work you do. Thank you.

Hi Ross, just one little question, could the sigma module be changed in the layout?

imho it is not really logic,

that the lower values are on the upper half and the higher values are on the lower half. (see the VCV octave module)

but maybe you have some reason for this layout.


Agreed, I’ve updated Sigma to have this layout.

Honestly I don’t think there was any reason for it in the first place, I made that module pretty quickly without putting a lot of thought into the layout.

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I’ve created a new branch that adds polyphony to Fax, as requested on GitHub. It’s pretty untested, and it makes an already esoteric module even more complicated, so please let me know if there’s any improvements that could be made.

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I’ve now also added polyphony to Sigma and Planck. In adding polyphony to Sigma, I found that clamping all possible output channels (16 * 8 = 128 channels!) was seriously increasing the sample generation time, so I’ve removed it for now. IMO this is a reasonable trade off - if a user inputs 10V they’re only going to be getting 14V out of it, so it shouldn’t create a voltage that’ll be wildly out of the realms of possibility. For what it’s worth, the Fundamental Octave module also doesn’t clamp it’s outputs.

I have one more module that I’d like to implement, then I’m going to focus on tidying up the panels and making sure everything conforms to the voltage standards so I can release these things on the VCV Library.


That’s the last module now added to the polyphony branch, a three band isolator with 4th order 24dB/Octave Linkwitz-Riley filters, inspired by classic rotary DJ mixers and PA crossovers. Use it to split a signal up for multi-band processing, or for more precise tonal balancing than a normal DJ EQ can give.

While it does work with polyphonic channels, it’s not well optimised for this yet - give me a little bit of time to learn about SIMD and we’ll see if we can squeeze some more out of it.

As always, please let me know if there’s any improvements to be made. This is my first time implementing a DSP filter (I don’t think the DC blocker in PSI-OP really counts), so the function for that is a mess. Hopefully I can neaten it up when I’m looking into the SIMD stuff.


Wow, some of these look really great so far. I hate to be a bother, but I can’t seem to get installing these modules to work for me, is there something that I need to do past the typical installation for packs not on the library? Is there somewhere else I should be downloading the zip from other than your github?
Thank you, and if this question has already been answered somewhere else, sorry.

What operating system are you trying to install on? I’ve just added the latest distribution ZIPs for all OSs here. You should just be able to add the ZIP files to your user folder as described on this page.

All the important stuff should be in those ZIPs. If you’re not having any luck after copying the relevant one to your user folder, please let me know what the content of log.txt in your user folder is after trying to install.


Thank you very much, I have it working now.

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This is a really minor point, but in your tags for the Psi Op in plugin.json you have “Drums”, “Drum”, and “Percussion”. Because “Drums” and “Percussion” are deprecated, they each get turned into a separate “Drum” tag in the module browser.


Any plans to push the plugin to the library?

Psi OP has never left my rack, and I think more people should get to play with it. I’m not sure how “done” the rest of the collection is, but unfinished modules can just be disabled in the manifest

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@hamptonio - Thanks, this has been fixed

@Aria_Salvatrice - I’m thrilled to hear you’re still using Psi Op. Further development has obviously slowed to glacial, a downside of going back to work post-lockdown. I think I’m happy enough with all the modules as they are now though, and they should be ready to be released onto the library. Hopefully I’ll get them up tonight, if not then by tomorrow for sure.


I’m not simply still using it, I like it enough I’m working on a companion module for it!

(Well - one that can be used for many other modules than Psi Op too, but it’s the one that inspired it, and that I obliquely refer to in the name. Details in my dev thread if you care :D)

Glad it’s gonna be available to a wider audience soon.


The modules are now on the VCV library. I’m not sure how progress is going to go from here tbh I’ve got a few ideas but I think it’ll be a while before I have the time to develop them properly.


absolutely love their design language, looks playable and fun!


I can’t recommend enough the source code for the Fundamental modules, and in turn the simd library that’s part of the VCV SDK. I guarantee you will get it really quickly. Almost all the Fundamentals use SIMD to speed up polyphonic stuff (and other things) in a way that is really easy to understand. Or maybe it’s because the SIMD stuff (esp the float_4 struct) is so good.


Unrelated to the code, I apologize, but these modules are super amazing.

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