Freeze pedal on the horizon?

I’d love a Freeze pedal :slight_smile:

  • like the ElectroHarmonix - EH nano Sound Retainer
  • on the Mod Duo

it holds/freezes whatever sound is passing through the pedal at the instant the switch is activated,
with some practise you can use it sort of like a piano sustain pedal

Any idea if that’s a possibility?


Hi @broupe,

I had a plan to do such a plugin and designed a prototype in python that works pretty well, but never had the time to dig into lv2 plugin development to make it go to the next step.
I involved a friend which is much better at C++ than I am but still not a LV2 expert and the project is going slowly.

So if a LV2 expert is interested in collaborating on this project, we could make it !
my prototype is already written in a “realtime” fashion and uses FFT/iFFT.


Hi Romi

thanks for your prompt reply, sounds fascinating; I wish I could be of any use,
I play with these sounds on an everyday basis, so I know what works and what doesn’t,
but I can’t do any programming at all, sad to say…
I hope someone that has the ability will hear our plea and rush to our help! :slight_smile:
How do we find someone who knows LV2?


I consider trying something like that as well, but I couldn’t wrap my brain around it, yet. :wink:



We already have a ‘Stuck’ LV2 for this in the Linux world developed by @ssj71 here:

I don’t know how or when his great work will make it inside the MOD, he has several cool plugins on his page there that would be awesome additions,

Any comment @ssj71?


i’m in the process of porting some plugins over from my JS fx in Reaper.

the first two (usable by devs but not finished yet) are described here:

…but the next one i’m going to do once those have UIs and stable param ranges is called ‘avocado’, which is a stutter/glitch pedal. i could give it a freeze mode pretty easily, i think. but it would probably be a very different flavor to the other plugs described above.

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Its on the closer side of the todo list. I was going to actually do a sequel for it because its not as clean a freeze as I’d like, but its useable so maybe I should port them first and make the new version after.


Hey romi:
is the code open source? I’ll pitch in if you have it posted somewhere.

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Hi @ssj71
The python code is on github:
My friend should push a C++ transcription of the code on the repo soon (if he can find time to do so !).
If you can help, that would be great for us.

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that would be great. Once thats done the rest shouldn’t take long. You might mention to your friend that the ffmpeg fft library is currently the fastest to use for MOD. :slight_smile:

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Don’t suppose there’s any news on this? IIRC @romi’s code is entirely separate from the Infamous Stuck and Freeze pedals already in the store, right?

IIRC Freeze IS romi’s code.

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Hi all !
I missed the last messages !
We released about 3 months ago a beta version of the Mr Freeze plugin which is an implementation of a freeze pedal (which I think is quite similar to the Infamous stuck).
It is still with the unstable plugins so you have to activate unstable plugins to see it (see here to see unstable plugins).

I’d like to have some feedback about it, so if you tested it and you have any comments on it, feel free to tell me !

For those interested in the code, you can find it on github (We also take the comments about the code.)


So, how do I get this on the Mod Duo? Is it not a full-fledged pedal? How do I install this - can anyone help?

It’s explained in the previous post.

I can’t seem to locate this plugin even after enabling ‘Show beta plugins’. Was it removed from the store?

I’m stupid, it’s there.
Doesn’t work that well though, there are periodic artifacts when the freeze is activated.

Have you tried the infamous stuck? It certainly isn’t perfect, but I’ve really tried to tune it as much as possible to be smooth. I think to get any better you can’t operate in the time domain.

Yeah, I’ve tried Stuck, it works pretty well, but not as well as a real freeze pedal.

I believe MrFreeze tries to do the right thing using FFT but there must be a bug there somewhere.

It’s actually been on my todo list for a long time to find / make a replacement. I’m trying to build the mod-plugin-builder right now, that will at least bring me a little bit closer to some experimentation.

Edit: replacement for the real pedal that is. Was a bit unclear.

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Looking at the paulstretch algorithm has been on my todo for a long time. You might check that. Another approach that actually is time domain is something like wsola or randomized grains. That could work very well. This is slightly different from my approach of just creating a single looped sample.