Convert Note On velocity = 0 → true Note Off max device

Hi everyone 👋
I don’t really have a background in programming, but I really appreciate this community and all the amazing work people do here 🙌🍺

I’m having some issues with my MIDI setup involving a few older MIDI synths.

I’m currently working mainly with Ableton Live 11. I’m a long-time Cubase user, and lately I’ve also been enjoying Bitwig quite a lot.

When I send a simple melody from Ableton to my MIDI-fied Polivoks and also to my Elka Synthex, I get stuck notes when I press Stop.
For a long time I thought this was a hardware issue with the synths themselves. However, a few days ago I tested the exact same MIDI material in Cubase and Bitwig, and the synths stop cleanly there no stuck notes at all.

After digging into it a bit more, I realized that Ableton does not use “true” MIDI Note Off messages, but instead uses the newer implementation of Note On with velocity = 0 to indicate Note Off.
It seems that some older synths don’t fully handle this behavior, which may explain the stuck notes.

We came up with the idea of creating a Max for Live MIDI device that would convert “Note On with velocity 0” into a true Note Off message.

ChatGPT helped generate some code for this, but I don’t really have any programming knowledge, and I wasn’t able to implement it successfully.

So I was hoping someone here could help either by explaining how to do this properly, or maybe even by coding a simple Max device that does exactly this.

Any help would be very much appreciated, and I’d also love to understand more about what’s going on under the hood.

Thanks a lot!

bst rgds

isaac sandman

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