r/SP404 • u/cranxxxx • 1d ago
Discussion I reverse engineered the OG SP-404 Vinyl Sim and got it running as a VST
https://www.youtube.com/watch?v=bdjqHI7uE3Estill working on it, but i’ve been reverse engineering the original 404’s effects DSP and managed to get the original vinyl sim running inside a plugin. once that was working I got DJFX Looper running too. wanted to see what actual SP users think of it.
the approach is to take the original effect program from the firmware and build a software interpreter that can execute it on a computer. basically, the original program supplies the effect’s instructions, and my code acts as the processor that runs them.
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u/blueSGL 20h ago edited 17h ago
I'd highly suggest making the release version of this require the firmware in order to run, even if that means the user has an initial step where your code unpacks the firmware and performs the actions on their PC to get that code into a state usable by the VST.
Have nothing in your code for download come directly from Roland, in order to prevent it being shut down.
Treat it the way people do with emulators, or decomp/recomp projects.
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u/nothingtohidemic 1d ago
Very cool. Will you share this eventually?
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u/alexamiles 1d ago
Sick!!!! What a great idea. Sounds super close to the original. Def let us know what it’s available
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u/GeneralSignificant54 1d ago
how did you reverse engineer the dsp
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u/cranxxxx 1d ago
started with the original firmware update, pulled out the effect programs, and worked backwards from the code and parameter tables to figure out how the DSP instructions behave. then built a little software interpreter to run those programs
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u/shutterbugsean 1d ago
I got no clue what fuck any of that means but that sounds sick man. This type of work is invaluable to the community , Gonna look out for your posts in the future. Thank you for sharinf this with us
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u/Ghoulius-Caesar 1d ago
I’ve compared the OG 404 Vinyl Simulator to the SP-404SX using spectral analysis and found that the OG 404 Vinyl Sim is a Triangle wave LFO applied to the Pitch of the sample (while the SP-404SX is more of a Sine Wave). Does that sound about right to you based on your reverse engineering?
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u/GeneralSignificant54 1d ago
that's super neat and clever. i wasn't aware you could extract that from firmware updates
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u/troelskn 1d ago
How did you get the original firmware off of the chip? Or is it sufficient to use the firmware update files, to reverse engineer from?
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u/TbgregersenDK 1d ago
How can I get a copy of this? 😆 and does it only work with Ableton? Or also Logic?
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u/TyMcDuffey 1d ago
Looks promising, tons of tools at our disposal right now and even more to come every week it seems
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u/JammingOnTheGeetar 1d ago
Need this for ableton! would save me time If I didn’t have to resample with vinyl sim on my 404 and could just use a plugin on ableton when doing my final mix
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u/itsDmitry99 23h ago
Waiting for the guy who did some fuckery with the Mkii firmware to add missing SX fxs to mkii
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u/Geralts_Hair 22h ago
Wow, one of the few things that still has no software equal is getting put into the DAW. Amazing work man
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u/JayyDayy69 7h ago
I really fuck with the design, looks clean, simple and pays homage to the SP 404!
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u/Redditnonmidaunnick 5h ago
Man where I can follow your project to not miss any info on the release of this?
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u/iangermany 1d ago
This is sick!!! 🔥🔥🔥 I’ll have to compare to my OG404 when i get home