There's been a project on reverse engineering the Alesis MIDIVerb (the first one—and by extension the MIDIFex) for a couple of years now. As of today, the project has gone completely open source! Great if you want to research more on it, or build a plugin emulating the original (hope one that's well maintained pops up soon).

 

Sounds clickbaity. Well it's the emulator that went open source not original Alesis DSP code which I believe is long lost.
But thanks for the notify I remember there were some videos on synthech.com

 

Last edited: Jul 17, 2025

Anybody find the MIDIFex ROM? MIDIVerb ones are fairly easy to find, not had any luck with the Fex though.

 

How about these https://www.reddit.com/r/synthdiy/comments/14u1cr3/midiverb_midifex_eprom_mod/

 

Requires requesting access to the files, I'd rather not for now!

 

verb2.rom anyone?
I got others tho, honk if you have one!

 

Was able to find the roms and test in MAME quickly. I did not test audio, but if it reports it working (it does), then it's working. This would require routing audio out of your daw, and back into your DAW via "VB-CABLE" or the like. This whole process kills the vibe, but you could save a song with MIDIverb ready to go with everything laid out so not to have to think about it. ADMIN can I say anything about the website I got the roms from? Thx. They were not hard to find. Google did it.

 

Last edited: Jan 14, 2026 at 2:15 PM

Want more sexual chocolate?

 

I have one question — why MAME? Why wasn’t it implemented as VST plugins instead? Someone clearly spent a huge amount of time and effort on this, but why? It’s incredible what goes on in other people’s heads…

 

VST3 is available:
https://github.com/thement/midiverb_emulator/releases

NM. I just checked and it isnt working at all.

 

Last edited: Jan 14, 2026 at 10:38 AM

Yes, sexy indeed! )

 

Hi,

used to own one, my very first Synth but gave it away. Got myself a CZ1 instead and still use some of its sounds.
Where can I get this one?

 

baby steps is my guess. Some people see it as archival, not artistic at all like we do.

 

You need MAME https://www.mamedev.org/release.php

You need roms. Those are pretty easily googleable.

Someone needs to do a non schitzophrenic tutorial in a normal speaking voice and no mouse pointer conniption fits.

 

MAME folk are more concerned that they emulate systems as accurately as possible. Things like usability come a distant second. That it can do this (or play games) is a side effect.

But if they didn't care about emulation accuracy the project would've not been as good as it is.

 

https://dbwbp.com/index.php/9-misc/37-synth-eprom-dumps
This page does NOT contain the required ROMs — only other versions of the dumps. Where did you find them? Please let me know.

 

Working fine for me. Win10/x64/Reaper. Sounding good!

 

Does the VST require a .rom file?

 

Nope (why didn't you just try).

This one doesn't either, but only works correctly at 48kHz and has no feedback control: https://github.com/ErroneousBosh/BarrVerb