Volca FM Unofficial Firmware Update Adds Velocity Sensitivity & More

pajen has introduced an unofficial firmware that adds new features to the Korg Volca FM, including velocity sensitivity, and fixes some outstanding bugs. This video, via ranzee, demos the changes.

The original alternative firmware added velocity sensitivity. Here’s what’s new in the latest version:

New features:

  • Global setting 9 : enable/disable velocity on MIDI notes IN
  • Global setting 10: Yamaha compatability/Korg proprietary single patch import/export
  • Global setting 11: Patch change notes on/off


  • CC 1 : (Mod wheel) assignable via CC 91, defaults to Pitch Mod Depth
  • CC 85: Chorus on/off. value -64 off, value +64 on.
  • CC 86: Chorus stereo width, 64 is default
  • CC 87: Chorus speed, 64 is default
  • CC 88: Load patch, value 0-4: patch 1, 5-8: patch 2 etc up to 127
  • CC 89: Load pattern, value 0-8: pattern 1, 9-16: pattern 2 etc up to 127
  • CC 90: Tempo divisor, value 0-31: 1/1, 32-63: 1/2, 64-95: 1/4, 96-127: 1/8 (!)
  • CC 91: Mod wheel mapping: decides what MIDI CC mod wheel should map to. Example: value 42 sent on CC 91 – Mod wheel now controls Modulator Attack

LFO fixes:

  • S&H 256x scale error
  • S&H update logic error
  • LFO sign error (saw up/down, square polarity)
  • added filtering to remove digital pop on discontinuous LFO

Note: The update is not currently available to download.

If you’ve used the update, leave a comment and share your experience with it.

20 thoughts on “Volca FM Unofficial Firmware Update Adds Velocity Sensitivity & More

    1. True, but it’s still good to know about. There will be more updates in the future maybe. This guy pajen is doing absolutely incredible and interesting work.

      1. For sure, this is pretty awesome. I just wish Synthtopia had picked it up a little earlier but I’m sure it won’t be that hard to find. I’m running out of reasons not to own a VFM at this point,

  1. Forgot to say Korg also deserves props for embracing/tacitly accepting accepting open source as opposed to the ‘no user serviceable parts inside/don’t you dare mess with our intellectual property’ attitude of certain other manufacturers.

      1. I think he’s saying that since they are not filing a lawsuit against this guy that is a form of “embracing/tacitly accepting”. I’d put it on the side of tacitly accepting, or perhaps being unaware, or deciding (correctly) that since he is not redistributing Korg firmware and instead is distributing it as a patch to firmware which you legally download yourself from Korg, that there’s nothing illegal about it and it doesn’t violate their copyrights. If he published the patched firmware though they’d probably initiate legal actions against him, IMO.

        Korg’s been celebrated for putting easter eggs on Volcas such as extra mod points and secret features that you can only find by opening them up and messing with the circuit boards. That’s a form of openness, though it may have been a compromise between the designer who wanted these features and management which didn’t. I suspect it’s more of a designer sneak-in like most easter eggs are and not a corporate policy.

        To be really open, Korg should put the actual firmware code up on github or such. However that would probably cause problems as the most likely outcome would be people bricking their machines and complaining, or deluging Korg with help requests of how to compile firmware images for various processors. Korg management also is quite likely to believe the firmware contains some sort of trade secrets and nix plans to release the code, though almost certainly it doesn’t.

        Current situation may be ideal. The firmware loader doesn’t encrypt anything, it’s a straightforward image that can be disassembled and analyzed by the sufficiently motivated and skilled hacker. Those without the skills are thus less likely intrinsically to brick their machines and complain, and anyone bricking by doing firmware patches already knows that that’s a risk and anything that happens is their own fault.

        Also from a legal perspective it is best Korg have nothing to do with this project. If Korg analyzes the changes and adds them to their own code then the hacker has a case of copyright infringement against Korg. No one at Korg can analyze or touch this patch because it opens a legal can of worms. If you implement something after looking at a competing implementation, you are dirty and liable. When implementing a copy of something else you have to maintain a clean room where no one working on it has seen the other (ip protected) implementation. The hacker would have to put the code in the public domain before anyone at Korg could safely look at it.

        1. Hm, Jocko’s post above of Ranzee’s repost of allegedly pajen’s update is the patched firmware update, so Korg actually could issue a takedown for this if they wanted to, and I was wrong that he was releasing a patcher and not the patched firmware (I suppose due to the complexity of FSK decoding, patching, and reencoding the original). The time-limited release method that pajen’s doing though perhaps is an attempt at auto-takedown.

          Also, only just noticed that among the new features is that the Volca is now fully multitimbral, which is a pretty crazy useful new feature. Every note can be a different patch, just send program changes ahead of every note you want with a different patch. He did this by disabling the previous behavior of the Volca which was to do an all-notes off when receiving a program change.

        2. The update has been out a few days, would you expect a takedown that quickly? Usually it takes some time for something to get popular. Leaving out things like midi-out but leaving points are hardly ‘opennes’, rather a lack of features you’d expect from their products at those price points.

          What would be ideal from a legal and moral standpoint is if Korg would fix bugs in their devices, rather than continue to release new stuff. : | Instead we have to wait for a custom firmware. Thank god it exists, that LFO fix is a must & the lack of midi-in velocity was inane.

          Also the idea that the hacker could sue Korg if Korg adapted the fixes is completely insane and completely impossible. Are you doing okay? I don’t think you quite understand clean room design.

    1. Korg doesn’t deserve anything. You pay for what they make and the FM not responding to program change messages is not a bug, but one of Korg’s usual feature deprivation policies on their cheaper stuff, so you keep paying more.

  2. Wish there was an update/hack for the Volca Keys to support
    – sequence transpose
    – sequence step mute without skip

  3. This shows how much korg cares about their community. Sadly to see that such a firmware update came not from korg 🙁

  4. I’d say ‘Accept the ever-shifting world of left-field patches and ride them until they pop.’ Every device has its own life-span like a dog. Enjoy them while they’re up & running. This new firmware is a smart step ahead for an already impressive synth. Part of this world involves, um, pimping your ride. Larry Fast hot-rodded all five of a Prophet-5s voices so that each one had its own output, which he could then fuzz-box separately. This is just the modern equivalent.

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