NES/SNES De-jitter Kit

EUR23.55 price includes VAT
EUR19.15 price excluding VAT

Does your OSSC work perfectly with your television, except when you try to use your RGB modded NES or SNES? Due to a quirk with the NES/SNES hardware design,  NES and SNES consoles generate a ‘jittery’ sync signal in 240p mode. This makes their signals challenging for digitizers which use it in clock generation, and especially for devices like OSSC, where the output clock is derived directly from the sync signal. Not every HDTV is affected by this quirk, but if your other consoles are working fine while your NES or SNES has issues, chances are it’s the jitter bug.

By installing this upgrade, your NES/SNES consoles sync signal will be corrected, meaning it will be compatible when used with the OSSC and any HDTV (assuming your HDTV is compatible with the OSSC in the first place, of course).

Note – The de-jitter mod is not applicable to PAL consoles (unless you have installed a SuperCIC board) and would be dormant if installed in a stock PAL console.

We can now supply the boards with NES or SNES firmware. Simply choose the desired type from the drop down menu.

Installation instructions

For installation instructions and more information, please visit the Github page here. Please note – This is a complex mod and requires some familiarity with the internals of the NES or SNES console. PLEASE only order if you are confident that you can fit the part. Community based technical support is available in our forum here, but unfortunately we cannot provide technical support with DIY installations, nor can we offer refunds for parts damaged due to misuse or incorrect installation.

Thanks to Markus Hiienkari and the retro gaming communities for making this mod possible. This is an open source mod, if you are interested in building your own board, click here.

If you require a fitting service for this part into your Nintendo SNES/Super Famicom console, click here. A fitting service for the NES version of this mod is coming soon.

Customer Reviews




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NES/SNES De-jitter Kit
Average rating:  
 2 reviews
by Michael Zander on NES/SNES De-jitter Kit
Works Great/Easy Install on SNES/ NES a Different Story

I purchased two of these kits: one for my RGB-modded SNES Jr., and another for my RGB-modded NES Top Loader. The kits shipped quickly to the US, and installation instructions are well detailed on Retro Mods Wiki with pictures and coverage of each NES/SNES revision.

As far as soldering this into place, it's not the easiest thing for beginners, but if you can strip and tin wires then you should be able to follow the retro mods wiki installation guides just fine. If you live outside of Europe and want to save on shipping your console to the UK, this is a doable, low cost alternative to the installation service.

On SNES, this thing works like a charm as soon as you install it. The board is pre-flashed with the requisite firmware, and it looks great on all my digital displays through the OSSC. Additionally, it works perfectly on my capture card (Magewell HDMI Capture Pro), which was my ultimate reason for buying the kit.

NES is a different story. The default firmware on the board does not seem to work with the NES (while I still get all three color channels on my Sony PVM, I do not get sync at all), so you must download a special "NES Fix" firmware from Marqs' GitHub and flash the board over JTAG. While the GitHub guide makes this sound straightforward, simply finding an FTDI FT2232 JTAG USB debugger is an exercise in patience in itself, seeing as all the compatible devices listed on OpenOCDs websites contain dead links and are seemingly unavailable for purchase on Amazon or eBay. Furthermore, OpenOCD itself is confusing to use and requires knowledge of command line inputs. It does not seem to like either of the USB JTAG debuggers I could find (which weren't cheap) and refuses to identify the dejitter board.

My point is that unless you already have the hardware and software to flash the board, AND know how to use it, I STRONGLY suggest holding off on buying one of these for NES until a pre-flashed "NES Fix" version becomes available for purchase. If I had known it would be such an ordeal to update the firmware, I would've only purchased one board for SNES and waited for such an "NES Fix" version to come out.

Thanks - we're working on making the NES Fix version available next batch.

by Samson Wick on NES/SNES De-jitter Kit
Compatibility is Rock Solid

One day this may be a plug-and-play solution, but for right now it is not. Programming the CPLD with the latest firmware is not a casual activity, and installation instructions for the NES were somewhat nascent. That being said I would rather have to figure the last 10% out for myself than wait another year for a fix until it was refined. I was eventually able to figure out both how to update the CPLD with what I had on hand and how to properly prep the NES-001.

As far as function goes, it has been rock solid so far. The first thing I noticed when piping this through the OSSC is that the refresh rate appears on the display as 60Hz instead of the customary 59.97Hz that I'm used to. The NES now works in OSSC 5X on every TV in my house without any special settings or anything.

You're right, instructions for NES are very much a work in progress. In future I'm hoping to offer the unit pre-programmed for either NES or SNES.

If your country is not listed as a shipping destination please contact me, I may be able to sort something out for you!

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  1. Peter says:

    Can this mod be applied to a 1-chip PAL SNES?

    • BuckoA51 says:

      Generally it’s not needed for PAL games so would only be appropriate if you had a SuperCIC installed too.

      • Peter says:

        I have a simple 50/60hz +region change DPDT switch and RGB sync on luma cable. Should I:
        1.get csync_i from S-RGB
        2.route csync_o to pin 3 of multi av connector, instead of 12v
        3.connect MCLK_o to NTSC switch position on my mod
        4.get a ntsc snes cable?

  2. cheesemaun says:

    Now I can do 5x linemode with my OSSC and my SNES. Even 4x seems more stable. (non-1chip model)

  3. Pablo Romero says:

    Hi, will there be a restock this month??

  4. ardarvin says:

    Is this product relevant for original unmodded (large) SNES consoles, where RGB is from a SCART cable?

  5. Hi, is there any update on when this will be available again? I’d love to get my hands on a NES and SNES board 🙂

  6. Bart says:

    Hi, Am I correct in understanding this is only for NESRGB modded consoles?

    I own an AV-modded Famicom, and would like to get rid of jitter that shows up regularly. Is this a fix? And if not, any other mods available to solve this problem?

    • BuckoA51 says:

      It’s for NES RGB yes. What exactly are you seeing on your console?

      • Bart says:

        It looks like jitter, shaky screen. Sometimes on the whole screen, best visible on the top part though.

        I did the av-mod, image looks great, testing with Rockman 1. Usually starts out fine, but at specific parts in the game, the image becomes jittery and stays that way. Unplugging the video cable, wait till tv turns black and insert cable again, solves the problem till it appears again. Like it’s losing sync, re plugging the cable seems to reset it or something.
        Different tv’s give different results (different parts in the game, different sync issues), but problem does seem to occur on all tv’s I test on.
        Tried different cables and grounding, then built down the mod and built up again part by part to test, all seems fine. Even tried different carts of the same game to be sure.

        Then used my original NES with the same game through the original composite out, and see exactly the same jitter there, actually much worse. So I’m pretty confident now it isn’t my mod that’s having problems, but the problem is with the consoles themselves.

        When searching for NES/Famicom jitter, I always end up here, or on that shmups forum topic. So am wondering if this board could solve it, or maybe if the DFO board could be the solution.
        Cause I understand that this jittery sync is a known Famicom/NES problem, so assume it does usually appear on non RGB modded consoles as well?

  7. Bart says:

    Ok.. So I understand that Retrotink 2X also does some sync things to solve jitter problems. And since I’ll probably need to convert composite to hdmi in the future anyway, it might be the best choice to try that out first!
    Thanks for your replies.

  8. Andrew Kepic says:

    Hi. When I run my modded SNES Jr. and RGB modded NES toplader through the OSSC to my monitor, my monitor constantly loses sync and fades to black. This occurs when I output the OSSC using optimal video modes. Will this kit help to correct that? Thanks.

  9. Mike says:

    Can this mod be used with HD retrovison’s component cables on the SNES? Or using component output on an NES?

  10. john lawless says:

    Can this be used on a famicom with a rgb mod inside or just nes conaoles

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