Dual Frequency Oscillator

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  • Dual Frequency Oscillator
EUR19.68 price includes VAT
EUR16.00 price excluding VAT

What is this? The Dual Frequency Oscillator (or DFO for short) is a device designed to replace clock/timing oscillators in games consoles. By replacing the standard crystals with the DFO, we can slightly alter/tweak the system timings to our needs. The DFO allows not one but two different frequencies of oscillator to be used, one for PAL and one for NTSC.

Why would you want to do that? The main reason for doing this modification is to fix timing issues on PAL modded consoles when running in NTSC. Our article here explains it in detail, but in short, when you force a PAL console to output in NTSC, it does so using a timing oscillator designed for PAL not NTSC output. Instead of a timing close to 59.94hz (the NTSC standard) you often get one thatโ€™s way off spec, perhaps as far out as 59.2hz or more.

Why does timing matter? There are two reason why this matters. First of all, this will cause the image to appear in black and white when using composite video or S-Video connections. Secondly, more modern displays are less tolerant to this variation from spec than the old CRTs used to be. An off spec vertical refresh rate can cause the image to stutter, judder, have vertical lines/streaks across it or prevent it displaying at all.

What consoles does this work with? This version of the DFO is ideal for use in the Sony PlayStation. Itโ€™s also suitable for use in the Sega Megadrive. The version here comes pre-programmed with the correct timings for the PlayStation and Megadrive.

Where can I get fitting instructions? Currently, fitting instructions are available on this page. This page on German forum also has lots of useful information.

What if I want a different program on my DFO? To reprogram the DFO you require a programmer, we do NOT sell these just yet, but you can get the plans to build one, and find out more about the DFO by clicking here (English) or by clicking here (German).

If you require a different program in your DFO we can reprogram it before sending it out to you if you supply the required hex file.

Will you be stocking the other version of the DFO or the programmer? Maybe, this is still an experimental product and although it works great in the PlayStation, it doesn’t work in all possible use cases (in testing, it has proven not to work well in the Sega Saturn, for example).

Will you offer a fitting service? Yes, we hope to in the near future.

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  1. h1ghju1ce says:

    I’ll keep an eye out for your fitting service, would like this in my MDII ๐Ÿ™‚

    How does this work/interact with your switch-less region mod that you offer/install ?

    I’m assuming it makes no difference *how* the region is set because this auto detects and sets based on the output timing signal correct?

  2. Kevin Black says:

    This is super interesting!
    Would is work with the Playstation 2? I have a “chipped” modded PAL unit that it a little odd when playing import games and using my Framemeister.

    • BuckoA51 says:

      Not aware of anyone getting it working on a PS2 yet. The PS2 should be find playing PS2 games at either 50 or 60hz but PS1 games are problematic.

      • Kevin Black says:

        That actually completely makes sense! The games that I tried on my PS2 that didn’t work correctly were all PS1 games!
        This would be of interest to me installed in a PS1. Is is compatible with the slim PSone? ๐Ÿ™‚

  3. Damian says:

    Really interested in your fitting service for mega drive, hope you offer a switchless mod and oscillator service ๐Ÿ™‚

  4. Harrumph says:

    Any chance of you stocking the DIL14 version? Would be an easier install in MD as it’s a simple drop-in replacement…

  5. Revan says:

    I was looking in the link and noticed that borti posted something about having the DFO connected to the snes SuperCIC? Not that I understand German but the supercic comes with its pre built clock crystals so it isn’t necessary needed to use the DFO on the snes?

    Oh btw Bucko I’ve found some images for the superCIC soldering points from borti from, not sure if you wanna take a look and update the links.

    • BuckoA51 says:

      Thanks will do, the one I got was a little blurry. The SuperCIC for the 1-chip has its own crystal but the multi-chip one does not.

      • Revan says:

        Alright thanks for clarifying that, I wasn’t sure on ordering the DFO since I’ve contacted cybdyn systems concerning about the timing issues you had with the PSIO but they replied on fb saying that the DFO is only needed for composite video unless using RGB.

        I wasn’t sure if it is possible if they may have updated the PSIOs firmware for timing tweaks or not for PAL PSX?

        • BuckoA51 says:

          Really surprised they said that, no the DFO is needed on a lot of televisions to prevent stutter, torn frames or judder because the PAL PlayStation is so far off NTSC spec when running NTSC software.

          This isn’t something you can fix on the PSIO firmware, the oscillator is on the PlayStation’s main board, not in the PSIO.

          • Revan says:

            Yeah thought so, it just sounded like it wasn’t even a problem they had which was odd, but then again this was from their Facebook page so it could be someone who is just replying on their behalf.
            Bit of an off topic question for timings, I was looking up the timing for the n64 and I noticed there were a few pages on idicating that the PAL n64 with the ultrahdmi mod actually runs close to 61hz? Would this be a problem or not if the pal n64 is running past 60hz unlike the ps1 not reaching it?

  6. nam9 says:

    So… what info would you need to correct for a Neo Geo MVS?

    • BuckoA51 says:

      Good question, I’d like to see someone attempt that too.

      • nam9 says:

        If target vertical refresh is 59.94Hz…

        The Neo outputs pixels at exactly 6MHz. Each video line has to be a whole number of pixels, and each video frame has to be a whole number of lines (for non-interlaced display). In this case, there’s 384 pixel periods per line, and 264 line periods per frame. 6MHz divided by 384 gives a line rate of 15.625 KHz. 15.625KHz divided by 264 gives a frame rate of 59.1856 Hz. (Credit: SpamYouToDeath,

        ((59.94Hz / 59.1856Hz) * 24.00MHz) oscillator, ~ 24.3059MHz
        (Credit: mikejmoffitt,

        Could a 5v DFO with clock set to 24.0000Mhz and 24.3059Mhz be worth a shot?

  7. Octane says:

    Any chance these will be back in stock soon?

  8. Luke R says:

    will this DFO work with either the master system or the master system 2?

  9. Riptide666 says:

    Any news on when these are likely to be back in stock?

  10. Luke R says:

    Does the DFO work for both the model 1 and model 2 mega drives?

  11. Donovan says:

    Is this compatible with the switchless mod D4S for the Sega Megadrive? I mean, connecting the frequency selector of the DFO to the 50/60Hz pin of the PIC16F630 to have true NTSC and true PAL just using the reset button.

  12. filip meyers says:

    hi,when will this be back in stock,i come here every week,nothing in stock.

  13. Bart says:

    Hi! Very much interested in this one.
    Why not offer a back-in-stock email notification thingy on your store website? Saves me time to keep on checking if back in stock, offers you customers directly when new stock comes in!

  14. Stan says:

    When will this be back in stock?

  15. Tim says:

    Is dual fesuency oscillator needed for pal ps1 when using rgb with framemeister or the ossc?

  16. Andres says:

    Is this going to be on stock anytime soon? If not, where can I buy one? Thanks!

  17. Peter says:

    Do you have any plans to restock these?

  18. Nick says:

    Only just been looking into this type of mod. Would like to get it done, but don’t understand most the stuff. Seems the pre-made part has been out of stock for a long time ๐Ÿ™

  19. superflat says:

    I’m interested in getting one of these for my Megadrive model 1 and PS1 model 7501. What would be even better would be if some genius could come up with a switchless MD mod combined with the DFO on one board with decent instructions (if such a thing is possible). If I understand correctly, you said you are working on a similar version of this for SNES combining switchless mod, de-jitter and DFO. I’m an amateur so multiple interacting mods scare me a little so if these can be consolidated to a one-stop PAL -> NTSC solution I think they’d sell really well! ๐Ÿ™‚

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