Gameboy DMG-01 Pitch Modification

gameboy_dmg_pitch_mod_1.JPG

As promised, here is a GetLoFi take on modifying GameBoy DMG-01 with pitch control via the LTC1799 Precision Module from the GetLoFi Shop. The process to replace a fixed 4.19 MHz crystal with a variable digital clock is pretty strait forward, however we will not be responsible for any damage to your hardware, so please do this at your own risk!

ltc_1799_boards_smaller.JPG

First you will need some assembled LTC1799 modules from the shop. You will also require an original Nintendo Gameboy, note that it is possible to modify Gameboy Color and probably Pocket however Gameboy Advance and SP currently do not work.

[youtube]http://www.youtube.com/watch?v=yu7QKU_UAbk[/youtube]

Open up the Gameboy by removing 6 screws and gently remove the top half by unplugging the ribbon cable. To make room for the potentiometer take out the speaker by clipping yellow wires. Carefully drill an appropriate size hold in the speaker grill from the inside. The legs of the potentiometer may need to be bent upwards, DO NOT use a hard surface to do that, the entire assembly may snap off! Use pliers to gently bend them. Attach one wire to the center and one to an outer leg for connecting to the pads on the LTC board. The value of the potentiometer may vary depending on your application. For drone-like sounds a 500k or larger may be good, but if you just want ~50% BPM adjustment try a 50k.

gameboy_top_half_potentiometer_hole.JPG

To wire up the bottom half start by cutting the lower trace of the crystal, no sense in desoldering it, this also leaves the option to restore the connection. Take a closer look at the diagram before doing this. DO NOT cut any other traces around and check to make sure its completely cut with a continuity tester. Connect the output of the LTC Module to the upper leg of the crystal as indicated in the diagram. This is where the clock signal will be injected into the CPU. Use thin wires cut to length, if they are too long or too thick closing the case will be a problem.

gameboy_wired_up.JPG

Next connect to the Ground point to the LTC Ground pad, then Positive point on the DC Jack to the +5 volt pad on the module. Refer to the above diagram once again. The final step is to install a Trim resistor on the LTC board. Cut the trace between two unoccupied square pads and solder in a 10K resistor. This will prevent the Gameboy from crashing when the CPU frequency is too high. Reattach the top half of the case via the ribbon cable and turn the system ON, because the speaker was removed you will not hear the tone unless its plugged into an amp. Adjust the potentiometer to make sure the clock modification is working.

gameboy1.JPG

Once everything checks out, neatly arrange wires and slide the module into the groove on the right side of the battery case. Make sure there are no wires right under the potentiometer or the system will not close. Reinstall the screws and test the system, at this point you are done!

[youtube]http://www.youtube.com/watch?v=HJOs3zOlHV8[/youtube]

More modifications will be posted very soon including: Pro Sound and Backlight. Please Stay Tuned!

47 thoughts on “Gameboy DMG-01 Pitch Modification”

  1. hey i love this idea. i want to ask a few questions though…

    how difficult is this to do? for a 12 year old enginneer/ ham radio operator.?

    can it be done with a game boy color too?

    how long does it take to put together?

    are there specifice instructions ( more detailed)?

  2. Well there are 3 wires to solder to the Gameboy, if you can solder you can do this.

    Yes, it can be done to Gameboy Color. I don’t have the schematic posted, but the process is similar.

    The first time you do this, maybe an hour total.

    The above instructions are pretty specific, take a look at the video if you need more help. Read carefully, its all there.

  3. o.k.

    you see, at first i had alot of questions and then as i looked arond more and more i found the anwsers.

  4. Got it working after some messing about due to my LTC1799s looking somewhat different to the ones pictured, maybe I got an older version when i ordered some time back? Anyway I figured it out without too much trouble.

    One thing tho: this mod does not work when running the GB off the DC adaptor! Only with batteries (or in my case adaptor croc clipped to the battery points as I can’t find any fresh AAs!) Anyone have any idea of alternate +5 and/or ground points so the oscillator module can run however the GB is being powered?

  5. do you still need to use game cartridges to make the sounds?

    i see you’re using the camera so just curious.

  6. Yeah, all this does is makes it possible to speed up (slightly) or slow down (greatly) the overall speed at which the gameboy runs, thus changing the speed and pitch of whatever sounds it is making, whether it be game sound fx/music, or music software cartridge such as LSDJ or the dj ‘game’ sequencer in the GB camera.

    Here’s my bricollage attempt so far, housed the pitch knob in an external box (broken behringer pedal casing), might also add pro sound mod in there with 2 1/4″ sockets, more convenient than fiddly stereo jack. – http://www.flickr.com/photos/timdrage/3529552124/

  7. The diagram has just been updated. Apparently the +5 volt point I was using is not switched, so the module will run the batteries all the way down. And prevent the DC jack from working correctly.

    Please use the new diagram and steal the juice from the 4 wires connects on the side of the board, the RED wire to be more specific.

  8. awesome, trying to do the same mod to a gameboy color, getting a little overwhelmed by the variation of the PCB. They seem quite different. What am I looking for to identify the trace on the board i am suppossed to cut? and what is the point that the “out line” will be connected to. Any tips would be appreciated.

  9. Actually you don’t need to cut any traces. Try connecting to the crystal leg of the big square thing on the circuit board. Its Black with a white bottom and there are 4 wide-legs coming out of it. Should work just fine.

  10. hey! awesome stuff!
    i am using a nanoloop 8bit audio cartridge for GBC and would like to buy the LTC1799 modules from your shop, to modify my old game warrior.

    Now… my question: I have seen that the pitch does affect the display (refresh rate etc.) but is it possible to keep the normal function when the poti is set to zero or max? Do i “kill” my gameboy with this or is it just a matter of using the modification?

    Greetings from Germany, hope to get an Answer soon 😉

    Take Care, Max.

  11. The display will look just fine when the pitch is higher. You can add a Zero setting by disconnecting the LTC module, more on that will be posted soon. It is not necessary to cut the trace to the Crystal.

    The Gameboy will be just fine.

  12. im liking this more and more i look at it 😀
    this would be my first cicuit bend, along with making a GetLofi amp with my old GB carry case..

    are there any other mods besides the pitch pot, backlite, and prosound?

    is there a mod where i can pause or anything like that?

  13. is there any other space in the dmg’s body work where i could put the speaker?

  14. Wow! that was easy… now to figure out how to connect an old dmg model to a gba sp running nanoloop 2.3…

  15. this looks pretty cool 😉 question: did you make a tutorial for that GBC you did this on? i saw the demo on youtube, and i really want to try it out =] thanks man -[

  16. You could probably move the knob on the left side, however you will need to trim the Headphone output board to make space. If you are planning on doing the Pro-Sound mod that should be just fine.

  17. Hi, I just installed the LTC Module in my gameboy…. inserted batteries, inserted nanoloop and boom…. byebye nanoloop, it chrashed… when I put in Tetris it works fine the LTC Module…. thanx alot for ruining my nanoloop 1.3 wich is not for sale anymore

  18. Hello Ben,

    It is unfortunate about your Nanoloop 1.3 crashing, to be honest that is the FIRST time I’ve gotten a report of that happening. The mod worked fine for me with Nanoloop 1.2 which I have. I think it was a freak accident.

    You can probably email Oliver, maker of the cart and ask to have him Reburn it for you. We can also refund your kit price. Still its a bummer and I would be pissed as well.

  19. circuitmaster, thanx for helping me out
    I did as you told me, I sent an email to oliver (nanoloop) and he came with the following solution, and it works,….

    – start game boy
    – keep a+b+select (but not start) pressed until nanoloop logo disappears
    – wait a few seconds until it says “ae”
    – press b
    – sequencer appears
    – restart game boy

    After this procedure, bank numbers may be shifted (bank 0’s content appears in bank 5, bank 1 in bank 6 etc). Be careful not to press a+b+select+start because this will reformat memory.

    The flash memory on the cart requires specific timing and will probably not work with an underclocked Game Boy. It should be OK to overclock, but I’m not sure either.

    so problem is fixed, nanoloop works fine with LTC button and its cool!!!

  20. This might be kind of a dumb question, but is it possible to return the gameboy to the original pitch with the knob, or do you just have to kind of approximate?

  21. Its possible to install a simple disconnect switch for the LTC and that will bring the Gameboy to the Normal Pitch. Otherwise you can also mark a point where it sounds Normal and just approximate by ear.

  22. How would you go about putting a switch to toggle the potentiometer? I’ve seen a few with those on them, and it seems pretty useful to have

  23. I’m trying to install the LTC1799 into a gameboy color. So far I’ve figured out that there is no trace that needs to be cut, and that I need to connect the out to one of the legs of the chip labeled 8388 KSS OCF (the black rectangle with the white bottom).
    But I’m still having trouble figuring out where to connect the 5+ and the ground, since the gameboy color and DMG PCB’s are so different.

    ground to the – battery terminal, 5+ to some random spot on the DC jack?

  24. Hey Zack,

    I will be uploading the Gameboy Color instructions shortly, actually did the modification and it turned out really well.

    You are correct, no trace needs to be cut and yes the 8388 IC is the crystal. Either of the two legs on the left side works fine.

    Use the actual power switch as a power source. The ground can connect to the housing of the switch and the positive should be the pin right in the middle.

  25. Hi,

    I’ve installed everything as shown in the diagram (or at least I believe I have), the mod seems to be working, but even on max the Gameboy is running at only a fraction of the speed. Do you have any ideas what is going wrong?

    Thanks

    Andy

  26. hi i wanna buy this but i want to put it in a gameboy pocket, but i dont want to take out the speaker…i have the gameboy powerpak modded with the nintendo 3ds nyko powerpak battery…i know i could fit this there inside the powerpak but i need to know the the clock pinout for the gameboy pocket as i cant find out where, could someone help out? thanx in advance

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  28. can you guys show how to make these just using the components or something, I want to do it, and I would gladly buy it from you, but everything has been sold out for a while.

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