GameBoy Color 8-bit Visualizer Mod by Tekmann




Introduction: GameBoy Color 8-bit Visualizer Mod by Tekmann

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In this mod I will guide you how to install a 8-bit Audio Visualizer (Quantum VJ) into your Gameboy Color (GBC)!
This is a quite advanced mod that incorporates cutting holes in your precious GBC shell. Proceed with caution!

Check out this video if the finished mod to get a better idea of what it does ;)

In this guide I leave some basic stuff out like how to dismantle a GBC and soldering basics. This you can learn in many other guides, and frankly...if you havent dismanteled a GBC before you shouldent do this mod!

Be sure to read through all steps in the mod before starting so you get the whole picture and understand the different steps in the procedure.

I have a couple of other mods in my GBC so there is quite many wires in the mod images of my unit. Dont be scared by this! :) Complete mod list for this GBC unit: Frontlight, 8-bit visualizer, Prosound
3,5mm & Internal Prosound, Bass enhancer, Noice cancel, Internal leds.

Please please take pity over my English, Swedish is my native tongue but that wouldent do you guys any good ;)

Equipment needed:
Quantum VJ-kit (order from
Soldering stuff
Thin wire
Cutting knife
Nintendo tri-wing screwdriver
Rubber eraser
Piece of cardboard
Small on/off switch with screwholes (optional)
Small screws for OLED
Hot/melting glue (preferably)

Transparent tape

Step 1: Order Quantum VJ

Order one piece unassebled Quantum VJ from

Hell, order one assembled as well, these buggers are neat!

Do not buy the new version with a built in microphone, the mic is not needed since we get our input internally from the GBC. Yes this is good stuff directly from Russia, so it will take a month or more until you receive it. Price approx USD 25 inc. Shipping.

See the pic of how a assembled Quantum VJ looks like.

Sweet, you received it alteady? Thanks mr Zolotov! Lets proceed to the next step then :)

Step 2: Schematics

When you have received the delivery its time to figure out how to put stuff together.
This is the schematics for the original design (see pic): Just to be sure, check included schematics in your Quantum delivery if there has been any revisions in newer versions of Quantum VJ)

Firstly I think that it is a good idea to check that the components are working before putting them inside your GBC. Take a cardboard box and tape the components to it, then draw the connections with a pen. (see pic) To test things out, follow the original schematics so you can use a CR2032 battery for power and the 3,5mm line input to get a signal. Later on, we will not use the battery or the 3,5mm jacks. The left jack in the cardboard image is the input and since we are not going to use the output you can remove this jack directly (at the lower right in the cardboard image). Look at my cardboard wiring scheme how to wire the jacks if you are unfamiliar with these.

In the cardboardimage I misplaced the on/off switch. It should ofcourse be between the + on the battery power and everything else that is wired to + current so that nothing gets any power unless the switch is turned on.

Step 3: Quantum VJ Circuit Soldering

Solder the parts together according to the schematics & my cardboard :) It can be hard to figure out what is up/down on the chip, but there is a small shallow hole made in the top left corner. This is how you find your orientation!

After soldering is done -switch it on! I found that 10-15cm length of wires was a good choice to fit it into the GameBoy later. Use a bit longer wires for the on/off and mode switches since we will put them on the other side of the gameboy. The contacts on the OLED screen are labled on the upperside of the screen. Solder on the backside.

After you have checked that everything works, mark up the wires leading to the screen, 3,5mm jack and battery. Then cut off these wires. Snip off the contact legs on the OLED screen so they are quite short, otherwise they will press on the upper GBC circuitboard when you insert it in the front shell. We will not use the batterysocket or the jacks at all. The OLED screen cables will have to be led through a hole in the frontshell before soldering. The included power switch has not got screw holes so I would advice to buy another small switch that you can screw into your shell.

Step 4: Plan!

Time to figure out how to place the circuit in the gameboy! This was my original plan (image)

I ended up with placing the mode switch on the right side instead of the left as in the image. So my advice is to put it on same side as the on/off switch we are inserting (right side).
Now take apart your gameboy, unscrew the outer shell screws and the ones in the battery compartment (6 pcs tot). Also unscrew the three shorter screws that holds the front shell onto the circuitboard. When you screw these in again, be sure to take these three shorter screws again and do not mix them up with the 6 longer screws. Also take out the powerswitch, IR cover and start/select button so they do not fall off while you are modding and disappear.

Step 5: Cutting Holes in Your Shell

Now we will cut holes in the shell for the power switch, mode switch, OLED screen and make some extra room inside the GBC to fit the chip & cables.

Use a cutting knife to cut holes for the power and mode sw. Cut a smaller hole to start with then trim it to the right size so it gets nice and tight. This takes time... Dont cut yourself and dont curse! ;)

The power sw is the long one in the pic and the mode sw. Is the square one. The mode swith has not got screw holes, so we will pry out the legs and insert it from inside, then we will cut a rubber eraser to place behind it so the switch gets stuck properly ;) You will have to cut away some of the plastic between the battery compartment and the outer shell to fit the switches & route the cables. Drill holes for the screws if you chose a power sw. with screwholes. On the other side (left) of the battery compartment you need to cut out as much of the "extra" plastic connecting the batt. compartment with the outer shell. Here we will fit the Quantum VJ chip and most of the wires.

Now, place the OLED screen in a spot on the front shell that you feel comfortable with so it doesnt obstruct button pressing or get in the view of the gameboy LCD. This is where we will fit it!

This OLED placement worked good for me (see pic). Now, mark out where you want to fit your screen on the shell. You will have to cut out a hole for the OLED connection legs to go through the shell. Mark out where the screwholes to the OLED are and drill small holes for the small, shallow screws that you have found (not included in the Quantum kit). You will also have to hollow out the GBC at two small areas underneath the OLED to make room for the small surfacemounted components. Without these hollowed out areas the OLED will not be able to lay flat against the GBC shell. On this image I marked out the areas needed hollowing with a black marker pen. With the placement I chose I also had to trim off about 1mm of the shell edge towards the GBC screen protector to create a good fit.

Step 6: In With the Gear!

Now insert the Quantum circuit into your GBC. The chip & resistor on the left of the batterycompartment, the switches on the right and the cables from the chip to the OLED coming from left (chip placement) and leading through the hole you cut in the front shell. through the newcut hole in the front. You can route the wires from the chip to the switches above or underneath the batt.compartment. I did it above since I had so much other mods underneath. Its many wires that has to be in a specific placement within the shell, so I tape them into place with transparent tape when I have to :)

When you have placed all components and cables where you want them, try to put the GBC "sandwitch" together and press all cables sticking out inside the shell. Check that everything fits before starting up with the soldering. Put tape around all conductive parts like the resistor so it doesnt short out your gameboy. Does everything fit? Good, proceed to the next part.

Step 7: Solderingtime

Now we need to locate an Audio input that the Quantum chip can generate Visuals from. The classical prosoundspot at the vol. pot (see images) is the best place for this, so solder one wire at the Left or Right connection point and route the wire downwards and solder to the audio input wire that you cut off from the jack previously (Yes you should have labeled this). If you already prosounded your unit you can just solder to L/R of your prosound output instead. If you are worried about potential unbalance between L/R output you can try taking output from both channels to the Quantum chip input. But I havent noticed any change in balance when using the Quantum VJ with one channel input so this is probably unnecessary.

(Thanks lowgain audio and 56k death for the prosound-images)

To get power to the Quantum we need to solder to one of the battery +/- points on the board, I use the upper side of the circuitboard and the solder points labeled BT+ and BT- that are located above and beneath the A/B button "presspoints" (see image). Solder the + wire that you cut off the battery previously (which leads to the on/off switch) to BT+ and solder the ground wire (-) that you also cut off the Quantum battery to the BT- terminal. Quantum VJ runs natively with a 3v CR2032 battery, same voltage as the GBC so no additional resistors is needed to control the voltage here, nice!

(Thanks Mark Bowers for the circuitboard pic)

Ok, everything but the screen is soldered!

Route the four wires to the screen through the front hole that you cut previously. Look at the labels at the cables (that you put there earlier) so you know what wire to solder to what terminal. The terminals are labled at the upper side of the OLED. Solder!

Step 8: Final Touches

Now try inserting the OLED in the hole/carvings you made in the front shell. Check that it fits well and carve some extra if you need to make it lay flat and get a good fit. Now we fixate the OLED on the front shell. Put a daub of melt-glue beneath the upper backside of the OLED instead of screws. (or other glue you feel comfortable with that has some cushioning effect) Be aware- meltglue cures very quickly!
After glueing you can screw the two bottom screwholes of the OLED.

We only screw the two lower screwholes in the OLED since the upper two are located above the GBC screen cover and could damage the LCD underneath.

Now it should be stuck :)

Almost done with the mod...

Everything is now soldered, so try putting the GBC together roughly and insert batteries to check that everything is working before closing the GBC up. Turn on the gameboy and the Quantum powerswitch. Check that the Quantum mode button works. The Quantum VJ should start blinking even if you have no audio input yet. Try cyceling through the different display-modes with the mode button.
If everything works you can remove the cable-lables that you put on earlier, this will help you fitting everything within the shell ;)

If it doesnt work...check your soldering!

Put the GBC together and tuck those cables in with tweezers. When screwing the unit together make sure that no cables are in the way if the screwholes, the screws can potentially rip apart cables otherwise when screwing the shell together... And dont forget to put in the GBC powerswitch/IR cover/start & select buttons. That stuff will drive you crazy if you have to open it up again ;)

Step 9: Finished!

Insert batteries. Now turn off the lights in the room, insert your LSDJ cart with your best song and turn on your cool new GBC mod! Partytime!!

Dont hesitate to contact me if you have any questions, tekmannmusic[at], or send me a message on Facebook:

\\ Best Anders Ekman a.k.a. Tekmann

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    2 Discussions


    4 years ago

    This looks great - very nicely done!!


    Reply 4 years ago

    Thanks man!