What is it?
This is a "Hi-Fi" Class D amplifier for Gameboy Color internal speaker.
How it started
I've got GBC and found rusted speaker with crackling noisy sound and it was barely hearable. Headphones is not the way out.
So I searched my parts bin for some tiny amp ic and found TI's Class D mono amp. Exactly what I need. I quickly designed and made small pcb to test it out with some random phone loud speaker. Sound was great and loud. You can read the full story at avrnoob.com
New in version 2
For the next version I selected other Class D amp from Analog Devices, it's even smaller. I pick smaller one so I can make pcb which fits in the speaker cutout in GBC, just on top of the speaker.
Benefits by using it
Main benefit is the sound volume, it's much louder than integrated amp, and takes no space inside.
Class D amp is very power efficient, this means longer battery life, significantly longer.
If you add additional capacitor on the power line you can get cleaner sound than stock. This will be described later.
How to mod your GBC
You need basic soldering skills to solder 3 wires and a capacitor (not necessary).
I will provide detailed step by step tutorial.
Order Now at Tindie.com
WARNING If you connect PCB polarity wrong you will fry the amplifier IC, so be carefull.
Tools you need
1. First of all verify that you get the full kit. It should iclude:
2. Unscrew and open your Gameboy Color. Do not forget to remove batteries when you open the case.
3. Take out the speaker and desolder wires from it and from the Gameboy PCB pads shown:
4. Take 2 unmarked wires from the back of PCB and solder them to the speaker (if sound is a little distorted then swap this wires)
5. Take a wire from PCB marked "IN" and solder it to the volume control, as shown:
6. Take a wire from PCB marked as "+" and solder it to the pad shown:
7. Make sure you've soldered "+" to the correct pad, otherwire bad can happen.
8. Take a wire from PCB marked as "-" and solder to the pad shown:
9. Make sure you've soldered “-” to the correct pad.
10. Put speaker in the speaker cutout and PCB over it.
11. Set and solder black capacitor as shown. Capacitor white stripe should be exactly as on the picture:
12. Install back cover. Make sure "+" and "-" connected corrctly before turning it on. Enjoy your new sound.
If you have a little distorted but loud sound on not max volume settings then swap speaker wires.
If you have the same after swapping, then probably volume control is rusty.
If you do not have sound check all connections and wires.
If you have very low volume and heavy distorted sound then amp is probably dead. Or speaker is dead, check with another speaker.
In case you lost wire labels or want to route your own fancy wires here is a pcb pinout: