This is essentially a direct replacement for the OEM Sega Game Gear sound board. It's perhaps the easiest of all the DIY options out there to build. The resulting board can only output mono sound to the speaker, just like the OEM board, so if you are looking to upgrade your Game Gear to stereo, you may want to check out the SYF board.

The parts listed here in the displayed BOM include polymer caps instead of electrolytics. You could use electrolytics instead if you so desire, but I recommend polymer caps anyway. You can get everything from most component suppliers, however, I have found the volume wheels are chronically out of stock almost everywhere besides AliExpress of all places. Be careful when you select your audio jack. The standard PJ-307 won't work. You need the "longer" version with an additional 3 pins in the back. Be careful you don't also get the version with 6 extra pins. For the TDA2822D, try and get the genuine ST chip as the other brands are hit or miss. Also, be careful to not accidentally buy TDA2822M chips, as some sellers on AliExpress will list chips as "TDA2822D" but then have pictured TDA2822M chips. TDA2822M chips will not work. I've tried... if you plan on using this board with VA4 or VA5 boards, you will need a different male 6-pin connector. You could technically just use a 2mm pitch male header, but you'd have to be extra careful not to install your cable backwards if you do. I'm not sure what connector the VA4/VA5's use, but it might just be regular old JST-PH or MOLEX.

If you're like me, you order parts for projects, forget about them for a few weeks or months, and then spend 20 minutes looking the BOM up again. The BOM is printed on the back of this board.

Oh, I recommend you order the PCB in 1.2mm Thickness.