I plugged in my super gameboy for some castlevania fun and I noticed that the sound quality was pretty horrible sounding. I cracked open the super gameboy, looked up on the internet the pinout of the snes cartridge connector, and found the pins of the cartridge that the super gameboy is using to mix in its audio. I traced the audio paths from the chip to the pins and really the only thing that's in between is a low pass filter.....which I have no idea why it's there in the first place.
Anyway here're the capacitors that make it filter the sound so it becomes more muffled:
http://imgboot.com/images/Drakon/sgbaudiofix.jpg
Here's what it looks like after I removed the stupid filtering caps:
http://imgboot.com/images/Drakon/sgbaudiofix2.jpg
And here's the sound quality difference:
http://www.youtube.com/watch?feature=pl … 0aAoBJA39s
The caps are labelled as 104 so they should be 0.1 uf if you ever feel like replacing them. I think the system sounds wayyyy better without the caps.