Gameboy Player audio improvement mod

My buddy ace mentioned that the gb player for the gamecube muffles gameboy audio to death.  I tapped the audio traces of the gb player cpu and wired up a low pass filter that ace suggested and it sounds fantastic.  I wired up a toggle switch that toggles between system audio and my bypassed gba audio.  Here's the demo video showing the difference in audio quality between original and improved:

I had some free time this morning so I took a picture of my gameboy player audio setup:

I tapped system audio from the av port pins and connected them to a header.  The toggle switch switches the rca jacks between gba bypassed audio and main system audio which is how I was able to make this video with real time switching.  These headers are temporary.  Down the road I'll probably attach a better looking connector unless an even better fix comes around.

Copied from my post on gc-forever:

My buddy ace mentioned the gb player has really muffled audio on the gamecube. I finally noticed the muffle myself so I cracked open the gb player. Thanks to the wonderful nocash documents he mentions the gba cpu pinout which says that the audio lines are pins 6 and 7:

http://nocash.emubase.de/gbatek.htm

The gb player pcb has these convenient "test points" where you can solder wires to the traces and tap the lines:



Sound was clear but had a whining noise. Ace told me a lpf that worked for him so I tried it. Both audio lines have a series 470 ohm resistor followed by a 0.01 uf cap to ground. I built the filter and the sound came out perfect. I wired a toggle switch to go between original system audio and my bypassed audio:



Here's a video where I'm playing music and switching between the audio sources so you can hear the difference:

Drakon wrote:

Copied from my post on gc-forever:

My buddy ace mentioned the gb player has really muffled audio on the gamecube. I finally noticed the muffle myself so I cracked open the gb player. Thanks to the wonderful nocash documents he mentions the gba cpu pinout which says that the audio lines are pins 6 and 7:

http://nocash.emubase.de/gbatek.htm

The gb player pcb has these convenient "test points" where you can solder wires to the traces and tap the lines:



Sound was clear but had a whining noise. Ace told me a lpf that worked for him so I tried it. Both audio lines have a series 470 ohm resistor followed by a 0.01 uf cap to ground. I built the filter and the sound came out perfect. I wired a toggle switch to go between original system audio and my bypassed audio:



Here's a video where I'm playing music and switching between the audio sources so you can hear the difference:

funny - i just noticed the terrible audio on the gbp the other day when playing harmony of dissonance.

I had started wondering about low pass filters, etc inside the gbp.


so what did you do did you add that wire between the two units to mix the gbp audio into the multi-out?

thanks drakon.

The wire in between is the system audio out. The toggle switch toggles between system audio and improved gb player audio. The thing with improved gb player audio is it's gba audio only so if I'm in the mood for some gamecube games I need to switch back to system audio which is why I installed that setup.

Drakon wrote:

The wire in between is the system audio out. The toggle switch toggles between system audio and improved gb player audio. The thing with improved gb player audio is it's gba audio only so if I'm in the mood for some gamecube games I need to switch back to system audio which is why I installed that setup.

Ah so i dont even need that extra wire since the reason i own a gc is to play gameboy games.

Right if you're exclusively playing gba / gb / gbc games you won't need the extra wire and toggle switch. I just put that in if anyone wants to play smash bros or something else.