You jacked it up. Re-do it.

Regarding the prosound mod again. I installed an RCA mod as well, and played with it for a while, until today. The gameboy now turns off by itself when there is sound. If I open up LSDJ and play a song, the gameboy will shutdown after like 5-10sec. But if I just leave it on without any sound playing, it never shuts down. What would cause that? A ground not wired properly? Or simply two wires touching each others when they arent supposed too? I'm asking because some of my wires seem too be a bit too close to each other, but I'm not sure what wire I'm supposed to  try to fix...

So basically I'm asking ,if the gameboy turns of by itself after a few second, would that absolutely be related to a ground issue  or something else?

The sound is lower using pro sound. Its all normal.

Yup pro sound puts out sound at a different impedance which causes a lower volume

I have a headphone amplifier for sale!

If I'm not mistaken a pro-sound will sound quieter with headphones but have better leveling when plugged into a mixer.

edit: oops, I'm so late, haha

Oh that's exactly it! I simply tried it quickly with my headphones to see if it worked. Didn't think about that but it makes so much sense now.

Thank you!

dont use it with headphones, or if your going to, use headphones with a preamp

with the prosound, you bypass filtering and amplification

So I finally decided to start modding a DMG. I installed a prosound mod and the sound is much better, no noise, but it's really not as loud as the original one. I checked again the tutorials I followed and I seem to have done everything ok. I don't know much about this stuff but I thought it might be caused by bad soldering (since I'm not so good at that). Both left and right channels are working fine though so I guess all wires are connected, but the sound is so quiet.

It's a prosound mod from nonfinite electronics, installed with the wires they provided. So would that be caused by bad soldering? Bad wires? A problem with the prosound itself?