Installation wasn't the easiest. But I got it done at about half an hour. At first I thought it didn't work until I realized I was using a reproduction cartridge that had major hum on it. Once I used a uthentic GBA cartridge, I noticed that there was zero hum and zero hiss.

i use unleaded solder (99.3% tin/0.7% copper @ 350c) and the solder just wanted to whet up on the pads and not bridge between the ribbon and GBA. flux didnt help with that. wound up needing to use a wire to bridge most of the solder pads.
ive tested but even on volume off ive got a hum. i also have a amp and a CUI speaker installed. it might just be my GBA revision. but honestly ive not seen any kind of benefit from this,

Just what I needed

I love this mod! It’s easy to install if you have a bit of attention to detail and it provides a clarity of sound for headphone users that is a must!

Added this alongside the CleanAmp and I can say that the audio quality leaves nothing to be desired. Sometimes I have to double check that the volume isn't all the way down when playing a game and there's silence for more than a few moments.

The install was very straightforward with no issues. After install the GBA would not work correctly. I experienced game glitches and screeching from the speaker. Uninstalled and everything was back to normal. I might have gotten a bad unit though but I am unwilling to try another.