don't know if i'm blind or not, but i can't find an existing guide/topic for this one.
So here's my n00b problem:
I bought this USB sound card: https://www.amazon.de/gp/product/B008KG ... UTF8&psc=1
its similar to the card thats mentioned in the wiki under 'working'.
i already soldered the GameBoy's headphone jack to the speaker,
but what exactly do i do now with the sound card? where should i connect it with the headphone jack?
the amplifier in wermy's guide is something completely different...

thats the sound card opened:

I'm thankful for every response!