Its bettter to be safe than sorry.

Did you even read this thread?

I posted pictures just a few posts back.

Where do I connect the wires to the circuit board?
Where does ground go? Where does left and right go? (on the circuit board and on the jacks)

You'll have a harder time soldering though xD

Nope. you can connect 120 prosounds at post an pre pot. whatever you want. It's just advised to not use more then one at the same time.

So if i put my  prosound 1/8" on either pot or post, i have to put the RCA on the other?

Then you're probably just using 2 wires, which are the "left" and "right". The stock jack is already grounded, so there's no need to do anything else, I suppose.

I never put a ground on mine, I do internal prosound using the stock jack. Should I be grounding it?

You ask too many questions.

So your saying that it would just put it to the highest setting of the volume slider? So if i put my  prosound 1/8" on either pot or post, i have to put the RCA on the other?

Max Volume Baby! yeah!

What happens if it inst hooked up to the volume slider?

You can install as many pro-sounds as you want. I wouldn't use them all at the same time tho.
you could install RCA and jackplug in one gameboy for example.

and post and pre pot is just as it says. before or after the volume pot.

if you install post pot, you can use the volume slider to control the prosound. see the pic i posted a few posts above.

You need at least 3 hook up wires right? Whats post and pre pot? Does it matter if i have a prosound mod already installed?

Im having trouble with this too, can some one make a tut? Or find one please?