Korg Poly800/EX800 Users

Hello,

I just bought a used poly 800 off ebay and am quite amazed by its 
sound. The only thing that puzzles me is this strange white noise. 
Mostly it's way too intense and the procedure of putting it down is 
quite unhandy. 
So now I've seen on some website that the VR-3 is responsible for white 
noise adjustment. My question now is: Can I just unsolder this part and 
solder a pot to it instead - like you can do it with reso -  so I can 
regulate the white noise intensity? Which pot do I have to choose and 
even more intersting for future mods - how do I find out, which pot I 
have to choose.

Thanks in advance,
beloc