Korg Poly800/EX800 Users

Hi there, 

I hope someone here knows how to fix my problem!

I recently understood why my poly800 sounds bad...

Thanks to a friend who compared one of his poly800's bank with my mine 
and his own one.He told me it sounds not like his.   

Because the trim pots inside called VR1 VR2 VR3 ect.. are not "tuned".

On this group, I found the details for each trim pots.
 
But I don't know how to "tune" them....

If anybody here does know a way to set or "tune" those trim pots????
 
Please anybody who can help me answer me ASP!!!


THx in advance guys!!!