Hi Marco; welcome to the board! This is an international community, and we have some members who are good with languages (I'm not). Interestingly, the first three respondents to your post are from the United Kingdom, Nederland, and Brazil. As they have already stated, if you can describe the problems you are having with the pots, we'll try to help. As Adriaan mentioned, if the problem is that the pots are scratchy, which can happen on an instrument that hasn't been played recently, then exercising the pots, turning them back and forth through their entire travel twenty or thirty times should help as they are sealed self-cleaning pots.