I am thinking of upgrading the mk1 to mk4 . Getting touch with Bartolini is next to impossible.I wanted to ask them tech questions like 1. do I need to change my preamp that I have with the mk1's?2. How about pots ? use the ones in the bass that run the mk1 ?So does anyone know the answer to this question cuz Bartolini are out right now. (like all week)