So, I swapped a MIM J 60 Reissue with a Yamaha BBN5A. It has "vol/panpot" then "bass/treble (cut or boost)" and a mid (??) three position rotary switch. Few points: 1) what does the mid control three positions knob specifically do? 2) what does the "tone" cavity trim set? (The other trimmer being probably for the output level?). It says "Eq 2 cut/boost" but it is still not so clear to me. Is it just related to the treble? (Eq2)? Tks.