I have a Carvin LB75p which has been sitting here for a long time not getting any love. It belongs to my brother who has been living out of the country and I have always meant to pick it up and play it but my LB70 always get the love. Anywho, I started playing it this weekend and I'm wondering about the controls on the bass. I am pretty sure that the switch operates the passive/active mode but I'm unsure. The 3 larger knobs are a little confusing. The top one is the overall volume output and I assume the middle one operates the same as my LB70, dialing in the blend between pickups. The 3rd one has me a little puzzled though because it also has a middle point but I'm unsure what it is meant to balance. Possibly the control for the piezo P/U's? I can't find the manual on Carvins website for this bass and it's version of the electronics. Does anyone have a link to them, or have a digital copy you could send me? Thanks!