I'm going to order an Aguilar OBP-3 and stick it in my Warwick Corvette 6. I was looking at the wiring diagrams on the Aguilar website and it looks like i would be using the blend, volume,stacked tone wiring. The thing is that in the wiring diagram it looks like i would have to drill a hole into my bass to stick in the pot for the mid. Is this correct? Also does the OBP-3 come with pots?