I have a 1988 spector bass. I bought a set of EMG PJX pickups for it and An Aguilar OBP-2tk Preamp. I took it to my local tech and he says he cannot wire the Aguilar to my EMG pickups. I thought spector's can come from the factory with EMG active pickups and a Aguilar (Optional)? Why can't my tech fix this? Is he not a very skilled tech? HELP!