I have an early 90's Ibanez SR500 that I want to change PUPs on. Was thinking about using EMG P/J setup. Is this an easy switch out of pickups? or do I need to replace preamp as well? If I dont wire the old preamp to the EMGS are they ok by themselves? Has anyone done this and were you happy with the result. Was also just thinking about buying a new Ibanez bass instead of spending money on the old one. Thanks,'