I took the initial stab at designing the pickups, then Joe Barden came in and did his own design, initially very early models had taps for dual impedance but that was soon changed to a single impedance twin coil (side-by-side) humbucking pickup. Phil (greatest boss ever!) was not know for his electrical prowess and gladly differed the electronics task to me, who then differed to others (Link Removed did the electronics, or enough of it to hand off to me to finish). Even though Seymour Duncan was local and a frequent visitor (and his shop was a few feet down the street for awhile) Phil, Carla & Geoff were adamant the bass have it's own pickups & electronics.