I believe the Old Head PID is the Auber style pinout. So it is not compatible with Qaroma coils. You can, of course, buy just the Qaroma XL head and use a compatible coil for your PID.Is there some pinouts charts for the PID, since it seems its different depending on the seller. I'm already thinking about buying a Quaroma XL, so i'd like to reuse the PID Controller.