Ok, I know there are no stupid questions, only stupid people, but here goes... I rebuilt both a HP-23 and a HP-13 power supply for my Heathkit HW-101 The HP-23 has 12vAC output for the filament while the HP-13 doesn't. I assume I'm just to use the 12vdc that powers the HP-13 also for the filament voltage. I looked at the schematic but I'm missing where that 12vAC is rectified to DC. How does it work with either 12vdc or 12vAC?