PS Audio and Cardas both make PC with the 2 prong C-7 connector... Check AA or Music direct.
power cord upgrade
I recently bought vintage accuphase preamp. It has detachable power cord but it is not 3 prong but only has 2 prongs. I have only seen 3 prong power cables. Does anyone know of an adapter so I can use my 3 prong power cables.