I acquired this wm1 with a amplifer I recently purchased. The seller didnt have the power supply for it. I've read the manual and know that it uses reversed polarity. The issue is finding the correct size Walwart. I will probably just cut the cable and wire it in reverse , solder it and heat shrink it etc. Anyone have a idea on the size I need? I've always wanted one and to find out it was with the amp i bought i was very happy.