Old thread, I know, but for curiosity's sake, which pins in the 9 pin socket are the positive and negative pins between pins 9 and 5?
I'm about to wire my amp up for a 6v light and I'd like to color coordinate the wire to the appropriate pin; red to positive and black to negative. I know I don't need to do this for an incandescent bulb, but some day I might like to wire a 6v LED in there.