Woody I'm almost positive that's only a concern if you're wiring more than one speaker up. You don't want to get them out of phase with each other, if they are out of phase then they will cancel each other out. All of the output circuits that I've run into are drivin by an audio transformer, and a transformer will only work on AC or alternating DC and as you know an AC plug can be turned in either direction. Just reverse the wires and give it a try.
Maybe Fred N. will step in and offer us a more technical explanation; he is much more of an audio man than I am.
All that said, I thought I was wrong once, but as it turned out I was mistaken!
Last edited by Denny Graham; Wed Oct 27 2010 12:24 PM.