Thanks for the response MarkW, I couldn't find the owners manual on line. I had thought that would be the case, but wanted to be sure before I tried it.
As it turns out I have bigger problems, with only the subwoofer plugged in to the outlet the LED lit up, and then slowly died, as did the fuse. Because the fuse didn't blow immediately I'm hoping that the problem is in the power supply, that I can deal with.