Bah!

I just wasted a few hours trying to get audio from my laptop.  Somehow the speakers no longer work, but the outputs to other devices are fine.   I then made the mistake of tweaking a setting a little deeper on the software mixer and suddenly it was all gone and nothing brought it back...until I got in the time machine and returned to Monday, before I messed with it, and now I'm back to square one and am resolved to accept it.