Ah… it was not muted and I did not try PAVCtl. I did, however, discover the problem.
I’ve had Dino installed for almost a year, but had not messed with for a long time. I also had setup my XMPP account in Calls and Chats, but had also grown bored with them… it was all just so clunky.
I started messing with Dino again in the last few days – it seems to have gotten somewhat better – and gradually noticed that Chats was crashier than usual. It got so bad today (with Dino running all day) that my grey matter finally made the connection. I disabled my XMPP account in Chats and sound immediately started working!
So, not a hardware problem… a software conflict!