Okay...update on my problem...

Last night, the crackling came back in-game from the sound (using digital out) until I restarted, though even after restart I still had a little bit of crackle (not nearly as much, though, where things would turn to static practically).

Popping/clicking in Teamspeak is still going on. It's an intermittent thing rather than happening every second or something like that.

I ran checks on the memory et al. and that all seems to check out OK.

I have until tomorrow to exchange it for a new one, but I'm kind of reluctant to tear everything apart if it isn't going to help with this problem. Any more ideas, guys?