Wouldn't it skip a lot of steps to just boot straight into a secondary drive with a clean install of OSX
I suggested the other way around for two reasons:
1. If you do it the way I suggested, and it "fixes" the issue, it tells us two things at once:
* There is nothing wrong with your disk hardware.
* There is something "wrong" (or conflicting) on your existing installation, software wise.
If you do it the other way, it can only tell us the second thing, and not rule in or out the first (and if it still fails, you'd still have to rule out disk trouble).
2. You're not really saving time that way, because if it works, you're going to want to migrate anyway. My way, you're already there. The other way, you have to (unless you have a third disk) do what I suggested anyway, so you can start fresh (because you're going to need somewhere to "stash" your existing install while you build the new one).
How about this: What if another player on my hardware can play the exact same files from my media library for some period of time (say 2 hours) without a dropout? That is probably going to be my next test unless someone says the logic is flawed there for some reason.
I guess I'd assumed you'd already done this, but that doesn't really tell us much, because MC uses the hardware very differently than most other players.
I'd like to emphasize, that I'm not convinced this will help. Like I said above, where there's smoke, there's usually fire. But, we're stumped right now. Plus, this gave me a
lot of pause:
and was reminded that the previous owner of this machine used to have a Digi Designs sound interface (DAC, soundcard, whatever) and it still appears in Audio MIDI Setup.
The machine had a previous owner and you're still using their installation?!?
That is... Well, you have
no control over (or knowledge of) what chaos might have happened on the machine before it got into your hands. Maybe it went through three "bad" upgrades? For example, how long has that partition been around? OSX has trouble with in-place upgrades sometimes. It is known. Or, what if they'd installed (and partially removed) wacky, troublesome system services or mods in the past?
If I ever buy used hardware, step one is a nuke and pave. Period. No exceptions. Even if the owner is my buddy from IT and I know they probably have something okay. Still not worth it. Start fresh.
So, those two things combined made me suggest it the way I did.