Sorry, I forgot about that. Since the SCU is a 1 channel device things can get confused, and yep audio midi setup utility helps reset it. I have found other situations where you get it all set right and everything looks right but no audio is passing. Going back to audio midi setup utility and bumping the audio gain, then restoring it seems to kick it all back to normal. I have seen the same behavior on several devices based on this Texas Instruments sound chip. Sounds like you're getting the hang of it. "Works out of the box" means somewhat different things to the average ham and the average Mac user.