Mine just arrived yesterday afternoon and after goofing around with it for a bit at the office, I finally got it home in the evening only to discover a glaring audio problem. When I hook up speakers to the headphone jack in the back, anytime audio plays there's a very distinct and hissing sound that sounds like white noise. For example, if I just hit the volume up or volume down button to make that beep sound whenever you adjust the volume the hiss comes on for about 15 seconds and goes away. If I play music, it's there the entire time until the song ends and it shuts off about 15 seconds after the song ends. There's no issue if I use the internal speakers and I don't notice a hiss when using regular earphones or a pair of headphones. If I plug in the speakers though the hiss comes through when audio is playing. There's definitely nothing wrong with the speakers because they function perfectly on a Mac Pro Octo sitting right next to it. I also tried wiping the OS and doing everything from scratch and it's the same issue.