I currently own a MacBook Pro 13.3" (mid 2010) but, as abundantly reported, it emits a hissing noise out the headphone jack while the sound circuitry (DAC and / or amp) is on. On top of that, it makes an annoying, distinct clicking noise when switching on or off. From countless forum threads I have read, this problem is caused by the sound circuitry not being properly grounded / isolated from the rest of the components, letting high frequency through the audio output jack. That's so annoying that I'm selling my MBP bought last week (used). I am considering one of these new MBP as I'm hopeful Apple will have fixed this issue, at last. I know they're able to produce clean silence since the audio of an early 2006 iMac Intel of mine was perfect. So my question to the lucky owners of these new early 2011 MBP is: do you get true silence via the headphone jack? I mean absolutely no hiss, crack, pop, buzz, click, and no difference whether the sound circuitry is on or off -- especially listening through decent, low-impedance (~50-80 ohms) headphones, like a Sennheiser HD 595 or beyerdynamic DT 770 Pro (80 ohms)? Thanks.