Well I've been pretty disappointed in the sound quality of the unibody Macbook Pro when plugging in headphones. There is a strong hiss and a lot of detail is lost. So I'm thinking of getting a Astro A140 Mixamp. My idea is to use the digital out from the macbook pro, plug it into the mixamp, and then plug my headphones into mixamp. There are a few reasons I want to get this besides sound quality alone, but improving the sound quality coming from the unibody is a top reason. How good is the sound quality from the digital out though? Is it as good as an iPod? Anyone have a similar setup?