I got a Grado Sr80i Headphone past month. So, my main audio source is a Late 2007 macbook (yes, a pretty old mb... I plan to buy a macbook pro). I can't found anywhere a good info about the output sound quality, but I think and hear thats not really good. The question: Do I need a Fiio E7 DAC to improve the macbook sound output or a Fiio E6 amp gives me a good solution? I'm considering the difference between both values.