Thanks guys for the feedback. I tried using my iPod as an input rather than my laptop/USB, and I find the sound to be less harsh.. did I bypass the PanAm DAC by using the iPod?
also, I'm currently using a cheap USB cable to connect my laptop to the PanAm, do you think that using higher end cables makes any difference? I thought that a USB cable is digital so it shouldn't really matter much.. eh, I don't know.
p.s. I've also tried Westone 4 with the PanAm and I prefer this pairing more than the DT880, I guess my ears are just partial to the warmer sound.. although I really bought this to drive DT880. it's growing on me though, I like it much better than my first listen.