Received the little Koss the other day and plugged them in to my Nuforce HDP immediately. First thing I noticed was how much more efficient they are than my Beyerdynamic DT990 premiums. Had to turn them down a bunch. I run my ipod on shuffle and the first song was Oh Darling from Abbey Road. McCartney's bass was amazing on these little guys; not overpowering, but clean, punchy and super easy to follow. Very promising right out of the box.
I didn't have time to listen so I turned the volume up just a bit, took them off my head, and let it shuffle away all day to burn in a bit. It's too early to address the sound from the KPH30i just yet, but I can address a couple other things. First is comfort, and yes they seem like they will be very comfortable for extended periods. Back in the day I owned both the Sennheiser HD410 and the HD420. Both of those would rub my outer ear and had to come off after 45 minutes or so. I don't think that will be the case with the Koss.
The other issue mentioned by Alex is the 1/4 inch adapter. My HDP has a 1/4 inch jack and maybe I was lucky, because when I reached in the drawer and grabbed the first adapter I saw, it worked fine. Haven't tried it with my phone, and probably never will.
