i used my w1000, and w5000 on the mkv with no problem, have to turn the volume down when i switch over from my 600 ohm headphone to the audio tehcnica headphone
i dont hear any hiss at all on my low impedance w5000 and w1000, it's dead silent. i suspect it could be your source or your cable
penchum: how do u take the volume knot off? do u just pull it out?