I purchased the ZX2 with about 80 hours of play time on it according to the previous owner. I have probably 30 hours on this custom cable (which is recommended for a burn in of 50 hours at minimum) and approximately 110 or so hours on the ZX2. Listening now and the sound from this rig, which includes the HD6XX, is just coming together marvelously as the hours add up. So smooth, warm and gooey, but detailed, with a wide soundstage, and all the instruments sound like they're supposed to sound, nothing's off or digital sounding. Thing that probably changed most besides separation going from TRS to TRRS, is the widening of the soundstage. The whole presentation is just sooo excellent.