I just got a new pair of Beyerdynamic Tesla T1s and have been listening to my newly completed crack. All I can say is that my mouth is still hanging open. I have listened with a pair of DT880s 600 ohm but the Tesla T1 just left me speechless. The Crack sounds better than I could have ever imagined. A full rich sound with plenty of low end and great clarity. The Teslas added a nice attack or speed response. They are also more sensitive, and the music very detailed. I like the rear tilted drivers. All in all, I couldn't be happier. I have this amp in my office to help drown out some of the background noise, but now I can only concentrate on the music and my work is not getting done. Thank you bottle head.