I've narrowed my choices down to: - Sennheiser HD25-1 - Denon D2000 - Beyerdynamic DT770 ('05, 250ohm) The questions I have are: - Do the Senns hold up to either the Beyers or Denons, sound quality wise? I've heard their isolation is fantastic, and that's a plus in my opinion, but I...

I'm currently looking to upgrade my amplifier and these two amps, the PIMETA and the PPA, have piqued my interest. I'm current running two pairs of Beyers, the DT770 Pro-250 at work and the DT880 at home, through a pair of Cmoys that I've built. I've heard all sorts of things about how great...