skeptic
Headphoneus Supremus
FWIW - as far as battery powered portables go, I'm not sure anything out there has significantly more "juice" than an O2. Double 9 volts certainly aren't going to drive a HE6 and there's some controversy over whether or not an O2 can really manage LCD 2's, but even at unity gain, a stock O2 can easily drive AD's or any other fostex t50rp based headphone. I used my stock diy O2 quite often, for several months, with my AD's before the mod and found the pairing to be quite good, albeit a little light on bass for my tastes. Playing with the doggie treats and adding the agdr mod have left me very happy with my bedside rig though.