The smaller socket 2.5mm is for powering the noise cancelling headphones 5v dc I think (could be wrong about the voltage, virgin is 5v) the other jack is a standard 3.5mm stereo jack and is compatible with nearly all headphones.
Sorry for the double post, no idea how, I blame the iPad
Last edited by joejet; Apr 3, 2012 at 5:26 am
Reason: Oops double post sorry