Hi I have two forthcoming flights on a QF Boeing 787 in premium economy class: MEL-LAX-MEL. It is my first time in this class. Do the complementary headphones only fit the in-seat input socket which I suspect is 2 pin or do they also fit a single pin device such a tablet/phone? I have my own quality headphones but would rather not carry them if the Qantas product would fit my own device as I would only use them on the flights.