Thanks guys. My dad mostly listens to Jazz, Country and Old rock music. The media is CDs mostly, but he has a large selection of Mp3s on his comp with an Audigy 4 sound card.
The amp will be made by him. I was thinking of getting him a cheap Tube amp like the Little Dot tube, but have no money left ! I thought maybe my dad would listen to them without an amp, but he has packed the headphones away till he can get an amp for it.
He actually doesn't have a decent set up (besides the amp) - (just a Pioneer DVD player + his own amp) to get the full potential of the headphones, but he will have to upgrade to a better player with better wiring now that the headphones are there.