The TDX card is designed to work with power speakers. Though you can use headphones you can’t obviously adjust the volume :). I was looking around on ebay and came across a smart little headphone amplifier by FiiO that works very well with the TDX card. It is the E5 model and has volume control, and bass switch as well as a re-chargable battery (via USB) that apparantly gives you about 20 hours of use. Quite handy if you want to use headphones when the misses doesn’t want to hear the tink tink of 80’s computer music ;). It was only about £9 here in the UK and looking at the USA Ebay site think you can get it cheaper.