I assumed 3.5mm since there is no usb on a soundcard. And soundcards don't have a dedicated headset connection, its just the green plug I believe.yeah i think you can cuz the sound card should have a REAR/FRONT/SUBWOOFER/MIC/HEADSET out i think
what connection is the headset (USB or 3.5mm
Well kind of, I have a USB headset, when I plug it in, that becomes the primary sound device, so in a sense it disables the sound card so only the headset works, when you unplug it, then the speakers work again.oh yeah
and the sound card dont have to have USB but if the headset is USB then just plug that in and youll get speakers and headset