The headset is stereo, so I'm wondering if a sound card will make any or no difference. Also if you think it's worth getting one, which one would that be? Also I'm using a MSI Z97 Gaming 5 motherboard.
Some people complain about the onboard sound card (ones built into the mobo) because they pickup internal noise that you can hear through your head phones. If this is the case then the problem can be fixed by getting a Sound Card.
Sound Blaster still makes good sound cards if you are looking for one.