no it wont fry your motherboard lol trust me im a electronics engineer the worst that could happen isat full volume the amp would struggleif you have a spare pc psu you could use that its only a matter of linking 2 pins together to runit as a seperate power source but if your not comfortable with that dip into your pocket and order a 12volt psu 7 ampshould be plenty
no thats not true its all about using the right impedence