I use the 303/300 in my system and have tried a lot of different power cords with it before deciding on the best ( IMO) cord for it - the Nirvana Source AC power cord, which is not insanely priced ($595/1.5M), but gets the very best from the 303/300. Second place went to the Purist Aqueous Anniversary power cord, but the Nirvana beat this out at least in my system. Have FUN!