how do i get a master account on my ps3

how do i get a master account on my ps3? my brother bought a ps3 a while ago and i was under age. now im 18 and he took his ps3 back, so i got my own. after setting everything up, i go to psn and do the "use exsisting account" thing to use my ID and stuff. it didnt ask me weather or not i wanted the master account. is there a way to make my account the master one on my new ps3? Video & Online Games - 1 Answers Random Answers, Critics, Comments, Opinions : 1 if you are over 18 it will automatically make you the master account if there s no one else older than you with an account on your PS3