Running it on 9v i would say is not adviseable - do the 12v thing as soon as you can.
just for those who arent sure of this amps stuff...
- You CAN use a higher amp rated supply than the 0.57A, such as a 2, 3 or 5 amp etc, as long as its 12 volts dc.
- You shouldnt try a lower rated supply, or...