I can't understand why you need a 20 amp when your gear only uses about 500 watts. 1 amp= 110 watts so a 15 amp circuit is about 1700 watts; a 20 amp is about 2200 watts, it is like using a 5 amp fuse when you need a 1 amp fuse. You are better off having a breaker trip instead of frying your gear. I know of no audio gear that would ever draw that much current,but if it makes you feel better go ahead and do it!