All those Famiclones come with 9V 500mA adapters, but as you pointed out the batteries in the Power Player only add up to 6V (and actually I have a different one that only needs three AAA, so that would be 4.5V). I expect that if you got a lower voltage adapter, you'd want a higher amperage rating. So at say 5V, you'd probably want 1000mA.

Tip needs to be negative and it should output DC.


...word is bondage...