Anyone have a US or AU (preferred) power pack for a Gamecube?

Happened to buy a Japanese GC with a Gameboy Player and disc. However since Japanese PSUs are not compatible with our voltage, I bought a 3P one. Unfortunately it seems the 3P Power pack causes some interference on the display (wavy lines).

It works great otherwise.

I am not 100% sure if it is the 3P power pack so if someone could also be kind enough to loan me a US/AU GC Power Pack to test, that would be appreciated. Also open to buying or borrowing a step down converter.