Joined: 1-January 04
From: Bay Area
Member No.: 87571
Xbox Version: v1.3
360 version: v3.0 (falcon)
If you've got power brick for a SLIM PS2 then it needs to match the voltage requirements of the GameCube.
Amperage can be as high as you want as the console will only draw as much power as it needs - unless there is a problem. Too much voltage can damage something just as well as too little, though too little usually just means it won't power up.
The slim uses 8.5v and the Cube seems to use 7.5v, don't do it.