I am using an old Bluetooth speaker for my audio amplifier for My GCP, but I ran into an issue. The amplifier's speaker doesn't have a common ground, so it won't work when I connect it to the gamecube. If I power the amplifier externally, then the sound works fine, but if the amp is powered from the GC, I get power but no sound. Is there a way to remedy this? The ground I'm using is the pin next to 5v and the video out pin.