Voodoo Lab

The manual says that the GCX cuts down on ground loops by lifting the return ground. Wouldn't this action be negated since the audio signal is connected to Out which is most likely connected to the rest of the Audio common? i'm confused.

The lifted ground on the return is to prevent ground loops. A ground loop occurs when there are multiple paths for ground to follow. As you noted, the audio ground is still connected through the signal path. The only scenario that this will affect is when switching between two signal sources that do not share a common ground, like two instruments. This is solved quite simply by connecting the cable sleeve to any other cable sleeve in that particular loop.