LOL!
Actually, *all* GE labeled tubes aren't bad. Only the ones made by them. There were lots made by other manufacturers and OEM'd for GE, and those might be quite good. I have some GE labeled 7N7's that were made by Sylvania and they're awesome.
So how to know if GE made a particular tube? Only way I know for sure is to plug it in and listen. If it sucks, GE made it.
Damn, GE labeled