There is no difference between Linlai and Linlai Global. They are the same. Linlai Global is what you get when you buy direct from China. For whatever reason they decided to use a different brand for the export market.
Our Linlais do indeed have the serial number stamp on a plate inside of the tube.
The E-6SN7 is an incredible tube and we hope that they conitnue to expand their line.
Every single tube that we sell is genuine and we go through great lengths to ensure this. Though, I haven't ever seen a fake new production tube. Ever. There are fake vintage tubes floating around which is where the myth came from.
It's particularly silly when talking about the E-6SN7. I am unaware of a globe style 6SN7 ever existing previously, and such a tube was never even made back in the day. There isn't a tube to even fake.
There are only a few factories in the world that produce tubes. Do you really think the manufacturers would silk-screen a competitor's brand onto their own product?
If someone does have an example of a fake new production tube I would love to hear about it.