That was cool. I like the first tube Haltron (Tungsram), the Tesla, The RCA (which is really a Sylvania) and the Chinese C8 (had the etched glass) and finally the tube labeled ATC... I can’t see enough of the plates to tell what it is. Kinda reminds me of a Brimar CV4004 box plate. You can also hear how less dynamic and darker the new manufacturer tubes are.
Seems the person who made the video doesn’t know what tubes they have... I highly doubt they are using a 6n2p... unless they are rewiring the tube socket. Either way, it way cool to listen to.