Well, Halted had a tube tester in the corner until the day they closed a couple years ago. There are NOS audio tubes still available. But if the random stuff sh

Well, Halted had a tube tester in the corner until the day they closed a couple years ago. There are NOS audio tubes still available. But if the random stuff showing up in my Youtube feed is any indication, the cool kids these days are learning glass blowing and making vacuum tubes from scratch.