Linlai E 6sn7 tubes

Last night I was listening to music, and decided to do a little experiment.  I shut everything down,and waited a few minutes.  I then preceded to put the Linlai’s back in the system to verify the bad tube and mark it.( since I had failed to do so the other evening.)   After putting them back in,they have worked flawlessly.  I am thinking in my haste,I didn’t seat the tubes correctly?? They have about two hours on them since trying them out again. Not a peep out of them, but great music.  Anyone care to speculate what the heck is going on over here?  At this point,all is not lost,as I have a back up pair on the way.

@rocray a bit after I first got my 6sn7/cv181-TII psvanes, something similar happened. 1st time I tried them, fine out of the box. Later had removed them with barely 10-12 hrs on them. A few weeks later I re-installed them, at startup for about 45-60 seconds I heard this fuzzy sound, grainy, mildly static, as if some of the internal coating had flashed off or something, maybe barely arching with small particles floating around. Went away after 3-4 minutes of warmup at startup. Same thing happened with some small signal/driver vintage true NOS tubes from Brent Jesse. Intermittent static, a few pops. He had me pull them, tap them on the counter bottom/pins side down, 3 taps, and put them back in - and cured, gone. He shared maybe some micro burned off particles floating around with these new/un-played tubes would settle at the bottom of the tubes, fwiw. No issues since on the new output tubes or the older nos input tubes since. No clue if anything like this is related to yours, sharing a similar type experience. Pull, lightly tap-tap-tap, re-install. Happy listening. 👍

@xcool We should be. Thank you for brining this to my attention.

Hi @vivatubes, that's great.  That would definitely help erasing some doubts and speculations for many of us here.   Thanks!

Does it come down to silkscreening and nothing else?  Or??