Anybody use a 5687 tube inplace of a 6sn7?

5687 is a 9 pin I stand to be corrected I was referring to a 5692.
and 10,000 hours for Any tube is not common or likely .

a 6sn7 has a different Sonic characteristic ,for sure worth checking out 

especially matched NOS tubes.

Yes I have in facti had bought a pair within 300. Hours one tube blew and itwas a sylvania but construction looks like a RCA 4 post military tube 

don’t believe theBS they or others are 10,000 hour tubes absolutely not the norm 

at most $200 a pair I have been into tube gear since the 1970s .

I had most everything out there when they were very available and low cost.