Shugaung BT 181V

 I have had a pair of the Sophia's and one blew.  That is typical for Sophia Tubes, in my experience they just aren't reliable. They do sound good but don't stand the test of time. Not to mention they are just rebranded TJ Tubes that you're  paying a premium for. For the same money you can  get good vintage options from reputable seller's that will sound just as good or better and will last. 

If you want another very good new production option you might consider Sophia Electric 6SN7s. 

Interesting. I was going to get them but there is another thread on these indicating some issues the tubes develop after a period. If you have a need for 12AX7, they have a BT version which is excellent at Grant Fidelity.