• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.


Unpredictable. :D

I never saw 6Э5П tubes in civil equipment, but I can't imagine 6П14П or 6Н1П to serve 500 hours only like specified in their datasheets. If a TV set was up 16 hours a day it would be 500/16 = 1 month of life for all tubes. Can you imagine that? When I managed railway division in USSR we could not complain if tubes were working less than 500 hours (well, 5,000 hours for 6П3С-Е that were driving long lines). Actually, we never could complain because they lived much longer. But in case of equipment failure during some accident guilty (as the result of investigations when all involved tried to find each others mistakes) could easily go to jail. I don't remember when manufactures of tubes were called guilty.
6e5p vs 6e5p-i

I accidentally bought 12 6e5p-i on ebay. Does anyone know if they are as well liked for use in audio as the standard 6e5p?

Also, I've noticed from ebay that the 6e5p is made in at least three factories Reflektor, Saratov and Voshod. Is there a generally acknowledged favorite among these?

Thanks - M