Sad day for me today, I flipped on the switch of my Transporter and my EML decided not to glow. I swapped it out for my HW CV-378, and that one fired right up. My guess is that my EML had about 600 hours on it. IMO that is a painfully short lifespan for an expensive tube like the EML. There is no denying that it does it's job exceptionally well, but I am a little reluctant to buy another one if it won't even last me a year...
After emailing with George at TubesUSA, it would seem that the lifespan can vary greatly from a couple of months to a couple of years, depending on the individual tube and it's application. He also mentioned that if the tube was showing some grey carbonization on the inner envelope of glass, it may be getting too much voltage, which would in turn lead to a shorter life. Mine runs behind a voltage regulating power conditioner that restricts voltage to 120 (+/- 3v), and showed no such carbonization.
So, now that many of us have had the EML for a while, and some are on to their second tube, would you guys mind sharing the approximate hours that your EMLs are lasting. If 600 hours seems to be common number for use in the Transporter, I'm not sure that I will go for a second one.
I have no regrets about the first one... just wish that it had lasted a little longer.
Cheers