The secret to tube life ... which I learned 45 plus years ago with my dad in his TV repair shop ... allow enough time for the tubes to warm up. I allow for at least a half hour. Even though the Prima Lunas have circuitry to allow for play after 30 seconds, I find that the tubes last longer and are pretty noise free, when I just let them warm up. I am getting good hours on the EH ... can't say whether it's a 1000 hours or more, but I have not had to replace them in at least a year or so. The EH cost is also very reasonable ... about $20 a tube, so it's not that big a deal.
Rich