EAT KT-88 tubes


I purchased eight EAT KT-88 tubes for my CJ amplifier. They sound fantastic, but two tubes went bad in 300 hours of use. Has any one else had issues with these tubes?
exelchuck
Hope they are still under the 6 month warranty! Normal power tubes are supposed to last for about 2,000 hours, so how come these super duper tubes failed at 300 hours? There are a lot of KT88 tubes that have excellent sound for a lot less money. BTW, I have a CJ power amp also, but it uses 6550 tubes. I wanted to roll the 6550's to KT88's and so I spoke to Ed at CJ. He told me it would not be a good idea to replace the 6550's with the KT 88's, because in all likelihood, I would be unable to bias the amp. Hope you didn't do what I was going to do because that could be the reason for the quick tube burnout.
Of course it was after 6 months. EAT/Music Hall replaced the first tube, but I haven't received a response on the second.
For the statistics: in 8 months (please don't ask me how many hours that is, though) no problem of any nature with the two I've been using. Keep my fingers crossed.
how much does a pair of these kt-88 tubes cost? where did you buy it? heard from review they can make your 2k amp sing like 20k amp.