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.
