Expected hours for JJ Tesla KT88?

Folks -
In March 2007, upgraded stock Sovtek 6550 power tubes to JJ Tesla KT88s. The Sovteks had lasted 5 yrs or so (and still have some life left). A KT88 (JoLida 502B v8 position) failed in Sept after about 400 hours. A second (v7 position) began glowing intensely red today after about 700 hours. I powered down before anything bad happened. I'd heard KT88s were less robust than the 6550s. I do take care with proper biasing. Curious what the experience of others has been with KT88s and JJ Teslas in particular. Thanks in advance for any feedback.
I have no experience with the KT88's but, I've used JJ EL34's and had the same problem as you. I switched to SED winged "C" EL 34 tubes and have had no problems at all. From what I've read, JJ tends to have a lot of quality problems. They sound good but, I'd stay away from them and change them all immediately before they damage your amp.
Hanki - Thanks for the input. The JoLida seems pretty robust. I'm inclined to run the JJ/Teslas for the time being(I have spares). As funds permit will consider buying a set of SED Winged 'C' KT88s. SED Winged C was on my short list originally. One of the guys at the Tube Store had recommended the JJ/Tesla KT88s and I was very happy with the sonics (compared to the stock/5 yr old Sovtek 6550s). But <<1000 hrs just doesn't seem right. Who are you buying your tubes from? I'd been using the Tube Store (Canada) but recently ordered from Doug's Tubes and was happy with his prices and promptness. What about you? Best wishes for a Happy New Year.
I have used the Tube Store with zero problems with my 5 quad sets of Chinese KT-88s. The eastern Europe 88s have a rep for poor quality control which equals the low cost. JJ tubes really do sound good but you should expect a tube to go every so often, not the set but one here and there. I personally like the Tube Store Chinese KT-88s which are more extended than most others and last me around 4 plus years.
One thing I have noticed is some very inefficient speakers will shorten the life span of tubes, what speakers are you using them with. Your amp is also not the most robust when considering the power supply which is also in the chain.

The Tube Store also has a blown tube program that will match the set of tubes you purchased with a new one, a very nice feature.
I guess I should be glad I'm only dealing with 1 quad and not 5! I did purchase the JJ/Tesla's from the Tube Store (on their recommendation). I've been happy with their service though pricing with the declining dollar was better in the past hence the use of Doug's Tubes more recently. I did buy matched tubes from them and when ordering spares used their perfect number system. Have to say when installing the spares it wasn't plug and play as expected...re-biasing was needed. I had thought matching meant direct replacement without the need to re-bias. Not really a problem since each power tube in the JoLida can be sepaately biased. Perhaps matching meant less of an adjustment was needed than would otherwise have been the case. I'm running Totem Forests (~87db) so not all that efficient but not the nadir of inefficiency either. The JoLida has been a good value for me - do you think power conditioning might help? Note too I had 5+ yrs on the original Sovtek 6550s so am inclined to think it might be more an issue with the JJ/Teslas. Are you running the Shuguang KT88s? They are the only Chinese KT88s I see listed by the Tube Store. Note too the JJ/Teslas aren't all that cheap...not up their with the Gold Lions but at $74 a pair not exactly cheap either. OK - thanks for the input. Let me know what KT88s you like.
Not to unnecessarily prolong this thread but I had another JJ/Tesla KT88 tube failure yesterday. Adding bitterness to the pill was the HiFi Tuning Fuse the tube took with it. Amp seems fine but I could do without these extra costs. The KT88 that failed had about 450 hrs on it. Had some spares so am up and running but though I like the JJ/Tesla sound A LOT I can't deal with this failure rate after so few hours. Am now taking Jab's advice. Talked to Doug's Tubes today, they are recommending Penta Labs Solid Plate KT88s (KT88 SC; aka Shuguang KT88s I think). $150 for a matched quad. If anyone has suggestions (especially if running a JoLida) or input on the Solid Plate Shuguang KT88s (reliability, sonic qualities), I'd definitely appreciate it. Thanks in advance.
Another source for very good tested tubes would be VAC, but they do cost. They cook their tubes so a failure is very rare.