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.
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.
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.
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