KT88 s Sovtek vs Valve Art

I find the JJ(Tesla/Teslovak) KT88 to be the best sounding of the currently produced KT88. I do not care much for 6550, preferring to instead go with KT88 if I am pursuing a sweeter tone, or Ei KT90 for a more neutral sound. One thing to be cautious about with the Czechoslovakian KT88 was that there was a period of time about two years ago where they were producing disastrous KT88. They would routinely fail within the first three months of operation. They had a difficult time maintaining consistent bias, and even sounded very, very erratic during operation. Russian tubes seem to represent a step down in sonics for me. But, if I was going to buy Russian tubes, I find Svetlana better to my ear.

I actually think we are on the same page Redkiwi. Just that our tastes, likes, and preferences may be different. The JJ/Tesla/Teslovak is a more polite KT88 in my experience. That is why I prefer it. Often, I like a classic tube sound if I am going to be using tubes. I guess the EL34 is the most characteristic of that sound, and the JJ KT88 can bring me closest to that. Other KT88/6550/KT90 may be considered more neutral, extended, or correct, but I cannot get over the realness and presence of the classic tube sound. Currently, my Jadis has the factory supplied Ei KT90. While many, many people feel this to be the most neutral, powerful, and best tube in terms of bass response of the big output tubes, I believe I will go to another tube(either JJ KT88 or JJ E34L) when it is time to retube. However, the process has been long in coming, as I can PERSONALLY vouch that the Ei KT90 lifespan seems to be tops in this league. I play the amp all the time, and the tubes show absolutely no sign of wear. In your case, a more forward tube might just be your ticket to happiness. But, if you do reinsert the JJ tubes, please submit your impressions. It would be nice if we could develop a "tube concensus" here on Audiogon, where everyone could simply come here and find the "probable" best tube for themselves the first time.