Do we still need 6550 or KT88 tubes?


I would like to learn your opinion and experience with KT120 tubes.

Considering that KT120 match 6550 or KT88 based amp (is a direct replacement), how do you like the sound of KT120?
Do we still need 6550 or KT88 tubes?
Do we still need to pay for NOS power tubes?

BTW at the moment a KT150 tube is announced. Should be even better than KT120 and could be interesting upgrade for current KT120 owners.
milimetr
Aren't amplifiers designed specifically for the KT120, or are all KT tube sets interchangeable?
Many of the older 6550 based amps cannot accept the newer KT120's. Presumably, the new KT150s would also be incompatible as well. So, to keep these amps alive, i think we will need to keep at least the 6550's going.
Hi Xti16

I contacted leisure-audio about the Shuguang KT-120s and they quoted me a price of $199/quad. I haven't ordered them because I just don't have the funds and honestly am up to my eyeballs in all sorts of KT-88, 6550 and Tung Sol KT-120 tubes. I think I've spent just as much money trying various tubes for my Jolida than what I originally paid for it. Oh well the joys and insanity of tube rolling...
Jedinite24 - I think I spent as much on tubes as my Octave too. Here I thought I was the only one that's Nuts.. LOL
Jedi, even though we are using different amplifiers I'd like to hear your impression of the tubes you have used.