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
The KT-120 is my second favorite tube in my Emotive Vita amps. My very favorite is the Genalex KT-77. No reliability problems with either type.

I think Atmasphere was more than a little unfair in repeating gossip about the KT-120 having reliability problems. Sure, there will always be the occasional defective tube and the unfortunate owner may vent his frustration. That's understandable. But after several years I haven't heard of any problems with the KT-120. By now word would have gotten out if this were true.
I have tried kt 120, WC 6550, GL kt88, JJ kt88, Ei kt90, sovtek kt88, I luked the 6550 WC best, just more musically convincing. In other systems this was not the case. The plate impedance is diffwrent for each tube so they are very system dependant. Try first in your system...Jallen
I have tried kt 120, WC 6550, GL kt88, JJ kt88, Ei kt90, sovtek kt88, I liked the 6550 WC best, just more musically convincing. In other systems this was not the case. The plate impedance is different for each tube so they are very system dependant. Try first in your system...Jallen
Old thread, but just ran across it. I have switched to NOS GE 6550A in my Bob Carver Black Raven 200 mono blocks. The improvement over the current production Russian tubes is incredible. I was going to try KT120s, but instead I bought another 14 NOS GEs. These are the favorite tube of Stu Hegman and Bob Carver and I see why. Bob loves to tell the story of when he asked Stu about Genelex KT88s and Stu raised his pinky and said "Watered-down British tea." If you are thinking of getting some new Russian tubes, now maybe the time. With oil prices so low and strangling the Russian economy, our response ( like the response if Jimmy Carter in 1980) may be to impose an embargo if Russia gets more agressive in Ukraine.