KT120 replacement
My ARC dealer already has some experience replacing the 6550c with KT120 and I could spend some time hearing the modified ref210's. They seem more powerful and dynamic that the old model and not by a small margin.
The existing specifications of the KT120 released by the tube manufacturer are very incomplete, they seem just a copy of some parameters of the 6550c with some higher ratings. Also, the usually released specifications do not show how a tube works under overload, a typical condition in many collective listening tests that are are carried at loud levels.
We can not discard the possibility that some people (even me ) claiming big improvements are just listening to fresh tubes versus aged, perhaps already out of specification tube they were still using.
As soon as I get some samples on of a KT120 I will measure the plate resistance and will post it.
My ARC dealer already has some experience replacing the 6550c with KT120 and I could spend some time hearing the modified ref210's. They seem more powerful and dynamic that the old model and not by a small margin.
The existing specifications of the KT120 released by the tube manufacturer are very incomplete, they seem just a copy of some parameters of the 6550c with some higher ratings. Also, the usually released specifications do not show how a tube works under overload, a typical condition in many collective listening tests that are are carried at loud levels.
We can not discard the possibility that some people (even me ) claiming big improvements are just listening to fresh tubes versus aged, perhaps already out of specification tube they were still using.
As soon as I get some samples on of a KT120 I will measure the plate resistance and will post it.