New KT150 tubes?


Has anyone any experience with these pretty new tubes. There are already one or 2 amps I know of, that use them. The review of one of these amps in a UK magazine suggested they were a little warmer and more natural sounding than the nearly new KT120's

The article also suggested they were a straight swap for KT120 based amps, with no adjustment necessary. They are more than twice the cost of KT120's, but still not too costly compared with NOS tubes. I know changing from KT88's or 90's to 120's. did require some amp modification. I have an ARC reference 75 and might want to try the new tubes at some point, ARC don't seem to have a customer E-mail service, to ask the question
david12
This is all very encouraging, it sounds like use is spreading, with or without ARCs approval. Personally I am in no rush and will carry on waiting for ARCs final word, I do'nt wish to void my warranty. As I suspected, it seems the 150's can give a big lift to the sound, but time will tell. My dealer and the UK distributor, still seem to have no view on it yet.
If one is willing to accept the responsibility (i.e. cost) for any problems that ARC deems due to use of an unauthorized tube then it is a no brainer. The problem arises when customers believe the manufacturer should assume that responsibility.
Djcxxx .... one other issue comes to mind. I'm thinking about resale issues. If I was interested in buying a preowned ARC amp, I would ask the owner if he rolled the KT-150s. All things being equal, if I could buy the same model, sans KT-150, I likely would. Having said that, this concern would be moot the moment ARC officially approves the use of the KT-150.
I have a pair of Ref 210 that have been upgraded to the KT120 with full resistor replacement by AR. My problem is: The tubes now have 2300hrs on them and I might need to swop them out. Do you think I can put the KT150 in them?