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
Hopefully we may hear some definitive direction from ARC in the not toooooooooo distant future as to which models , if any , may be certified to utilize the KT150 .
ARC are currently not using this tube nor have they sonically tested or life tested it as far as I know. They continue to use the KT-120 for those amps designed to use it.
Thank you for your input Hifigeek1 .

May I inquire whether you have in fact spoken with , or had direct and very recent contact with ARC R&D on this matter ?

I ask as your comment ~

" nor have they sonically tested or life tested it as far as I know"

would tend to contradict what scant information we have at this time some of which purports to be from ARC themselves !

ARC is in the process of testing this tube. They are in the process of life testing the tube as well as sonic evaluations. They have not come to any decisions as of today. When I hear something more I will post it to this thread..
Gary (Hifigeek) -- does ARC still hold that the KT-120s have a 2000 useful life. I thought I read a 2012 review of the Ref 150 that quoted an ARC rep as saying the KT-120 tube life was considerably longer. In the same view, is the 6550 WE tube life also 2000 hours. I have 6550 WE tubes in my ARC front end gear.