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
Let me clarify, Alon in now Nola Speaker. KT-150's are still in life test with over 4,000 hrs on one set of tubes. This is good news. I'm sure they will be a drop in replacement for ARC amps that came from the factory with KT-120's. That being said, I'm still waiting for the ARC engineering dept. blessing. Hopefully it will be soon.
I could imagine there are a number of people who are running KT 150's in their REF75 (or other amps) but would not want to volunteer that information in a public forum for fear of voiding their warranty. Knowing that Carl Marchisotti has made the switch and is happy is enough to try it and upscale audio and others sell matched quads of KT150's. The real issue for some may be whether
they are willing to break the principle of their warranty with ARC and use something (even if its safer and better) that is not approved. I myself have cut the tags off my mattress though the warning says I would void my warranty to do so.
Ariess ... a related issue to the one you just mentioned pertains to resale. My ARC Ref 150 amp is used. I'm not sure how I'd react if I learned that the prior owner used KT-150 tubes if ARC had not blessed their use as of the date I extended an offer. Of course, if ARC sprinkled pixie dust on the KT-150s by the time I was ready to make an offer -- then no harm, no foul.

As an fyi -- ARC recently told me KT-150 life testing continues. Hopefully, I will survive ARC's life testing process. Seems like it will take a life time. :)
Just to be fair, I only recommend and use tubes from ARC. They are 'properly' matched and tested for at least 24 hrs at RATED VOLTAGES prior to being shipped. ARC products are too expensive to play Russian roulette with.
As an fyi -- ARC recently told me KT-150 life testing continues. Hopefully, I will survive ARC's life testing process. Seems like it will take a life time. :)
Bifwynne (System | Reviews | Threads | Answers | This Thread)
Wow, you ask ARC? Didn't know you're a CERTIFIED FREAK-IN AUDIO RESEARCH TECHNICIAN?