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
As an ageing cynic, really ARC have no interest in showing the 150's will work in the current Reference power amps. They have the reputation of bringing out new models faster than a Milan fashion house. I would put money on them having a range of Reference power products, using the 150's, within a year or so.
" Step this way Sir for the new super reference Power amp, the 120's are so last year"

An unworthy thought I know.
Cmalak -- I haven't tried the KT150 in my Octave V110 but I have tried the SED 6550 and the KT120. Both have very similar sonic signatures. When I was looking for SED EL34's a few years ago (had the Octave V70se then)I met with Jim McShane and he told me about the quality of SED tube taking a nose dive. He said that Arc was the largest customer for SED tubes. In fact when I got my V70 the SED 6550 was the stock tube with the SED KT88 as an option. The KT88 is a much warmer sounding tube.
As an ageing cynic, really ARC have no interest in showing the 150's will work in the current Reference power amps. They have the reputation of bringing out new models faster than a Milan fashion house. I would put money on them having a range of Reference power products, using the 150's, within a year or so.
" Step this way Sir for the new super reference Power amp, the 120's are so last year"
Anything is possible. New SE model, KT120 inventory too high, haven't decided if new resistors are needed ...

I have a friend interested in ARC Ref250. The only reason hasn't pulled trigger is uncertainty of KT150. He spoke to a big ARC dealer past Mon and dealer said ARC is very happy with sound of KT150 in Ref amps and should work fine without problems. But since ARC hasn't officially endorse using them, he can't officially endorse them either.

Friend is exploring other options so I think the uncertainty has some negative effects on sales.
At this point I do not recommend using the SED6550 (winged C).
Before production stopped, (the factory burned down supposedly), these tubes became very problematic. I only use the 6550we at this point.
And from another Costa Rican based corespondent, seeking advise, in respect of an amplifier to drive his Martin Logan CLX speaker,

"Problem solved.
You are absolutely right, following those who recommended to test the amp at home, I did just that and I found the ARC 150 to be just right in the sense that it gives me the full bodied presence I wanted, plus the prerequisite of better imaging and full range of frequencies. Like I said, I tested it and it's staying here. One more additional reason is the dealer brought it with the KT150 tubes already installed, so it made a huge difference. Thank you all for helping solve this little riddle and let me say I am happy. It worked great."