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
If ARC starts using them in their Ref series amps i would likely want to have a listen to a REF75 with those inside before making a decision on a REF150 with KT120's.
I would like to replace my aging Classic 120's although they were upgraded by GNSC in 2005. I am using 8 SED 6550C in each of them and they still sound fabulous. Just looking at getting something else in the ARC line with close to same power output but with fewer tubes.

Let us know what Kal says.
Thanks Knghifi, Paul's work is truly SOTA it just takes a lot of time to build them one at a time and there's no substitute for that...
As for ARC products I'm hearing such great things about the Ref 75 and I'm sure we would all like to know about the 150's in there too. Keep us updated...my guess/hope is that they will work??? and we all will be in for an even further treat. Good luck
I have the new GT200 Monos by TRL and have put the KT150 in place of the KT120 tubes. They blow them away. Being that the tubes have such large plates it takes a lot of hours to get them to open up. They are becoming the best tubes I have ever heard. The GT200 monos take complete advantage of the tubes. With the large power supplies and massive caps the tubes really shine. I had a few friends over and the two women actually cried on a piece I played for them. One comment that they made was " I want to stand up and applause". One mistake that some people make is they don't give them time to break in and they don't bias them high enough in order to run a signal through fully.Human voices are a dead give away. Give them time
Booboobaer - How many hrs are you talking about? I found with the KT120's they took at least 200 hrs to settle down.
I had a word with the UK importer at a small show over the weekend. He has tried the 150's in his amp and was'nt impressed. Good for a guitar amp, was his response, too rich, too much midrange bloom.

He said the 150's would be ok in the Ref 75, which I have. He thought the Ref 150 would'nt be ok. There would'nt be a high enough plate voltage to drive more tubes than the 4 in the ref 75. Just what he said, I have'nt heard the KT150's myself. I too would welcome feedback from ARC, I could'nt find an E-mail address to contact them, on the website.