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
A little further information via 'Our man' In Costa Rica.

"Today, I went to see (and hear) the ref150 with the kt150... The owner told me it was the dealer who suggested the use of kt150, has only 62.2 hrs on the clock, but absolutely no problems... The dealer told him that an ARC representative told him it was safe to use them, he already tested a unit with kt150 with 3500 hrs so far and recomended based on his experience..."

Has ARC issued any guidelines, as yet, to their distributors and dealers with respect to this matter?
Or, have a couple of them simply 'Gone Off The Reservation'
And for the interest of members that 'actually' have a material interest in this matter, further comment from a guy in Florida running with an Ref75/KT150 combo~

" That is a good assumption. I have also heard that "when or if" they "sanction" the KT150s they will offer their products at different price points depending upon the tubes the gear is being sold with.

I am closing in on the 150 hour mark on my REF75/KT150 combination and can tell you this upgrade is a no brainer. First 10 hours expect a much fuller an rich sounding experience with amazingly fantastic midrange, but slight attenuation of the higher octaves of what you are used to with KT120s: BUT right out of the box, you know you have something special. By 25-50 hours of listening there is no attenuation of upper octaves and all sounds incredibly balanced with a richness and fullness I have NEVER experienced with a tube amplifier. When you get past the 100 hour mark, you will hear things you have never heard; literally. I was listening to BlueCoast ESE #1 Dayan Kai first cut with a buddy of mine. We have heard this cut many times as my buddy likes to use it as reference. My system is upstairs, my wife was away and my 3 dogs were downstairs. My buddy says, someone is breaking into your house. I laughed as he ran downstairs, my three dogs sleeping, all doors closed and I said, that is background noise of the album you are hearing for the first time.

Listening to Eva Cassidy, Live at Blues Alley, listen for the clinking of glasses in the background as well as the deterioration and raspiness of her voice as the album progresses. Pretty unique in the difference pre and post KT150s. As it turns out she was sick with the flu at this recording and she wasn't happy with the way she sounded, although I think it is sublime but you can clearly hear the progression. It was like listening to the recording for the first time.

One warning. These tubes are so good at resolving that all little nuances of digital recordings (especially if your speakers are capable below 40Hz) made from master tapes, not direct digital become noticeable. This presents a problem for some people while others love it.

For those of you with a REF75 and relatively efficient speakers, be prepared for your audiophile friends to shake their heads telling you that there is NO WAY that is a 75watt amp.

For those questioning whether or not to make the change, go for it and enjoy. The best 350 I have ever spent on audio, bar none."
Tsushima1, awesome review from your friend. Does this mean you are going to stop typing about the no-brainer upgrade and do it for yourself? What does "actually" mean in your first sentence? Is that to imply that if someone isn't sitting around wringing their hands about a set of new tubes, they just aren't living their life to the fullest? LOL.
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.