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Questions on KT150 tubes

Does anybody here have experience using that tube? Can you tell me how it sounds? I have a Primaluna DiaLogue Premium HP and it can use them but they aren't cheap. I'm running the stock EL34s and LOVE it but seems like this tube is all the rage. The Primaluna is unbelievable for its tube magic as-is. Also I wonder if the KT150 would last.

Also the best places to buy them. Not the cheapest. The best quality.
therealist

Showing 5 responses by bifwynne

bifwynne
2,206 posts
 
Ditto with what the "Wolfman" says. I have KT-150s in my ARC Ref 150 SE. When listening to music selections that I hadn't heard in a while (pre-KT-150), I am amazed by the difference.

Yes ... they are expensive, but ARC tells me that the KT-150s should last 50% longer than the KT-120s (3000+ hours as compared to 2000 hours).
bifwynne
2,206 posts
 

Agree with Joe.  But double that if you buy from ARC. 

It has been my experience that when I buy power tubes from a respected tube vendor I usually use, he can't get the matched power tubes to bias closely in my ARC Ref 150.  I've tried KT-120s and KT-150s.  Same story. 

At least with respect to my ARC amp, it seems as though ARC matches power tubes by focusing on using different variables.  Regardless of what ARC does, power tubes sourced from ARC bias within a few mVs of each other.  No so from the respected vendor.

BIF


 

bifwynne
2,206 posts
 

Dramapsycho posted:


But now that the KT150 has appeared. The KT150 offers more power and a longer life than any of the above mentioned tubes (about 10,000 hours in a cool running Primaluna amp). The KT 150 has killer bass slam and extension. The highs have a clear and very present sparkle (love the clocks in DSOTM). Imaging and sound stage are alive, full, detailed, and 3D. Jazz, classical, and rock listeners will really love this tube. Mids do not have the syrup that the EL34 has (a deal breaker for some listeners) but IMO they are natural, forward, and glorious. Truly, the KT150 is the tube of choice for those who want excellent bass power and extension, crisp highs, detailed mids (not sweet), excellent imaging, and long tube life."

Couldn't have said it better!!


bifwynne
2,206 posts
 

Wolf,

Before doing the SE upgrade to my Ref 150, I bought 2 matched quads of KT-150s from a respected tube vendor. 

Some pairs biased pretty closely; others were off by as much 6 or 7 mVs, which as I mentioned somewhere, is pretty close to the boundary of ARC's recommended range (between 57 to 73 mVs). 

IOW, if a set tube is biased at 65 mVs, the slave measured at 71 or 72 mVs. The max spec is 73 mVs.

Anyway, I only put about 200 hours on the KT-150s.  Am I offering them for sale?  Not sure.  ARC charges $200 per KT-150.   

bifwynne
2,206 posts
 
Upscale Audio comes though …. kudos!!

This is an update to some old posts about sourcing KT-150s from third party tube vendors.  Just bought 2 quads of KT-150s from Upscale Audio.  I had several telephone conversations with Kevin Deal and a UA service tech about the tube matching challenges I experienced in the distant past with my ARC amp.

Kevin and the tech explained that UA is using a third testing device (an Amplitrex or something like that??) that is set to ARC amp operating parameters.  Extra care and time is taken with matching ARC amp tubes.
  
So I tested UA out by buying a matched pair of KT-150s.  First set, … ok.  The tube biases in the set were within 2 or 3 mVs, which is as good as ARC matched tubes.  Second set, … the same.   Excellent.

I bought a 3rd pair.  The bias delta was outside ARC spec.  Called Kevin.  He said that it is best to order KT-150s in matched quads. UA can do a better job matching that way.  So I did.  Kevin kindly took the 3rd set back and refunded my money, … promptly.

I got the quad last week.  I was and am stunned.  The tube pairs match as close as or better than ARC matched tubes.  So kudos to UA and Kevin Deal for making me a satisfied customer.  

BTW, UA increased its price a little for ARC matched tubes.  UA spends a lot of time with ARC tubes and I do not blame him.  The price increase is de minimis for what we get in return. Just be sure to let UA know about tube matching concerns in the comment section of the online order form. Based on my experience, I am confident UA will get it right. 

Bottom line:  kudos to Upscal Audio and compliments to Kevin Deal.
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