KR Audio KT150

@tsushima1 okay, thanks for clarifying that.  I too am curious about the KT170s and future remakes of the KT150s we might see down the road.  

With my system I've had to tube roll quite a bit (25 different pairs) with my smaller input and driver tubes.  The goal has been to move the needle on sound with the KT150s to get them closer to what I liked about all of my former EL34 and KT88 tubes on other amps. I'm less into neutral sound and more in to finding that balance of tube magic and neutral, somewhere in between.   

Finding the right input tubes and interconnect cables has been an interesting venture, and [finally] now the KT150s are showing their real potential. Keeping an eye out maybe like others are, and seeing these KRKT150s shows there maybe more in the future.  To your point, have not heard the KT170s.  Will be looking for reports and chatter too. Thanks!   

Oh btw I added to your KT user bias point poll 

@decooney

My REF250SE’s , being just lately out of factory warranty, I would have given the KT170’s a run by now,  however they are way too Portly to site in the amps close quartered B7-99 sockets

Couple notes…I am a KR dealer and recently had a customer who had an issue with a tube that was DOA.  I had them in-stock for more than a year prior to discovering the issue.  KR replaced the tube, no questions asked and at no cost to me or the customer.  I have heard about issues 10 or so years ago but KR is not an issue in terms of warranty.  Just be certain to buy through an authorized dealer.  There are people that claim to sell KR but do not and will sub in other things.  
Regarding their KT150, last I checked they hadn’t made it for a while.  I had these priced at $800 a pair but they were not a fast seller.  I have note heard them.  
I will say, the KT88s are stunningly good.  At $250 a tube, they are not inexpensive.  I have two matched quads in a pair of Art Aufio Opus 4 monos and they took what was already a great amp to a whole new level.  I have also run Tung Sol KT120s and Genalex KT88/6550s in the amp and the KRs are dramatically better.  Tighter bass.  More detail.  Better high frequency extension than either the Tung Sol or Genalex.  They are pricier but I firmly believe I am getting better sound.