Questions on KT150 vs KT120

@paulcreed ...I’m going to put the 120’s back in this weekend just to enjoy listening again. I’m hoping with more time they may come around and become enjoyable to put in every once in a while. Anyone know how long this break in period can be.

I just remembered something.  When I first bought my new QS Mono 120 amplifiers, the Co founder-designer told me that if I liked EL34s, to try the KT120s instead of the KT150s the amp originally came with. So, my local dealer gave me a discount on the amps if I'd give him the KT150s for his parts surplus, and he'd been running KT150s in these same amps original designed specifically for KT150s. 

I then picked up a quad of new TS KT120s.  Tried them for 30 hours and did not like them.  I had a return policy guarantee with my tube supplier at the time.  I STUPIDLY returned them. Later learned I did not give them enough time to settle in. Long story.  Then tried KT150s a while. Nice, powerful, detailed. I still wanted more musical midrange. So, I went back and repurchased a quad of KT120s. Checked them at 100, 150 hrs, and they started wearing in nicely, and I've kept them playing since.  Saved the KT150s stored, and then bought other quad sets of KT120s as spares liking them more after giving them more play time.  Re-check at 100, 150, 200hrs play time.  See if you start to like them more. I  sure did. :) 

I put the 120’s back in few days ago but put them 150’s back in last night to break them in during the week. Soon as I did same thing bright just not natural. I’ve been using a Z Cable/Clarity Cable Clear Focus power cord on Streamer and Dac. I Decided to try a Audioquest Hurricane and was a very nice improvement then put in a Clarity Cable Red Lightning it was even a little better from AQ. Will continue trying to make 150’s work, but was pleasantly surprised with results.

I forgot to mention I also tried a Snake River power cable which I also find on the warm side just like the AQ and Clarity Red Lightning. The Clarity Clear Focus is one of the most transparent cable I’ve ever owned it digs so deep and pulls out things in the recording you normally would not hear. So far not a good match with the 150’s, maybe too much of a good thing. Tubes are also a Problem with the 150’s I couldn’t pull the Telefunkens, Tungsgrams and Mazda’s out fast enough.