Questions on KT150 vs KT120


I’ve been using kt120’s on a VAC, CJ and Audio Hungary for a long time but thought I would give the 150’s a shot on the Audio Hungary. I’m not really enjoying the 150’s like I had hoped. I’ve found they are very dependent on signal tubes, running old Mullard’s to tame it down still not as musical as 120’s, very hifi. Anyone found this to be the case for you. Is it true it needs over 300 hrs to settle down.

paulcreed

Thanks decooney for explanation, I’ve always been a fan of el34’s and el84’s but these 150’s are very detailed with big bass but that doesn’t make me want to listen for very long. 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 like the KT150 tubes, the KT120 tubes sounded a little tipped up in the treble to me with a touch of grain. 

When I had the Audio Hungary a50i, I too preferred KT120s over the 150s. They just sounded more musical and engaging. Makes sense because the designer voiced the amp with KT120s. 

@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.