Questions on KT150 tubes

My KT150s have been in my amp long enough to erase the  memory of the tubes preceding them.

2000 hours on 120s seems to be about half or less than I got on mine and I had my ear on them looking for any sign of age near their end, and removed them as soon as I detected any tonal weakness (which was minimal but it seemed clear they had done their job)…I bet they had 5000 to 6000 hours on them, and I expect the 150s to last at least as long so we'll see.

I also own a Primaluna Dialogue Premium HP integrated amp.  I play vinyl on my Pro-ject Extension 10 and listen through the Volent VL-2 monitors.  I bought the Primaluna with the stock EL-34 knowing that I would swap all the tubes out upon set up.  I did.  I replaced all stock Primaluna 12AU7 tubes with NOS Telefunken.  Now I have a HUGE soundstage, incredible detail, and 3D imaging.  I replaced the primaluna stock EL34 tubes with Shuguang Treasure KT88-Z tubes.  Wow!  Talk about real bass slam!  These KT88s also offer very extended highs and a natural mid (female voice).  Several LAOCAS friends have come over to the house and have thrown everything they had at the system to find fault with it but to no avail.  Very happy with this tube set up.  I did run the EL34 tubes to compare with the KT88.  While the mids in the EL34 tubes were very lush there was a distinct lacking of real bass snap.  So, I am still searching for the Holy Grail of sound -- like we all are.  I spoke with Kevin Deal at Upscale Audio (Primaluna importer) and he said that he is running the KT150 tube in his Primaluna Dialogue Premium HP integrated.  Kevin affirmed this thread -- that the KT150 has incredible bass slam, very well extended highs, and well tempered, natural (not sweet) mids.  Because the Primaluna runs the power (output) tubes so easy (8 tubes for 78 WPC vs. the 4 tubes in the Ayon Spirit III) he says that they may last 10,000 hours.  So, for the money the KT150 seems the tube of choice.  Just hoping that Santa reads this post!

Lots of amps with 8 power tubes seem like nice things, and I've lusted for that Cary 120 amp for years (I guess after a Cordesman review), but doubling my power tube cost and amp heat output (I think even if tubes are driven less hard they're still little space heaters…unavoidable) is somewhat off-putting, although if a really great deal on a 120 came along…hmm...Besides, my "el cheapo" (seriously) Jolida sounds so good (dynamic snappy tube power, inaudible noise floor, accurate tone) I don't mind keeping the damn thing for a long time, thus freeing up cash for the "next great power tube" outbreak. 

I have a PrimaLuna Dialogue Premium (non HP) running all stock tubes. When I bought the amp I had Kevin send some TS KT-120's. After running the EL34s for awhile breaking in the amp and tubes I switched to the 120's (burned in by Kevin).  Definitely a difference but once I got a feel for the 120's, not sure if I am liking the overall sound. The 120's have a midrange glare or upper energy I am not finding pleasing so instead of buying input tubes to offset the midrange energy, I put the EL34 back in and the midrange is very very pleasing.  So I am not sure if the KT150 midrange is a lot better than KT120?  If not, proceed with caution. Also Kevin told me that the 120's over the EL34 you will gain 1db so if your looking for power he basically said its not worth it. I guess what I'm saying if you like the sound with the EL34 then you may want to think long and hard about the 150's. This is of course if the 150 midrange isn't leaps and bounds above the 120.