Has anyone compared K150 tubes and the stock EL34s in Primaluna integrated/amplifiers?

The KT77 is a good tube with plenty of bass however, I didn't hear it takes that long to break in.  I will take your word for it. Maybe the Mullards need more break in time but its noticeable that it doesn't have the bass output of the stock EL34 or KT77.  Aniwolfe what kind of speakers do you have?

The Cifte in my system do sound well however, they don't have the lushness of some other 12AU7's I have tried. I put in some Psvane in the front slots with good results. I will add that I got some GL KT88 and letting them break in and boy do I have some bass now.  Its too early to tell and will report back once they have more hours but so far the mids are nice. Not quite the stock PL EL34 but nice.

Thanks for the heads up on the KT77 :)  What are the characteristics of the Tungsram?  The Mullards in my system while sounding ok seem to really deaden the sound or its like someone placed a sheet over the speakers. I am speaking of CV4003 NOS Mullards I bought from Kevin at Upscale. Do your speakers tilt to the warm side or cooler side? I have Tyler Acoustics newer Highland series and the tweeter is very revealing without being bright. The rest of the drivers are SEAS.

I do agree the Cifte's have air and separation. Really good tube. I did replace the stock PL AU7's with reissue Tung Sol and they are breaking in but they helped with the upper midrange glare I was getting with some recordings.