Just googeled kt150;s. seems someone with a Conrad Johson rolled to KT150s with no issues at all.
Right now i had him bias for kt90's and sold those off, and now running kt88's with the same bias point as for the 90's.. I did not want to spend another $250 for rebiasing a tube just a hair fraction off from the previous tube,,now with the 150's, i can see the bias as practical vs the current kt90 bias point. .
https://www.conradjohnsonowners.com/viewtopic.php?t=713
Right now i had him bias for kt90's and sold those off, and now running kt88's with the same bias point as for the 90's.. I did not want to spend another $250 for rebiasing a tube just a hair fraction off from the previous tube,,now with the 150's, i can see the bias as practical vs the current kt90 bias point. .
https://www.conradjohnsonowners.com/viewtopic.php?t=713