I used a variety of KT-88 and KT-90 in my Premier 11a and Premier 12's. They were all wonderful, so it is very much a matter of taste.
This is the only line of amps in my experience where I ended up preferring 6550 to KT88 or KT90. Usually I prefer the slight touch of ripeness added by these latter tubes. But CJ gear already sounds sweet with 6550's and the KT88 and KT90 were a little over the top for me by comparison.
But I don't think you can go wrong try ing it out, its a huge part of the fun of the hobby.
Art
This is the only line of amps in my experience where I ended up preferring 6550 to KT88 or KT90. Usually I prefer the slight touch of ripeness added by these latter tubes. But CJ gear already sounds sweet with 6550's and the KT88 and KT90 were a little over the top for me by comparison.
But I don't think you can go wrong try ing it out, its a huge part of the fun of the hobby.
Art