new to tubes


Just purchased a tube integrated that is powered by KT88s. The amp allows for swapping those with EL34s or 6550s. Would you be able to describe, in general, what the 'sound characteristic differences in these three tube types are? Thanks
facten
Thanks again guys for your feedback and clarifications. Saki70 the amp is Sound Quest SQ88, my first foray into tubes. I have only listened to it for about 10 hours so far and already enjoy it. Though I am keeping my Plinius 8200 and Portal Panche, the more I listen to the SQ it may have me hooked on tube amps going forward. The amp comes with Shuguang (Chinese Military tubes), seem good across the range; but I will be interested in hearing other tubes after the amp break-in awhile.
My bust , sorry for the incorrect info .

Facten ; welcome to the tube side !
Enjoy .
I'm late to this thread, but wanted to ask what brand of KT88 people like the most. I'm sure each brand has a different sound.