6550 tube vs KT88

Bombaywallh  slashing of my comments was spot on, back then I did not know what i was talking about in all things tubes. 
I am still learing,,but making  costly mistakes...Very long story,,but here goes,,I bought a  used Defy on Agon some years ago,,had Jadis's recommended tube the 6550 in the amp,,w/o listening to the tube,,i sold the 12 off and bought kt90's, Then sold those off, bought kt88's, (now running) and decided to buy KT150's fora *more robust sound/bigger sound stage** Wrong,,Now am selling off the KT150's (gonna takea  hit) , will hold with the KT88's ,,but will also now REBUY the 6550's..
yeah , going around in circles.
Just heard a YT vid of KT88 vs 6550,,I loved the mid/highs of the 6550,,the tube originally placed in the amp by Jadis,,,
I really think its the best tube for the amp, and for my classical midrange.

wow, i posted this topic some,,,14b years ago,,and comming back yet once again to finally finsih the shootout,,talk about time delay.
I am now locking these 2 supreme midrange cantors in battle.
The Defy had 6550’s, never listened to them,,I assumed the 90’s were superior,,so yrs later (amp sat up for 10 yrs as, i had no cash fora good preamp til only recently 2019,,amp bought in 2008),,so anyway,, went from kt90’s in 2019, to kt88’s, 2019/2020, now kt150’s for 2 weeks, now back to kt88’s,,and about to buy some used (new? bulk lots) 6550’s.
all my comments/opinions above are null and void, all my ideas are completely in-accurate, and invalid.
I like uru975’s post,, the YT vid did seem to show the 6550’s has a upper mid/high FQ clarity/sparkle that the KT88’s lack. as far as **Kt88’s superior in details** I have doubts that the 6550's  lack such details as expressed in the 88 resolution....,,,My comment the 88’s lack bass is completely inaccurate, 88’s have super bass. Bombay corrects this faulty opinion in his July 2006 post,
88 ’s have gorgeous bass resolution,,and reveal details of mid fq’s, but as i say,,will the 6550 offer equal mid fq details , PLUS a huge bonus of sparkle and a clean open *Live stageing* of vocals?? as did the JOR KT90 set up???
(But the EIKt90 has a screetchy high fq distortion,, yet the mid fq’s gavea true live muisc show right in your room.
This is what i am after now.
the Defy surely adds more fullness vs the JOR,, all i need do now is try to match the JOR/EIKT90 *live muisc show* feel.
My hunch is the 6550’s will approach this experience.
read Dentdog’s July 2017 comment.

https://forums.stevehoffman.tv/threads/output-tubes-how-do-these-sound.683052/