KT-88/ 90 choices to replace my new stock tubes

I am trying to decide on one of these tube types for a new pais of quicksilver V4 amps I just bought. The stock tubes sound good, but I feel they can be improved upon. My frontrunner is the JJ tesla KT 88 ( around $75 a pair) , having had good results with this tube previously with another amp. I am also considering the EI KT-90 , which I heard was quite good with the exception of the newest ones( mark 3 perhaps). I am open minded and the JJ tesla price range is fine, but I dont want to spend too much over their asking price.Thanks in advance.

Electro Harmonix KT-88 or 6550.
i'm running ei kt90 type iii in my monoblocks. there are 8 tubes per amp and the bias setting is for all tubes so it is so low that i've never run into the glowing plate issue. that's not to say that the kt90's aren't problematic, but even if the plates in all 16 of my tubes of misaligned, they still sound significantly better than the electro-harmonix kt88's they replaced.
The Penta/Shuguang closed-plate KT88SC @ $29 is still getting raves from users on the Tube Asylum. Mine sure sound good.


I second Jeff's recommendation. The Penta Shuggie's are fabulous. Just be sure to request solid plates without holes.
I had 6550s in my integrated amp when I bought it, but replaced them right away with EH KT88s. The sound was much fuller and in my opinion more enjoyable. FWIW
I have had the EH KT88's and was not impressed. I think the Chinese made Valve Arts that I use sound great though.
Thanks for your suggestions, isnt the factory tube in the quicksilver V4 pronounced Shuguang as well. Is this penta one also a chinese tube, and if so would it most likely be superior than the stock (shuguang-I think) KT-88 in the quickies. Where can I find this penta shuguang closed plate KT-88 SC, and I wonder how it would compare to say the KT-90. I know the KT-90 is said to increase the power in the V4, but will they retain the lush and textured midrange of the KT-88.
Use KT90's and your midrange may suffer somewhat. The kt90 is a more alive sounding tube. If you like to go in that direction then the kt90;s are for you. I had good responce with Valve Art kt-90s. Valve art kt90's sound great in Hurricanes. Kt 90's (series 2,) sound best in VTL 300 (need a boost in highend dynamics) My rogue Zeus Electro Harmonix are best, ect.I woulnt be too concerned with power output.
Ive found out of all these listed amps i sold them all and kept a rogue Magnum 120's, MUCH faster and less tubbey then the lot. Hope this Helps.