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.

fjn04
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.

http://www.pentalaboratories.com/product.asp?dept%5Fid=5020&pf%5Fid=KT88SC+SHUGUANG

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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.