KT-88 in Conrad Johnson Premier 11a


I read some discussion about replacing 6550 in Conrad Johnson Premier 11a by KT88 may/will tighten bass and improve overall midrange and treble performance.

I talked with CJ and they said they never tried KT-88 in 11a (well I really doubt it) and it may not be able to bias KT-88 in it at all.

I really would love to try KT-88 in my 11a but I need to make sure I can bias it correctly... Any one got experience in it?

Thanks
Andy
hklai
I use the svelenta KT88s in my preimier 12s bias adjustment is pretty close to the 6550s,you can use them no problem.
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
Thanks everyone! I read some discussion saying KT88 needs to be biased differently on some amps as it works best in a slightly different current flow.

Anyway I am really tempted to try KT88... Artmaltman, which brands of KT88 did you try on your 11a and how would you compare them?

I wish I can try GEC if I had the money. =p I am choosing from Svetlana, Electro-Harmonic, or SED. I found on some tubes store websites that SED is re-branded Svetlana... but SED costs more. Anyone knows the story behind this?

Thanks!
Andy
Hi, Hklai:

Svetlana was a venerable tube manufacturer with a plant in St. Petersburg, Russia. Several years ago, a company in the USA named Sovtek purchased sole rights to the brand name
"Svetlana," as well as other famous brand names, such as Tung-Sol and Mullard. So now Sovtek makes and markets tubes labeled Svetlana which are considered my some to be inferior. Meanwhile, the original (real) Svetlana makes tubes labeled SED-C with a winged 'C' logo, and some older production SED-C tubes carry the name Svetlana on the boxes. Sovtek markets some tubes that are said to be musical, including the Electro-Harmonix KT-88. Go to the above link to see a photo of a real Svetlana SED-C KT-88.
Best wishes,
Jay
Correction: New Sensor markets Sovtek, Electro Harmonix, Tung-Sol, Mullard etc. Apologies for the error...