JADIS JA80 with 6550 or KT 88 or KT90 ?

My Jadis JA80 was built in April 1999 and came equiped from the factory with eight 6550 valves.

Before deciding to buy a new set of tubes, I would like to know some opinions about the advantage or inconvenience of using the KT 88 or the KT 90 tubes in my JA80.

Is there any experience of using these tubes (KT 88 or KT 90) in an amplifier designed from the factory to work with 6550 tubes?

Many thanks for your cooperation.
I have had these Amp's before,Best of the Jadis line of amps. Musically speaking. (IMO) And have tried all of the configurations you are speaking of. In my personal taste, and or ears. The "6550's" tend to offer better bass, controll, and depth of field. But TOOB's are cheap enough to try all the above. Find the ones that's sound best to you and sell off the ones you don't enjoy as much. Forget all that "Golden Ears" crap! enjoy the ones that sound best to you..Hope this helps? For a great place to purchase? e-mail me. I can tell where to go, and offer you more advise, and save you $, and time.
Many Thanks for your advise Mang53.

After some more opinions I hope to receive, I will come back to you.


you may want to try some EL34s' as well. I use EL 34s' in my JA 30s' and Ja 200s'. I haven't tried any KT88 or 90s' but I really don't like the set of 6550s I have for the JA200s. The 6550s have a hard edge to them.
Good luck.