Jadis 6550? (for CJ Prem. 12)

Jadis does not make their own tubes. Rather, like Groove Tubes, they relabel someone else's. I suggest you find out whose they use, and go with them. I am not sure of their 6550 supplier(I would guess Sovtek or Svetlana), but their KT90 and 6CA7(EL34 equivalent) is Ei, of the former Yugoslavia. These days Jadis is pushing the KT90, as opposed to 6550. Reasons stated are better power/bass response/tone/tube life.

Thanks for the information Randalleron! Personally, I use the Ei KT90s in my Jadis. Perhaps they use 6550s from the factory that produces the Golden Dragon line(Shuguang???). I have never gotten open sound from Chinese tubes, but have never tried Golden Dragons(they are supposedly excellent). Usually the Chinese tubes impart a very slow sound, as if a thick oil had been poured over the music(I am sure Jadis would not go for this type of sound, as they are not fond of "warmth"). Moving to European tubes seems to open everything up. I do not like the sound of 6550s, finding them inferior to: KT90s in terms of power, bass response, extension, and tone(besides the fact that KT90s supposedly are much more long lasting); and KT88s in terms of sweetness, warmth, and "glow". I prefer using KT90s in more neutral applications, and KT88s in more romantic ones. But, we all have our preference... Good luck!

One thing you may also want to try is HomeGrown Audio's version of KCAG. It is only $70 for 1 meter(terminated). It is the same as KCAG, only using solid core silver wire(as opposed to stranded). I find it better sounding than Kimber. Less edgy, metallic, shrill. Yet still accurate, detailed, and extended. Jadis doesn't recommend KT88, as they feel they are unreliable. I have investigated this, and found there was a period when Tesla(also known as Teslovak, and now JJ) KT88 were very unreliable. Recent production has been fine. I would first recommend getting the HomeGrown Audio cable, give it a 200 hour break-in(it may sound terrible even at 50 or sometimes 100 hours - there is an easy way to break in cable without turning on your amp, which I learned here on Audiogon). If you still find yourself craving the warmth, then try a set of KT88s. Also, will your CJ Premier 12 accept EL34/E34L/6CA7 tubes? I would e-mail Conrad Johnson with this and other questions. If you REALLY desire your CJ to sound sweet, warm, and romantic, the EL34 types are the way to go - classic tube. You would also be paying 50%(or less) for this type of tube(good now, and great in the future). What kind of speakers are you driving? Assuming you have an abundance of power now, you don't have to worry about what you'll lose when you switch. And they work beautifully with silver cables. Good Luck!