Need help with Jadis JA200

Though I have no experience with a JA200, my path down the road of other Jadis amplifiers has led me to the following opinions:
1) KT90 are a poor tube choice. The KT90 is a cold, sterile tube, which does not allow the magic of a Jadis to come through almost at all. Why did the company choose this tube? Well, they preferred the Tesla/Teslovak/JJ KT88 of the mid - late 90s, but the reliability of those tubes was such an issue that job number one is not to have the amplifier go down in the field

2) 6550 are not as good as KT88 tubes. Again, the KT88, in general, is a more romantic, emotional tube. You buy a Jadis to produce the romance and emotion of live music. It doesn't make much sense to use a tube which does not allow that

3) KT88 are a very good overall choice. The tube has a nice fat mid/upper bass that I like, with the sweetest presentation of the larger tubes.

4) EL34 are my favorite output tubes, with a midrange that is simply and startingly beautiful. The downside is that you are going to give up bottom end, to the point where it may be unacceptable. Eventually, through trial and error, I've found the key to resolving this is to find the right 12AX7 driver tubes. You can even produce thunderous bass by getting this right.

As an aside, the JJ K77 strikes an interesting balance between the EL34 and KT88. Its midrange is nowhere near as magical as the KT88, but it does trump most KT88 I have tried. And, the low frequencies seem to be as powerful as the KT88 in most regards, though they can be a bit bloated if other things aren't taken care of.

In conclusion, my choice for a Jadis is the EL34. However, if I didn't pick the right driver to account for the lack of bass, I'd go with a JJ KT77 (first) or one of the KT88 variants (secondly).

Gold Lion = Genelex re-issue.The "winged C"s were somewhat brittle in the highs.The JJs can be a firecracker-many difficulties and shipping them doesn't inprove things.The 88-98 is a little less "juicy" in that lower mids/upper bass range.Thus my suggestion for the Gold Lion;-)

Thank you for all your help. This has been very helpful and lots of information to think about.

Trelja, on Jadis site, only KT88 KT90 and 6550 are listed for JA200. I understand that EL34 and KT77 are quite similar but not sure if they would work in this case.

Also, where is a good place to buy from? I looked up a few places, tubedepot.com, tubestore.com, thecableco.com, vintage tube service, upscaleaudio etc. I only dealt with thecableco.com in the past and have been happy with their service but never bought any tube from them. Non of the local store here stock what I need in adequate number so mailorder seems to be the only way.Upscaleaudio seems to have a lot of praise around here but a bit difficult for international order.
Thanks

I used EL34s for years with no problems. Like I said earlier I did find the EL34s to be some what speaker specific. There is a guy in Chicago, Jim McShane, I always dealt with. Good guy. http://pages.prodigy.net/jimmcshane/

You should check to see just how old your Jadis amps are and whether the transformers in them are the originals (optimized for the KT88/6550 or EL34 types) or the newer ones, which may have been optimized for the KT90s. While all of these types may work with either transformer, you might be missing the last word in performance from the amps.

Trelja's descriptions of the sound with the tube types mirror my experience using the similar but less powerful JA80s. My favorites in the JA80s for the music I listened to (a lot of classical and large-scale symphonic) were the original NOS KT88s--6550s were sort of a brute force tube, lacking the beauty and finesse of the KT88s and EL34s, and EL34s just weren't up to driving my speakers in the deep bass.

I will point out that it does not pay to cheap out on tubes for these amplifiers. Every tube that I used in the amps other than the Genelex KT88s would start going bad within a year, while the Gold Lions were still going strong after 4 years. The best person for tubes in my experience is Andy Bouwman of Vintage Tube Services; his prices are not cheap, but with him you know that you are getting what you pay for (and there are a lot of fake tubes out there). I would be cautious with the new Genalex reissues, as I do not believe that they are as well made as the originals.

You have purchased a classic pair of amps with a distinct sound, I hope that you enjoy them as much as I enjoyed my JA80s.