Jadis ja-200 vs ja500

Update: Bought old Jadis JP80 and connected it to the JA30. WOW! Right now I feel no need for a bigger Jadis amp. Amazing resolution, depth, bass, dynamics, emotion. So it seems like the problem was in the preamp, not the amps. Thanks for all responders.

Congrats on your new addition. I know this is the ideal pre for all jadis' amps. 


Well I was hoping to locate a  used jadis Preamp, at a  price I can afford, No luck, The dealer in san Antonio explained *sure not often you will see a  used jadis pre for sale, ,,its like you, will you sell your DEFY7??*, My answer was no, Especially after I have now modded nearly the entire unit minus  the DIODES,,which I will not.
And the 4 blue Electrolytic caps, the 2 big ones on top on amp and 2 inside, these were made by PHILIPS,,,these 4 are worth their  weight in Gold. The tech changed out all caps, and after listening, I went straight back to the Philips,, The Nichicon sounded unmusical, dead compared to the original Philips,,The other caps we swapped out, for F&T's, Mundorks, and Nichicon's. 

Also want to let Jadis owners know, power tubes need be matched as closely as possible. 
Jadis has only 1 set bias screw for each row of tubes. 
Tubes need be well balanced.
also each amp from Jadis is designed arounda   certain tube in mind. Like the Defy7. Sure it will accept KT90, KT88, but the ideal tube for the Defy is the 6550. 
Which I have on order,,aftera long and wasteful journey of rolling power tubes, I am right back where I started, back to 6550's. The original Svetlana I sold off, 12 for $300,,,late 90's NOW, Now I will be purchasing 12 new stock for $500.
If my hunch is correct, the Svetlana 6550 is the best power tube ever made. 
I will not know until the amp is finished modding with new Takman Metal resistors, and the new Svetlana.
I will post a  YT upload on my topic, Jadis Defy, part 2.
I havea  long list of mods and upgrades  to go over inside the Defy , also a  DIY power cord I made myself anda  new DIY interconnect with pure copper terminals (if my tech guy can solder the connects without meltdown of the plastic sleeve).
On resistors, stay with the original Takman metal, Do not go with carbon film resistors,, The carbon film lacks the brilliance of the Takman Metal resistors. 
On coupling caps, go with Mundorf SESG = SilverGold Supremes. 2x's the price of the economy line the EVO Oil, but far superior sonics, The .47 uf priced at $45.
I will go over everything in my next YT vid.
My YT channel is blocked for leaving comments, as the YT/Google mods have my page permanently blocked due to a  CV19 upload that i made. 
Regretfully  that restriction is permanent. 
But you can leave comments /questions on my Defy7 part 2 page.

I will add a  new cayin pre and will continue my search for a  used Jadis pre. 

Update: Bought old Jadis JP80 and connected it to the JA30. WOW! Right now I feel no need for a bigger Jadis amp. Amazing resolution, depth, bass, dynamics, emotion. So it seems like the problem was in the preamp, not the amps.  Thanks for all responders. 

well my Defy7 is out of commision at the moment,,I did some things the Defy is not at all happy about and so shut down,, 
Returned the new SVETLANA 6550's w/o hearing them, as i took my tech guy here in New Orleans advice , which he suggested in  look into the Gold Lion KT88's. 
after hearinga  YT vid with GL 88's, WOW, what a  stunning sound. 
So retured the 6550's witha a  $100 restock fee added on to VIVATUBES order,,and  once return is completed will order 12 perfectly matched 12 (4 sets of trios) from Vivatubes.
also asked randy to see about swapping some resistors , will go with RIKEN Resistors, as they have copper leads, others have aluminum leads. 
Just the fact this lab uses copper as leads lets me know they alos put attention in the actual resistor as well.
Won't change them all, as its about 50 resistors. 
Just the critical ones.
Right now amp is out of commision, both channels.
also wish to say this Defy's trans run slightly warm center and 2 side trans, run cool/cold.
Tubes put out somer heat, but nothing excessive, as i placed a  window unit in my room, and on hot days , will run it  all  night with door closed, so in the morning for listening,, the walls/room is ice cold,,and ready for 4 hours of listening,,when i break for breakfast, i will shut system down and restart window unit.
I can always start up central air, But really heat is not that much ofa  issue,,Now witha  JA200/500, with 24+ tubes, yeah I can see heat would bea  issue. What i would suggest is have your handy man install a bath vent in ceiling to suck hot air out  through attic vent. But then you have the vent running noise,, so not a  option,, How about  makinga  hole in ceiling, and placing a  tiny fan in attc, over the hole, you will not hear fan run. This to me is the best option. 

@taviran I would consider the JA80Mk2. Not going to be a heat engine like the other amps up the line (200 and 500) and will give you the ability to hear the new KT150’s along with auto biasing and enough power to drive your speakers. IME, the best sounding Jadis amps are the middle to low power models. If you can get away with less power, consider the JA30Mk2.( more power than your current older version JA30).

Well, not sure about the sensitivity and impedance figures for the ESPs (their website has no information about their models, from what I can see), but I'd say if you want that sense of ease the 500s might be your ticket.  When I heard them they were driving mbl 101s (the original model) with no strain, so I'd say they could drive just about anything.  But, despite not being pure class A, they will throw off more heat than the 200s, simply from the larger number of tubes in them.  The setup with the mbls had the 500s in a separate room to keep the heat down in the listening room. 

Thank you, guys. Very good comments, just what I was looking for. 
Rcprince, the JA30 is indeed a wonderful amp. I tried it with kt88 and El 34. It sounds amazing on my quad 57 (for those looking for a good match with those), but on my ESP Bodhran, you hear it is getting stressed at times. Besides, I have preference for powerful amps. Even when I owned the Klipsch La Scala with its very high sensitivity, I always liked it better driven by many tube watts (well, actually it was my wife who set the tone here). Smaller amps can have higher resolution but they always lack, for me at least, the sense of ease that big amps have, which is more like the real thing for me.
Cheers.     

Big fan of Jadis here, , Owned the JOR  with EIkt90's, a  tube which prsented music witha  live stage presentation,,but the EI's had this screetchy high presence = disortion,, wish i had rolled the 1 AU and 2 AX's to Teles , That lil amp had much more potential. Just want the unique and exclusive Jadis fan club to know i recapped my Defy 7 with M SESG (Siolvergold Supreme) .47 uf vaoues, 12 count,, and made a  huge sonic gain in bass/mids/high resolution. 
Running chinese 88's, with Tele's in the front section. 
Vid is posted on YT, 
Should have Defy back today with all new electrolytic caps, about 25 caps, includeds the 4 huge caps as well.
Randy Cohen my tech guy in old historic St Rock area of New Orleans, swaped his electros in his Golden Tube amp and noted a  very nice sonic gain,,so I figured the amp isnear 20 yrs now (very little useage, bought on audiogon in 2008 from a  guy in California who had JA200's, and so never used the amp, mine only recently up N running 2019, 20 yrs old, only1 yr low hour useage). 
Anyway,, also changing all posts, speaker, interconnect, to  100% pure copper posts. 
Just madea  a  pure copper poer cord for the 110 amp.
All these mods will be shown on my YT upload, as soon as i get amp back. 
I would not say the amp is modded,, basically upgade over Jadis's stock caps. 
Here is the Defy's new M caps
https://www.youtube.com/watch?v=-viI0SYQHko&t=1500s

I agree with zipost; I felt the 200s had more finesse and character than the 500s, which were more a brute force amplifier.  Plus, with the older Jadis you're looking at, the JA200s were auto-biasing and could use tubes other than 6550s, while I believe the JA500s were not auto-biasing and you had to use 6550s unless you got a tech to change the bias.  As an aside, I think the best-sounding Jadis amps were the lower-powered JA30s and 80s; if you don't need the power for your speakers your JA30s would be difficult to beat--you might want to try using different tube types in them (EL34, KT88) and different brands of driver tubes to tailor the sound to your liking..  

i had both ja500 and ja200,  Side by side comparison, Ja200 is a sweeter amps and more organic.   The ja500 is a much powerful amps,  inefficient speakers 86 db and below, will work well.  Both amps are totally different in sound quality and application.  Personally, i prefer the ja200.  

I had used Jadis 500 from 2000 to 2002 to drive B&W Notilus 800.

It gave the most powerful and deep bass in my listening room.

But I could not tolerate too much heat in the modest size listening room.

Thus I let it go.

No experience of JA 200.

Now I am happy  to drive efficient speaker with SET amp.