Jadis ja-200 vs ja500

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 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..  

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

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.     

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.