upgrading JADIS JA-200, JPS2 and JPS3

The problem with upgrading components in a Jadis piece of equipment is that the company really designed a lot of its models around the component parts they use in them, particularly the older units. When you start to modify it, you can put in capacitors, resistors and the like that are "better", but the resulting sound won't necessarily be a Jadis. Many of the modifications done back in the 90s were like this; at least one of the regular posters on these forums had some mods in a used unit he purchased un-done because it was not the Jadis sound that he was looking for.

The only mods I made to my Jadis JP80 and JA80s were done by Andy Bouwman of Vintage Tube Services, back when Andy was doing his "Romantic Era Treatment" modifications (I don't think he does them anymore). These were the only mods I've heard to the equipment that managed to keep the Jadis "sound" intact--in fact, they probably made the sound even more luscious, grainless and natural. I also did have Andy put in some Audio Note silver oil capacitors as by-pass caps in the preamp, and some vintage oil capacitors in the amps; we liked the changes made by those (one listener remarked that my JA80s as so modified sounded as close to SETs as a push-pull design could).

So you can mod, but at your peril. I would go for capacitors like the Audio Notes if you want to try that, because Audio Note parts tend to be consistent with the Jadis sound. And you can always try some tube-rolling to change the sound of the units. If you want more detail, sheer transparency, dynamics and hi-fi thrills, though, I'd suggest using a different brand of components entirely.

Andy's principal changes were in using vintage resistors throughout the units in place of the stock resistors. He did not change any capacitors, except in the amps (where he put in a couple of vintage oil caps), and I'm not sure where they were used there. The AN bypass caps, as I recall, came just before and after the attenuators in the preamp; only a few were used, in areas that Andy (a) could fit them--they're large--and (b) felt they would make the most difference. Jadis used to use their own caps in the preamps (they were black) till the early 90s, then they switched to Phillips caps (blue), which were reputed to be a little more transparent.

Since the JPS2 is essentially the line stage of the JP80 (not sure how the extra tube for the CD input fits in, though, if you have it in your preamp), Arthur's mods for the JP80 should be applicable for that unit, though I'd want a qualified technician to confirm that. If your hearing and listening biases are similar to Arthur's, you might like the difference.

What is the JPS3? Is that a standalone phono stage? Never saw it here in the states.

I thought that was what it was. Interesting, you have as many chassis to deal with as I do with my JP200MC! And I don't even use the phono stage in the Jadis, unless my outboard phono stage I have is out for updates.

I have gone without mods to my JP200 (it's already a very rare unit, as it is one of only a few that uses EF86 tubes rather than 12AX7s), and I already mentioned earlier the mods I made to my old JP80 and JA 80s. I liked the Audio Notes because they were extremely liquid and grainless, similar to their better equipment, but they might not be your cup of tea. Perhaps there is someone else on these forums who has tried some of Salvatore's mods?