I think Rcprince is the person you should listen to for help in the New York area. He is VERY knowledgeable in regard to Jadis. If the problem is a resistor or cap(may also be a faulty connection), you might want to do a parts upgrade while the amp is apart. There is a shop in Philadelphia that used to sell Jadis. He stopped carrying Jadis last year. Seems that the US Jadis dealer network is all but gone. He reports his issue is with the product support for US customers. His stated opinion is that the sound is impeccable, but the support is abysmal(hopefully, I won't have to find out firsthand). I have no experience on their quality of service, but the owner says they are excellent(would he say otherwise...). If all else fails, and you don't mind driving 90 minutes, I could refer you to him.
JADIS DEFY 7 SPIT SPUTTER
I AM EXPERIENCING A SPIT AND SPUTTER SOUND FROM THE LEFT CHANNEL OF MY Defy 7 amp after it warms up for an hour. this is not tube related. When I change left channel signal tubes with the right channel signal tubes, the noise stays in the left channel. All other components in the chain have been checked out. Any advice would be appreciated. thanks