Any experience of noisy transformer on Jadis amps

Any transformer can start making bzzing noise. Yes it is the windings getting loose. I would bet a replacement is not available anyway, seeing ot is 17 years old.
(unless they have exceptional customer service and keep parts forever.)
You might try 'potting' it: that is fill the case with a thick polymer compound made for potting transformers... if it is in a case. It would fill the space and dampen the sound. (though it may NOT stop it from buzzing completely)
If it is open and out on the chassis top... I would try to press on the winding with my fingers to see what placement of pressure stops the noise. Then wedge something into the spot. Be careful not to scrape the insulation!

Elizabeth gives good advice. You should also check to make sure that a mounting bolt is not loose, or that there is not excessive DC on your power line.

Hi Guys!
I tried tightening bolts without success.
Have to take the lid of to see how it looks inside transformer, maybe I can see or hear clearer where (if windings are loose).

Many Thanks!