restoring an old SS amp . Distortion accured

[bak]

Hello folks,
i am putting my hands on a vintage Techincs SE 9060 , in my opinion a " slleping beauty" . At the switch on after probably more than a decade of not use it sound pretty good BUT i have a distortion like a BUZZ when high signal peaks occures . It is not the typical saturation distortion ( i am trying it with queit efficient loudspeakers.

I am suspecting one of the following problems :

Electrolytic capacitors need to be changed due the age
Relays on the output may be oxidated

Please i need your help and suggestion

Thanks

[EchoWars]

First things first...clean the signal path (switches and pots, including the relay).