We have a very old home amplifier, which has long been heavily scratched and go the right speaker repeatedly bass lost. Polluter is the volume-sliding potentiometer. The whole looked like a loose connection from Poti, because he probably could not produce for both channels simultaneously contact. After some Internet research in hi-fi forums I've often read of this Oszillinspray what probably should spend wonders, but unlike other sprays nothing etches. Okay, you can try so times.
When it arrived then, I quickly dismantled the system, then sprayed on all pots and interconnects and the regulator a few times back and forth (is so on the can instructions) and reassembled. Lo and behold, the scratching noises and jitters are gone. If it still holds so there is absolutely nothing to complain about.