Like I said before, more than likely your cartridge has a failed suspension...due to age. Just because you have 'only' 350 hours on the diamond, doesn't mean that the suspension components are not worn out or dried up. Age of the cartridge does have something to do with performance IF the suspension has issues. How old is your Benz Ref s?? When you say it sounded distorted from the beginning, then I would question the set up and particularly the VTF...too high and you could have damaged the suspension over time. (Never mind what it has done to your records....:0( )
A new cartridge is definitely in order, IMO.
A new cartridge is definitely in order, IMO.