Do cartridges "dry" out?


I have 3 really nice sonus cartridges with low hours. Although they sound great, after several hours of use, they seem to get "tired" or "weak" sounding. If I stop an clean them throroughly they better. When fresh and clean, they blow away my Blue Point and Shure.
Someone told me that the parts in an older cartridge will dry out? Is that true? I never had this problem before with my pre-amp and don't think it's the problem.
Classe 30 pre with phono
Sota Jewel table with Jelco LMT arm
Sonus Bronze, gold and white cartridges.
elevick
I recall the Sonus cartridges were mid-priced moving magnets from the 80s. Suspension hardening generally occurs over the long term (years) not short term (hours) so I'm not sure what is causing your observations. Also, suspension problems seem to be more of an issue with moving coils than moving magnets (maybe because no-body keeps their moving magnet stylii long enough for them to harden). Sounds like dirt on the stylus but this should be heard as audible distortion. I guess you could try the Stylast treatment on your cheapest cartridge. If that works, what-the-heck, dunk them all in it!

keith
Phono cartridges use an elastomer (rubbery stuff) to mount the stylus in a compliant manner. All elastomers harden up with age. Sometimes (often) they can be softened up again by treatment with a fluid. This is how the car automatic transmission "tune up" products work. They soften the seals that have become hard and leaky with age.

So there is good technical reason to believe that Stylast would work. Auto transmission "tune up" stuff would probably work just as well, at a fraction of the cost. Put a drop in your cartridge and the rest in your car.