sssibilancccce could also be related to improper VTA or anti-skating adjustments, or simply, to worn record grooves. If your TT has an arm height adjustment, to set the VTA, I'd raise the arm height a bit and see what that does. Likewise, playing with the anti-skate adjustment may help. If you have a cartridge alignment guage, it wouldn't hurt to check that as well. Even tracking force set too low can cause the symptoms you've described.
sssibilancccce...
Some used records I've picked up have ssserioussss isssuessss with sssibilanccce. OK, you get the idea. There's a wicked distortion on "s" sounds only. Otherwise the records sound great. What's up? I have a modest analog setup, well actually WAY modest consisting of the dreaded DD turntable, various isolation tweaks, low end Grado cart, old Rotel phono stage, and decent cabling (have used Harmonic Tech, Silver Audio and Audio Magic) but as it only occurs on certain discs I'm inclined to think it's not my gear. The only cleaning I'm doing right now is with a discwasher and homemade stylus cleaner. Would a vac machine take care of this, or is the record just junk at this point?