I recommend strict abstinence for your turntable.
Seriously, there's a host of reasons why sibilants ("S" sounds) may be distorted during vinyl playback. Most systems suffer from more than one of them, so nobody can provide a single, easy answer.
This distortion is usually called "sibilance". If you search for that you'll find a long list of threads discussing it.
Excessive energy or distortion in 5-8kHz range. I got rid of it by buying better speakers with soft dome tweeters. Highs are still strong and extended but "S" sounds are very clean and natural.
Bad pressing or poor tracking....due to either misaligned cartridge or worn needle.
Oh...and some cartridges can't track worth a crap.
Sibilance is usually caused by turntable/tonearm/cartridge
misalignment. Maybe recheck your setup.
If with other sources and/or all sources, then speakers, cables,
speaker room placement, plus a lot more.
I would like to thank everyone for their kind response that is except for response from austinbob, I swear some people are just, well you know.
Tfile, when you float the tonearm, when it is level, move the counterweight so that the cart end is slightly up higher than the counterweight end. Set the tracking force and anti skate, then play the problematic album and listen to determine if it sounds better or worse. Also remember that some singers have a lisp. Best of luck.
I am going to thank austinbob for you. Thanks Bob.
As you might surmise from the responses so far, just about anything in the reproductive chain can in one way or another cause sibilance. It's difficult to analyze the cause from afar, but can you say whether you hear sibilance with CDs? If not, that would more or less let the speakers, the amplifiers, and the linestage of your preamplifier off the hook. That leaves the phono section or phono stage, turntable, tonearm, cartridge (or tonearm/cartridge match), or the LP itself.
Then, can you say whether you hear this phenomenon on all LPs, or only a few?
Sometimes if you lower the VTA it will cure that problem! Give it a try,you have nothing to lose.
Some singers "SIS" the Ss, with "natural sibilance" in their vocals.
I have a lot of experiance dealing with these types of problems. I can give you some ideas, but you need to list your entire system (make sure to include cables, tweaks and anything similar." Also list some of the albums that gives you the most problems.
If all is adjusted very well, it is often a cartridge problem. Some boost this frequency range. I had same prolems with my Lyra´s, now with an EMT the sibilants play very well.
The problem is usually a combination of VTA and VTF. Try lowering the tail of the cartridge slightly and also increase your tracking force a little. Should help immensely.
+1 to Lewm's and Zd542's posts.
Everyone else is just guessing. One or more of these guesses may be correct for your case, or not.
As I previously posted and as these responses make clear, there are many possible causes. Which one(s) apply to your situation is unknown and unknowable without additional information.
In my experience what you are hearing is an artifact of mist racking. Some records are pressed "hot" and sibilance is unavoidable. Goodxalignment and set up are key and having a cartridge that tracks well also helps
Everyone else is just guessing? You have to start somewhere. Maybe Thefile will let us know who was right when the problem is fixed.
Time to upgrade turntable and cartridge.
Ha-ha. There has been a veritable torrent of responses and suggestions, whilst the OP is probably off doing something more useful (to him). I say, let this thread die until we have more info.