courtesy of one of our favorite mastering engineers:
My Record skips or sounds distorted…

If you are having a problem with a record skipping or distortion, here are some things to check:

1. Check and adjust, if necessary, the stylus pressure.  It is usually best to use the manufacturer’s highest recommended pressure, but no higher.
2. Check and adjust anti-skating pressure.  This is done differently for every tonearm out there.  If you use a blank disc to check, the arm should have a slight outward bias (toward the edge, not the center, of the record). This is because the groove adds some “pulling” bias to the equation.
3. Make sure the cartridge is aligned properly in the head shell, and that the shell isn’t twisted in the arm.  The first requires an alignment protractor, usually supplied with the arm, and the second means making sure the top of the head shell is parallel with the record surface as you look at it from the front. 
4. If these adjustments don’t work there are two other factors: stylus wear and age.  If the stylus is worn it can cause distortion and skipping, but if it is old the odds are even better that it is not tracking properly.  As the stylus ages the compliance hardens.  When this happens it is incapable of following wide excursions.  This is the single most common cause of skipping.  If you have had the same stylus for years, whether it has had a lot of use or not, you are probably due for a new one.
5. If the problem is inner groove distortion, check whether your stylus is conical or elliptical.  An elliptical stylus is much better at tracking the curvature at the inner grooves and will sound MUCH cleaner than a conical.  It’s a fact.
6. Last, but not least if you are playing the record on a DJ turntable with a short, straight arm, it will not track worth a damn no matter what you do!  These were only designed to keep the stylus in the groove when scratching the record back and forth.  Their ability to track a record is non-existent.  Get a real turntable!!!