"P" mount cartridges are GREAT for DJs since they don't have to be realigned when changing cartridge bodies. (Just take the old one out and put the new one in.) However tangential tracking is something that must be looked at and is impossible to change with a SL-1200 and a "P" mount cartridge and I would refer you to the Vinyl Engine for a good protractor to see how close you are with the cartridge and the tone arm.
Cartridge Alignment Protractors | Free Turntable, Tonearm & Cartridge Tools | Vinyl Engine. Also the arm should be parallel to the surface of the record which is something that also should be checked and adjusted.
Vinyl engine also has a lot of good suggestions for setting up turntables plus you may want to look at this site
Phono CARTRIDGE Mounting, TONEARM Alignment TOOL, TURNTABLE Set-Up, VTA, LTA, Adjustment of BIAS Compensation. which also has a lot of good suggestions for setting up a turntable and or cartridge/
Best of luck and good listening.
__________________
-TOM-
Thomas W. Bethel
Managing Director
Acoustik Musik, Ltd.
Room with a View Productions
Oberlin, OH 44074
www.acoustikmusik.com
Doing what you love is freedom.
Loving what you do is happiness.