Needless to say, a record is a dirt magnet. The record can’t help it -- attracting dirt is part of its DNA. Dibasic lead stearate or cadmium or other esters of stearic acid make up as much as 2 percent of the vinyl compound. These additives provide thermal buffering for the vinyl during pressing, aid the platter’s release from the mold and prevent oxidation on the newly minted record. Function served, mold-release agents turn into foreign substances between stylus and groove, where they remain and attract dirt. Chemical analyses of 50-year-old used records reveals mold-release agent still in the groove.
Playing dirty records not only generates audible clicks
and pops, it wreaks physical havoc. When a stylus exerting N tons of pressure per
square inch smacks head on into a family of 5-micron-sized rocks sailing along at 60
knots, the impact can deform the groove wall or, thanks to heat generated by the forces in
play, fuse those rocks to the vinyl itself.
I always clean new records before playing them.