Careful alignment of your phono cartridge using one of the alignment protractors offered below will allow you to minimize the tracking deviations and thereby keep the harmonic distortion below the hearing threshold.
When a phonograph record is created the grooves are initially cut by a cutting lathe. During this process the cutting head is always perfectly tangential to the record-to-be that is slowly spun below it. Whenever we play a vinyl record on our turntable the goal is to retrace the movements of the cutting head as precisely as possible. On turntables with pivotal tonearms (i.e., most turntables) it is not possible to succeed 100% at this and the ensuing deviations cause harmonic distortion. When the cartridge is aligned using a protractor this distortion is minimized.