Hi-Fi News & Record Review Cartridge Alignment Protractor. In addition to being highly collectable as a nice piece of audio history, these are very accurate plastic laminated two point protractors, which come complete with very comprehensive instructions. They are suitable for all tonearms. In case anyone does not know this already, if your cartridge is even a fraction out of alignment the sound quality will be substantially degraded, and it will also damage your records. Using this protractor will allow you to align your cartridge perfectly - Go on, treat your turntable!