Hi, hope to open up a discussion on cartridge alignment and use of protractors out there in the market. While my own tonearm has only a ruler supplied by ET to align itself, I have a Dennesen Soundtracker which I use to help my friends align their pivoted arm. An opening question would be 'Would different protractors register different null points?' Or to put it in a another way, suppose I have set a null point based on the Dennesen protractor, should or would the null point be different if I counter check it with say, a Feikert proctractor or other protractors?