Unlike current protractor designs this protractor does not depend on one's eyesight to make adjustments and unlike current designs this protractor safely protects the stylus during adjustment.

Current protractors depend on aligning the phono cartridge to a printed grid pattern with the stylus placed on the grid. Alignment is subject to discrepancy when the shape of a cartridge body does not conform to the printed grid pattern and errors with unreliable line sight alignment. Also the stylus is unprotected from damage.

Current protractor designs were created when stylus shapes were much simpler and inaccurate alignment more tolerable. Newer stylus shapes require very accurate alignment to work at their full potential.

The Grimm’s protractor utilizes confinement of the phono cartridge body to insure accurate tangency and overhang of the stylus at the calculated null points of the tonearm's arc. Accurate tangency and overhang adjustments are not subject to line of sight errors and the stylus stays protected during adjustment. The protractor can also be used to check azimuth (cartridge physically neutral)...

How to Use

The cartridge is loosely mounted onto the tonearm WITHOUT the stylus and the cartridge placed into the protractor. Adjust the cartridge at tonearm so that one of the spindle holes of the protractor can be placed over the turntable spindle. If needed, adjust cartridge so the other protractor spindle hole fits over the turntable spindle. Adjustment is complete when the cartridge requires no adjustment to fit both spindle holes over the spindle.