Tracking force ensures your stylus stays in the groove, cartridge alignment ensures it stays in the correct position. Because a tonearm moves in an arc across the record rather than a straight line, it is mathematically impossible for the stylus to be perfectly centered in the groove at every single point on the record. Alignment is the method of minimizing this "tracking error" so that your stylus is perfectly positioned in the groove to ensure proper audio reproduction.

Poor alignment is often the cause behind inner-groove distortion—that fuzzy, harsh sound you might suddenly hear toward the end of a record.

Why Use a Protractor?

A protractor is a template that provides a grid of lines corresponding to the correct geometry for your tonearm. By aligning your cartridge to these lines, you ensure that the stylus rides in the groove at the optimum angle, reducing distortion and protecting your records from uneven wear.

How to Align Your Cartridge:

1. Safety First: Install or lower the stylus guard if your cartridge has one with your tonearm secure in its rest. Loosen the two screws holding the cartridge to the headshell just enough so that you can nudge it, but not so loose that it’s flopping around.

2. Position the Protractor: Place your protractor on the platter. Unlock your tonearm and gently move the tonearm so the stylus tip rests on the inner grid point (null point).

3. Check Parallelism: Look at the body of the cartridge (or the cantilever, if you have a magnifying glass). The sides of the cartridge body should be perfectly parallel to the grid lines on the protractor.

4. Adjust: If the cartridge is angled to the left or right, gently nudge it until it aligns perfectly with the lines. You may need to move the cartridge slightly forward or backward in the headshell slots to get it into the right spot.

5. The Second Point: Once aligned on the inner grid, lift the tonearm, with your cueing lever if you have one, and move it to the outer grid point. If the cartridge aligns perfectly there without needing further adjustment at the inner point, you are set. If it doesn’t, repeat the process until it aligns at both points.

6. Secure: Once perfectly aligned at both points, carefully tighten the screws. Be gentle—you don’t want to strip the threads or knock the cartridge out of alignment while tightening.

7. One Final Check: Check your alignment one last time so ensure its still accurate.

Pro Tip: Patience with trial and error is rewarding here. Alignment can be frustrating for some because tightening the screws often shifts the cartridge slightly. If you don't have a physical protractor, you can easily find and print accurate ones online—just ensure you print them at 100% scale and verify the measurement with a ruler before use.