How to Align a Turntable Cartridge With a Protractor
If you've just mounted a new cartridge, setting tracking force isn't the end of the job. The cartridge also has to sit in the right position and at the right angle in the headshell, or the stylus will meet the groove slightly sideways for much of the record. That's what an alignment protractor is for.
It sounds technical, but the actual task is slow, careful nudging of two screws until a pair of lines match up. This guide explains what you're adjusting, the main protractor types, and a step-by-step process that works on most pivoted tonearms.
- A protractor sets overhang (how far forward the cartridge sits) and offset angle (which way it points).
- With a two-point protractor, you adjust until the cantilever lines up with the grid at both null points.
- Set tracking force first, keep the stylus guard handy, and work with the platter still.
- If your deck came with the cartridge pre-mounted and you haven't touched it, you probably don't need to align it.
Why alignment matters
Records are cut by a cutting head that moves in a straight line across the disc. Most home turntables use a pivoted tonearm, which swings in an arc instead. Because of that geometry, a pivoted arm can only be perfectly tangent to the groove at two points across the record, called the null points. Everywhere else, there's a small error.
Alignment chooses where those two null points fall and keeps the error between them small. A poorly aligned cartridge can produce more distortion, especially toward the inner grooves, uneven channel balance, and uneven stylus wear.
The terms you'll see
Overhang
How far the stylus tip extends past the center spindle when the arm is swung over it. Set by sliding the cartridge forward or back in the headshell slots.
Offset angle
The angle the cartridge is twisted in the headshell relative to the arm. Set by rotating the cartridge slightly.
Null points
The two radii where the stylus is exactly tangent to the groove. Different alignment schemes put them in different places.
Effective length
Distance from the arm pivot to the stylus tip. Arc protractors and some calculations use it.
You'll also see names like Baerwald (sometimes called Löfgren A), Löfgren B and Stevenson. These are alignment geometries that place the null points differently to spread distortion across the record in different ways. Baerwald is a common, well-balanced default for most listeners. Stevenson favors the inner grooves. If your protractor offers a choice and you don't have a reason to pick otherwise, Baerwald is a reasonable starting point.
Protractor types
| Type | How it works | Good for |
|---|---|---|
| Printable two-point (paper) | Printed grid that fits over the spindle, with two null-point grids | Trying alignment at no cost; print at exactly 100% scale |
| Two-point mirrored (acrylic or card) | Same idea, with a mirror surface to help sight the cantilever and its reflection | Most home users; more precise viewing |
| Arc protractor | Draws the stylus arc for a specific effective length | Users who know their arm's specs and want to check geometry |
| Manufacturer-specific jig | A gauge made for a specific tonearm or headshell | Owners of that arm; often the simplest option |
A mirrored two-point protractor is the sweet spot for most people. If you print a paper version, check the scale with a ruler against a reference mark on the sheet before trusting it. Printer scaling is the most common source of error.
What you need
- A protractor (two-point or one made for your arm).
- A small screwdriver that fits the cartridge screws. Some cartridges use hex screws.
- Good light, and a magnifier or phone camera zoom helps a lot.
- A stylus force gauge or a calibrated counterweight, since you should set force before aligning.
- Patience. Plan for 20 to 40 minutes the first time.
Step-by-step: two-point alignment
- Mount the cartridge loosely. Screws snug enough that the cartridge stays put but can still slide and rotate with a gentle push. Connect the four tonearm wires to the matching colored pins if you haven't already.
- Balance the arm and set tracking force to the cartridge maker's recommendation. Force affects how the stylus sits, so do it first.
- Place the protractor on the spindle, flat on the mat. Leave the platter stopped and the motor off.
- Lower the stylus onto the outer null point (the small dot or cross on the grid nearer the edge). Use the cueing lever and adjust the protractor's rotation so the stylus lands exactly on the dot.
- Check the cantilever against the grid lines. Looking straight down, the cantilever (not the cartridge body) should be parallel to the grid lines.
- Move to the inner null point. Lift, rotate the protractor, and lower the stylus onto the inner dot. Check parallel again.
- Adjust. If it's twisted the same way at both points, rotate the cartridge (offset). If it's twisted opposite ways at the two points, slide the cartridge forward or back (overhang). Small moves only.
- Repeat outer, inner, adjust, until it's parallel at both points.
- Tighten evenly, alternating screws a little at a time so the cartridge doesn't twist as you tighten. Recheck both null points afterward.
- Recheck tracking force and anti-skate. See our tracking force and anti-skate guide.
Beyond overhang: azimuth and VTA
Two more adjustments exist on some arms. Treat them as optional fine-tuning.
Azimuth
Viewed from the front, the stylus should stand straight up, not tilted left or right. Some headshells or arms let you rotate to correct it; many don't. A visual check with a small mirror under the stylus is a reasonable start.
VTA / SRA (arm height)
Vertical tracking angle relates to arm height. A common starting point is to adjust arm height so the tonearm is roughly parallel to the record when the stylus is down. Many entry-level decks have no height adjustment, and that's fine.
Common mistakes
| Mistake | Result | Avoid it by |
|---|---|---|
| Paper protractor printed at the wrong scale | Every measurement is off | Check the printed scale reference with a ruler |
| Aligning the cartridge body instead of the cantilever | Stylus still misaligned | Sight along the cantilever from above |
| Tightening one screw fully, then the other | Cartridge twists | Tighten alternately in small steps |
| Over-tightening | Stripped threads or cracked body | Firm, not forced |
| Swinging the arm onto the protractor fast | Bent cantilever | Always use the cue lever, move slowly |
| Forgetting force afterward | Force changes slightly after remounting | Recheck with a gauge |
When you don't need to align
- Pre-mounted cartridges on new decks are usually aligned at the factory. If you haven't changed or moved the cartridge, leave it alone.
- P-mount (T4P) cartridges plug into a fixed position, so alignment isn't adjustable. See half-inch vs P-mount.
- Replacing only the stylus on the same cartridge body doesn't usually require realignment. Just check that the new stylus is seated fully.
How to tell if alignment is off
Alignment errors don't usually cause dramatic symptoms. Listen for these more subtle signs, especially after a cartridge change:
- Sibilance (harsh "s" and "t" sounds) or distortion that gets worse toward the end of a side.
- Noticeably different distortion between left and right channels.
- A cartridge that visibly sits crooked in the headshell when viewed from above.
- Uneven wear on a stylus you've had checked under magnification.
Any of these can have other causes, including worn records, a worn stylus or wrong anti-skate, so check those too. But if you've never aligned a cartridge you installed yourself, alignment is the first place to look.
Frequently asked questions
Do I need a protractor if my turntable came with the cartridge installed?
Usually not. Pre-mounted cartridges are typically aligned at the factory. You need a protractor when you install or move a cartridge.
Which alignment should I choose: Baerwald, Lofgren B or Stevenson?
Baerwald is a common, balanced default for most listeners. Lofgren B and Stevenson place the null points differently, trading lower distortion in one area of the record for more elsewhere.
Can I use a free printable protractor?
Yes, as long as it prints at exactly 100% scale. Check it against the scale reference printed on the sheet with a ruler before you rely on it.
Does replacing the stylus mean I have to realign?
Generally no, if you're replacing only the stylus on the same cartridge body and haven't moved the body. Make sure the new stylus is fully seated.
Should I align before or after setting tracking force?
Set tracking force first, then align, then recheck force and anti-skate after you've tightened the cartridge.
The bottom line
Alignment is a patience job, not a skill job. Set force first, use a protractor at the correct scale, sight along the cantilever at both null points, make small moves, and tighten evenly. Do it once after any cartridge change and you can forget about it until the next one. If you're still choosing a cartridge, our moving magnet vs moving coil guide is a good place to start.