How to Align a Turntable Cartridge

A well-aligned cartridge sounds calm. Voices stand clearly between the speakers, sibilants stay clean, and the last track on a side sounds as composed as the first. Getting there takes about fifteen minutes and a good protractor. This guide explains what alignment means and walks you through it step by step.

Why alignment matters

When a record is cut, the cutting head travels across the lacquer in a straight line from the edge towards the center. A pivoted tonearm cannot do that. It swings in an arc, so the stylus meets the groove at a slightly different angle at almost every point of the side. This angle is called tracking error.

Tracking error cannot be removed entirely, but it can be kept small. A misaligned cartridge reads the two groove walls unevenly. You hear it as harsh sibilants, a less stable stereo image and more distortion towards the end of a side. Stylus and record also wear less evenly.

Overhang, offset angle and null points

Alignment comes down to two settings:

• Overhang: how far the stylus reaches past the center of the spindle. You set it by sliding the cartridge forward or back in the headshell.
• Offset angle: the angle at which the cartridge sits in the headshell. You set it by turning the cartridge slightly.

Set correctly, the stylus sits exactly in line with the groove at two points on the record. These are the null points. Between and around them the error stays small. A two-point protractor shows both null points, so you can check overhang and offset without knowing your tonearm's exact dimensions.

Why the geometry makes a difference

Where the null points sit is a matter of geometry. Established geometries differ mainly in how they balance the error between outer and inner grooves. Many of them calculate with grooves that run almost to the label.

On most records the music ends earlier. The Achat 1 therefore uses its own OTA® geometry (Optimum Tracking Angle), developed specifically for LPs, with null points further out, at 74 and 128 mm. The largest tracking error stays at around 1.2 degrees, compared with up to 2.1 degrees for a DIN alignment (calculated for a mounting distance of 211 mm). Distortion caused by tracking error drops by up to 80 % compared with DIN-oriented protractors. The error is spread more evenly across the area where the music actually is, so a side sounds settled from the first track to the last.

The OTA geometry needs about 3 to 4 mm more overhang than a DIN alignment. Your cartridge must be able to slide that much further forward in the headshell. If it cannot, the tonearm pivot has to move closer to the center of the platter.

What you need

• A two-point protractor, such as the Achat 1 cartridge alignment protractor
• A mechanical pencil lead and a little adhesive tape as a reading aid
• A small screwdriver or hex key for the cartridge screws
• Good light and, if possible, a magnifier
• Your usual platter mat on the platter, since it changes the height at which the protractor sits

How to align a turntable cartridge, step by step

1. Prepare the turntable. Level the turntable, place the mat you play with on the platter and set the tracking force roughly to the cartridge manufacturer's value. Keep the motor switched off during the entire alignment. Loosen the cartridge screws just enough that the cartridge moves with light pressure.

2. Attach a reading aid. Tape a mechanical pencil lead to the front or underside of the cartridge, level and at a right angle to the cantilever. The lead extends the edge of the cartridge, so you can see much more precisely whether it runs parallel to the guide lines.

3. Place the protractor. Put it over the spindle like a record so it lies flat. Keep the stylus guard on while you move the arm by hand and remove it only to lower the stylus.

4. Inner null point (R74). Swing the tonearm over the protractor until the stylus tip is above the inner null point R74. Keep the arm raised. Turn the cartridge in the headshell until the pencil lead runs parallel to the guide lines. Then lower the stylus gently onto the null point to check the result.

5. Outer null point (R128). Lift the stylus and lower it onto the arc line of R128. Now turn the protractor carefully so the stylus moves towards the null point. If the lead is already parallel to the guide lines before the stylus reaches the null point, the overhang is too small: slide the cartridge slightly forward.

6. Go back and forth. Each correction at one point changes the other a little. Realign the cartridge or adjust the overhang until the lead and the guide lines run parallel at both null points. Two or three rounds are usual.

7. Tighten and check. Tighten the screws evenly, a little at a time, so the cartridge does not twist. Then check both null points one last time and remove the lead.

Work gently, the cantilever is delicate. Always lower the stylus slowly and turn the protractor with a light hand.

After the alignment

The protractor sets overhang and offset angle. Four further settings complete the setup and are made with other tools:

• Tracking force: set precisely to the cartridge manufacturer's value with a stylus gauge.
• Anti-skating: as a starting point, the same value as the tracking force.
• Arm height (VTA): so the tonearm runs roughly parallel to the record with the stylus lowered.
• Azimuth: so the stylus stands upright in the groove when seen from the front.

Printed template or precision protractor?

Printable paper protractors are freely available and a reasonable place to start. Their limits are practical. A printer rarely scales to the exact millimeter, paper bends and shifts, and the center hole sits loosely on the spindle. A small error at the spindle becomes a larger one at the null points.

A protractor made of anodized aluminum stays flat and dimensionally stable, fits the spindle snugly and gives the same result at every cartridge change. That is what the Achat 1 was made for: handmade in Germany, with its null points marked R74 and R128 and parallel guide lines at both. Discover the Achat 1 turntable cartridge alignment protractor.

Frequently asked questions

How do I know if my cartridge is misaligned?
Typical signs are harsh sibilants, a stereo image that leans to one side and distortion that grows towards the end of a side. If you notice these, checking the alignment is a good first step.

Does a two-point protractor work with every tonearm?
It works with nearly all pivoted tonearms, because it checks the result at the null points rather than relying on the arm's dimensions. For the OTA geometry, the cartridge must be able to slide about 3 to 4 mm further forward than with DIN. Linear tracking arms follow the groove in a straight line and need no protractor of this kind.

How often should I check the alignment?
At every cartridge change, after moving or transporting the turntable, and occasionally in between. With a protractor at hand it takes a few minutes.

Which geometry should I choose?
There is no single right answer. Each geometry places its null points according to where it considers the error most important. The OTA geometry of the Achat 1 concentrates on the area of the record where the music is.

More for your turntable: Turntable accessories and the Perfect Interface turntable mat.