In This Series
- 1 How Do Vinyl Records Work?
- 2 Components
- 2.1 The Platter
- 2.2 The Bearing
- 2.3 The Motor
- 2.4 The Tonearm
- 2.5 The Cartridge
- 3 Phono Stages
- 4 Should You Buy an All-In-1 Turntable?
- 5 The Current Market
- 6 How to Setup a Turntable
- 7 How to Install and Align a Turntable Cartridge
- 8 Optimising The Sound
- 9 Purchasing a Used Turntable
- 10 Turntable, Tonearm and Cartridge Specifications
- 10.1 Tonearm Specifications
- 10.2 Turntable Specifications
- 10.3 Cartridge Specifications
- 11 Turntable Drive Systems
- 12 Recommended Tools
- 13 Free Protractors and Strobe Discs
- 14 Conclusions
If you’ve purchased a turntable without a factory-fitted cartridge, or you’re upgrading the cartridge of your current model, you’ll need to install a cartridge yourself. This can seem like a daunting task, however it’s not particularly difficult with plenty of spare time, a steady hand and the absence of distraction.
Packaged with your cartridge you’ll usually receive a set of mounting hardware, including screws (usually of a couple of different lengths), a pair of mounting nuts, and often a pair of tiny washers and a screwdriver. Some cartridges will include a brush, used to remove dust from the stylus, and some are supplied with a set of small wires to connect the cartridge to a universal headshell. Some cartridges feature threaded mounting holes removing the need for the nuts and making installation that little bit easier.
The first step is to connect the leads of the cartridge to the 4 pins on its rear side. These are colour coded, with a diagram usually provided in the documentation to show you which way round they go. Align the cartridge tags with the pins of the cartridge and press them onto the pins in a straight line, taking care not to bend the tags (which are particularly delicate) or the pins themselves. You’ll also want to take care when arranging the wires so that they do not exert too much pressure on the back of the cartridge during alignment.
Once wired up, you can mount the cartridge to the headshell using the provided mounting hardware. You may find it easier to mount the cartridge to the headshell as below before connecting the wires, particularly if your cartridge doesn’t provide a cover for the fragile stylus. However some headshells don’t offer enough clearance between the end of the arm tube and the rear of the cartridge to connect the wires.
I usually prefer to mount the screws on the top, with a washer separating the head of the screw and the slot of the headshell. This prevents scratching, and makes the cartridge easier to manoeuvre. The nuts then mount beneath the cartridge body, the screws passing through the sides of the body to secure the cartridge in place. It’s also possible to mount the screws up-side-down too, and this may be necessary if the length of the screws is such that they interfere with any protrusions on the side of the cartridge body.
A modern microgroove record is named as such because the grooves are quite literally microscopic. The width of a record groove ranges from 0.025MM to 0.035MM, smaller than a human hair which measures at 0.17MM – 0.181MM. A stylus exerts tremendous force on the walls of a record groove, a seemingly insignificant tracking force of 1.5 grams yielding about 340 pounds per square inch of force when translated to the tiny contact area of the stylus.
When you consider these numbers, the relation of stylus to groove is of great importance. The stylus must be aligned such that it can accurately track the record groove. An incorrectly aligned stylus can yield poor sound quality and asymmetrical record and stylus wear.
As the stylus traces the record, it should remain tangential to the record groove. However with a pivotal or radial arm there are only 2 points on a record where the stylus is tangential to the groove, known as the null points. A number of mathematicians over the years have offered theories as to where these null points should be, beginning with Lofgren in 1938 and later Stevenson in the 1980s. Their calculated alignments differ slightly and are based on the inner and outer groove radii of a vinyl record, 2 points on the record at a specified distance from the centre spindle.
Adjusting the overhang and Zenith angle of the cartridge will require an alignment protractor, unless you’re using a Rega cartridge and tonearm. Rega cartridges with the exception of the Bias2 and Carbon models feature a 3rd mounting hole, which aligns with a corresponding hole on the front of the tonearm headshell. The nuts provided with Rega cartridges are designed to fit exactly into the headshell slots, necessitating that the 2 screws at either side be installed from beneath. When installed, and the 3rd mounting screw is installed, the cartridge is aligned and you can set your tracking force and anti-skate as above.
For everyone else there are hundreds of protractors available on the market. They range from cheap laser-engraved plastic templates to astronomically expensive alignment gauges running into the many hundreds of pounds. It’s also possible to calculate your own using some computer software and a printer capable of printing an image accurately to scale. Freely downloadable protractors are also available to be printed in the same fashion. I have provided a selection of protractors in the Free Protrectors and Strobe Discs section.
Protractors come in a couple of forms. The simplest protractors offer a point on which the stylus tip is placed, and a grid of parallel lines to which the cartridge can be aligned. Some protractors offer a pair of grids useful for checking the position of the cartridge at both null points.
By far the most accurate protractor is the arc protractor. This protractor consists of an arc line following the arc that the stylus will trace across the record, and a grid to which the cartridge can be aligned. The position of the cartridge is adjusted in the headshell until the stylus can follow the arc of the protractor, at which point the cartridge is aligned to the provided grid to set the Zenith angle. Arc protractors are based not only on the inner and outer groove radii of the record but also the pivot to spindle distance. The accuracy of an arc protractor depends heavily on the distance between the centre of the turntable’s spindle and the pivot point of the arm being accurate.
Some turntables, mostly DJ turntables with universal head shells are provided with an alignment gauge, removing the need for a protractor. With the cartridge mounted to the headshell and the headshell installed into the gauge, you simply align the tip of the stylus with the end of the gauge and angle the cartridge body so that it is parallel to the straight side of the headshell. A similar alignment can be set by adjusting the cartridge such that the body of the cartridge is parallel to the headshell and the distance between the stylus tip and the rubber washer at the rear of the headshell is exactly 52MM.
These methods will get you close to the perfect alignment, though the manufacturing accuracy of the gauge or ruler, not to mention the difficulty in seeing the tiny stylus tip with the naked eye are all variables that will affect your accuracy when aligning with these methods. Such gauges are only provided with those turntables with detachable head shells, and not all will include such a device anyway.
Fortunately with a little time, patience and extreme care, aligning a cartridge with a protractor isn’t a particularly difficult task. To get started, mount the cartridge to the tonearm using the provided mounting hardware, positioning the cartridge such that the mounting screws are roughly in the middle of the cartridge slots. Tighten the cartridge so that it can move but will not shift as you move the arm or due to the pressure of the wires behind.
Next roughly set the vertical tracking force as described Here. This is an often overlooked and essential step, as failure to add some counterbalance to the arm during cartridge alignment will result in the full weight of the cartridge and tonearm being placed on the stylus cantilever, crushing it and damaging the cartridge suspension.
In the next step we’ll assume that you’re using an arc protractor. If not, your protractor will undoubtedly have been provided with some instructions for use, which you should follow carefully to achieve optimal alignment.
With the tracking force set, but the anti-skate left at zero, set the stylus on the alignment protractor. Move the cartridge body in the headshell until the tip of the stylus will land anywhere on the arc line of the protractor when the needle is lowered to the protractor using your arm lifter. Never drag the stylus on the protractor itself, as doing so will likely result in instantaneous damage to the stylus.
Once the stylus tip is precisely tracing the arc, move the stylus over the grid and align the cartridge so that the body aligns with the parallel lines on the grid. Once aligned, ensure that the stylus is still able to follow the arc and tighten the cartridge in the headshell, checking your work once more to ensure that nothing has shifted. Once done, re-balance the tonearm and reset the tracking force, apply some anti-skate and play your first record. It’s that simple.
A note concerning the Zenith angle. Many choose to align the stylus cantilever itself and do not recommend aligning the cartridge body. This is because some cartridges are manufactured such that their cantilevers are not exactly perpendicular to their body. However aligning the body is a sufficient solution, as the record groove will pull the cantilever into alignment. A good analogy is that of a car toeing a caravan down a track, the caravan being attached via a single pivot. If the car travels in a straight line, at speed, the caravan will naturally follow the line of the car. The cartridge body is the same. As the arm with the cartridge body attached traces the arc of the groove, the cantilever will naturally follow and be pulled into alignment by the body of the cartridge.
Also many arms do not allow you to completely zero the anti-skate. Even with the anti-skate set to zero a slight amount of bias force is always exerted on the arm, pulling it back toward its rest. As a stationary protractor offers no centripetal force to counteract this slight offset, this offset may cause the cantilever to deflect slightly when sitting on the protractor resulting in an inaccurate alignment should you attempt to align the cantilever to the grid.
This article is part of our Guide to Turntables and Vinyl series. Continue reading: Part 8, How To Optimise a Turntable for the Best Sound Quality.