カートリッジの交換ガイド

Do you wanna change a cartridge? (Apologies for the Frozen reference but if you can't use it here, when can you?)

We've covered in the past that the lifespan of a stylus is finite and that sooner or later it will wear out and need replacement. If you have a moving magnet type cartridge, you can simply keep the body of the cartridge bolted to the arm and change the stylus assembly. This is quick, pretty simple and takes about five minutes to do.

If you've worn the stylus out, you might take the opportunity to change the whole cartridge rather than the stylus. At this point, things get a little more serious. Changing a cartridge is rather more delicate that changing a stylus and depending on the arm and cartridge combination you are looking to create, the task can vary from 'a bit fiddly' to the sort of process that Dante would have the inmates of a circle of hell performing.

This blog piece does not have all the answers—not least because I discovered during the photography for it that many parts of the process can't really be shot as they happen because it simply isn't possible to do both or even get out of the way of the camera satisfactorily for someone else to shoot it. What it will try and do is cover the basics and lay out some dos and don'ts. Like everything to do with vinyl, the process is as varied as the hardware and your own ability will vary as well. I worked with a guy who could install a cartridge in under five minutes and be so close to the factory alignment, there was no point trying to better it. Sadly, we are not all like him.

What are my options?

Firstly, there are two major types of tonearm and two major types of cartridge and their attributes may influence the type of cartridge you choose to buy. Arms with a detachable headshell are easier to work on in these cases. The entire end of the arm is on a locked plug type fitting and this can be removed and the headshell worked on at pretty much whatever angle takes your fancy. In these cases, it is relatively simple to attach a cartridge with either a threaded body or fastenings.

Arms that have a one piece tube are a little different in this regard. You will need to work in situ and this will likely steer you towards cartridges that have a threaded body. What does 'threaded body' mean? Simply that the cartridge body is part of its own fastening. The mounting bolt screws directly into the cartridge and pulls it into place on the arm. With a one piece arm this means that the cartridge is an order of magnitude easier to attach to the arm because you aren't struggling to get a fixing bolt into place while lining everything up. There is a cheat to this which we'll come to in due course.

What do I need?

For a hassle-free swap, you need the following items:

• A screwdriver or Allen key depending on the bolt that the cartridge manufacturer has chosen to supply it with.


• A pair of tweezers


• A stylus force gauge


• An alignment protractor


• At least thirty minutes of free time and preferably a little more to be on the safe side.  

How do I do it?

Working on the principle that you are first removing the old cartridge, the first thing to do is disconnect the arm leads from the pins on the cartridge. I always recommend using tweezers to do this. Many arms have good strong wires and tags which you can remove by hand but it is good practice—as well as being much easier- to use tweezers to remove them. Always grip the tags themselves in order not to rip the cable out of the tag.

Having done this, you can unscrew the cartridge. If the cartridge is unthreaded, gently apply little pressure to the nut securing the bolt and unscrew the bolt. With unthreaded cartridges, you can generally release one bolt then the other without a problem. With threaded cartridges, you don't need to hold the bolt but it is more important to unscrew the bolts a little bit at a time as it reduces the chances of cross threading. With that, the old cartridge is gone and you can look to fit the new one.

First things first, keep the stylus guard on. While you are manhandling the cartridge, you'll want to keep that delicate stylus safe. If you have a detachable headshell arm, you can effectively do what you have just done to remove the cartridge in reverse. One very important thing to do it check the wiring of the pins on the new cartridge as it is not a given it is the same as the old one. Don't screw the cartridge tight to the headshell as you will need to be able to move it to align it.

With a fixed headshell arm, the easiest thing you can do is remove the counterweight off the back. This will mean that the arm drops forward and you can work over the platter to line the cartridge up and screw it in. With a threaded body cartridge you can then screw it into semi tightness and reapply the cartridge tags with your tweezers. If you are attaching an unthreaded cartridge to an arm with a fixed headshell, it makes sense to invert the bolts so you can more easily attach the nuts that keep the cartridge in place. Having done this, you can then replace the counterweight and get the arm rebalanced.

What then?

Once the cartridge is physically on the arm, you need to get it lined up. Each turntable will have differing alignment requirements but protractors for pretty much everything are available online. Get the cartridge over the alignment point, line it up as perfectly as you can and once you are happy, you can then screw the cartridge firmly into its permanent location. Don't tighten the bolts to within an inch of their lives, simply enough to ensure that the cartridge doesn't move about.

With this done, you can set the tracking force. Using the stylus force gauge, you can get the required weights set by moving the counterweight at the back of the arm. It is worth noting that many cartridges are supplied with a high and low figure- a boundary rather than an exact weight to set to. In these cases, it is usually best to set it in the middle and experiment if you are feeling brave.

Once done, if your arm allows for it, you can set the vertical tracking angle. In a perfect world, once the arm has been lowered onto the record, it should be level from front to back. This measurement is the vertical tracking angle—often shortened to VTA—and on many arms can be adjusted by means of a collar on the arm itself or in some cases- notably Rega- a spacer physically added to the arm base.

Altering the angle that the stylus hits the record will once again affect the bass and treble depending on whether the arm is tail up or tail down. The amount of adjustment that an arm will allow for does vary so if you are matching an arm and a cartridge, do check the size of the cart and make sure you can get the necessary elevation on the arm. If the arm has no adjustment, you will need to choose a cartridge that naturally allows for a level VTA.

With all of these steps completed to your satisfaction, the new cartridge is ready to go. Remember that it will generally need a few hours of playing to sound its best and that it can be worth checking after a few days to see if anything has shifted. Changing a cartridge should never be taken lightly. If you rush it or don't give it your full attention, it is very easy to break things but the results of a good cartridge upgrade will make the stress seem well worthwhile.