The cartridge of a turntable is an essential link in the chain that connects the record to your speakers. This element, however small, can drastically affect the sound. That’s why many vinyl enthusiasts use multiple cartridges, each mounted on a dedicated headhsell. This allows a flexibility to enjoy a more appropriate sound signature for certain musical styles or types of mixing, or simply to adjust the sound reproduction according to the mood of the moment. An advantage exclusive to vinyl turntables. Thanks to tonearms and headhsells adopting the universal SME mounting standard and the use of a digital scale, the switch can be done in under a minute. If you’ve ever had to change the cartridge of your turntable, whether to improve the sound or replace a worn-out model, you’ve probably been faced with the choice between a moving magnet cartridge and a moving coil or even a moving iron cartridge. So what is the difference between these technologies and why choose one type of cartridge over another?
Some cartridges are specially designed to read old pressings. This is the case of mono cartridges , developed for listening to monophonic records. Stereo sound started being used towards the end of the 1950s and did not experience real commercial success until the mid-1960s. Mono vinyl records released between the 1950s and 1960s should therefore ideally be read with a mono cartridge, the latter being designed to extract all the information engraved in the groove as well as possible.
The 78 rpm cartridges are also designed for vintage records. Made of shellac, a material more fragile than vinyl, 78 rpm records feature a wider groove than that of a standard vinyl record. The use of a cartridge designed for vinyl records would therefore seriously damage the groove of the 78 rpm record and the sound would be far from satisfactory. A 78 rpm cartridge and a vinyl turntable offering this playback option are two essential elements for listening to vintage 78 rpm records.
Moving magnet cartridge and moving coil cartridge: what are the differences?
Moving Magnet (MM) and Moving Coil (MC) cartridges both function as tiny electromagnetic generators. They convert the mechanical movement (vibration) created by the stylus (association of diamond and cantilever) which moves in the groove of a disc into an electrical signal. The latter will be amplified and processed by an RIAA phono preamp so that we can listen to it. Both cartridge types use a combination of magnets and wire coils to generate the signal, either vibrating in unison with the stylus assembly to which they are attached.
Navigating the groove of a record is no easy task. The amplitude of the signal varies enormously, which requires a generator capable of reacting very quickly to the dips and bumps, while accurately following the groove. To accomplish this task, the stylus must be both light and robust. It must be light to respond quickly and limit disc wear, and rigid to quickly and accurately transmit vibrations from the stylus tip to the generator. The set must have very little resonance, and any resonance must not only be kept outside the audible frequency band (20 to 20,000 Hz) so as not to affect the quality of the sound it produces, but also be low enough in frequency not to accentuate the noise of vibrations and resonances.
Moving magnet cartridges
A moving magnet cartridge (MM stands for Moving Magnet) performs the energy conversion by connecting the vibrating cantilever to a magnet which in turn vibrates near a pair of coils. The small magnet (placed between the two coils) vibrates and, in doing so, produces an electric current of low intensity.
Moving magnet cartridges are robust and produce a moderate to high output level. In addition, their diamond tip can be replaced or even upgraded, as is the case with Ortofon cartridges from the 2M range for example. They are also generally compatible with all hi-fi stereo amplifiers equipped with a phono input as well as with all phono preamps .
The moving parts of MM cartridge are however heavier than on the moving coil models. MM cartridges can therefore be a bit less accurate when it comes to reading subtle changes in the groove, especially at high frequencies. There are, however, high-end moving magnet cartridges capable of competing with, or even surpassing, moving coil models.
Moving coil cartridges
A moving coil (MC) cartridge uses an inverted design compared to that of a moving magnet model. The cantilever therefore vibrates a coil near fixed magnets. The coil is attached to the cantilever and moves within the field of the fixed permanent magnets to generate the electrical signal. The coil is much smaller than those used in a moving magnet design.
Thanks to their low mass, moving coil cartridges offer better tracking of the groove, which results in a wider frequency response, as well as better transients in the high frequencies and a more detailed reproduction of the original signal. However, the manufacture of a moving coil cartridge is more expensive, which is reflected in the price of the cartridge. The output signal is much weaker and requires a phono preamp with an additional gain stage.
Using a preamp compatible with moving magnet and moving coil cartridges offers more versatility and ensures a more durable installation. Moving coil cartridges are also more delicate than moving magnet models and their stylus generally cannot be replaced by the user.
| Advantages | Disadvantages | |
| Moving magnet | Affordable Replaceable stylus Compatible with all preamps | Heavier Less accurate high frequencies |
| Moving coil | Lighter mobile parts Better tracking High frequencies more precise | Stylus cannot be replaced Restricted compatibility |
What is a moving iron cartridge?
Une cellule à ferrite mobile (MI pour Moving Iron) fonctionne d’une manière très similaire à une conception à aimant mobile, à ceci près que l’aimant est remplacé par un alliage magnétique. Cela présente l’avantage d’obtenir des pièces mobiles plus légères et plus précises. On retrouve cette technologie principalement avec les cellules Grado qui a fait des cellules à ferrite mobile sa spécialité. Les cellules à ferrite mobile ont une sortie relativement élevée et nécessitent une impédance de charge de 47 kΩ pour que le courant circule, ce qui les rend compatibles avec l’entrée phono MM que l’on trouve sur de nombreux amplificateurs intégrés.
