Vinyl records have made a comeback in recent years, and with that comes the need for quality turntable equipment.
One essential component of a turntable is the phono cartridge, which reads the grooves on a record and turns them into audio signals.
There are many types of phono cartridges available, but one of the most common is the moving magnet (MM) cartridge.
In this article, we’ll take a closer look at what a moving magnet phono cartridge is, how it works, and its pros and cons.
Whether you’re a seasoned audiophile or just starting to explore the world of vinyl, understanding the basics of phono cartridges is essential to getting the most out of your turntable setup.
So let’s dive in and explore the world of moving magnet phono cartridges!
What Is A Moving Magnet Phono Cartridge
A moving magnet phono cartridge is a type of electromechanical transducer that is used to play vinyl records on a turntable. The cartridge contains a stylus, which is usually tipped with a gemstone like diamond or sapphire, that makes physical contact with the record’s groove.
As the stylus tracks the serrated groove, it vibrates a cantilever on which is mounted a permanent magnet that moves between the magnetic fields of sets of electromagnetic coils in the cartridge. The shifting magnetic fields generate an electrical current in the coils, which is then amplified and converted into sound by a loudspeaker.
What Is A Phono Cartridge?
A phono cartridge is a small electro-mechanical component that is mounted at the front of a tonearm on a turntable. It consists of two main sections: the cartridge body and the stylus assembly. The cartridge body houses the wire coils that generate the electrical signals, which are then transferred via the tonearm wires to the phono stage in the amplifier. On the other hand, the stylus assembly consists of a plastic molding with a cantilever or tube and a stylus or needle that vibrates as it traces the record grooves.
The stylus is the needle-shaped tip of diamond at the front end of the cantilever. It is responsible for making direct contact with the record’s groove and reading its modulations. The performance potential of a record playing system is defined by the capabilities of the phono cartridge.
Tonal balance, response range, clarity on musical peaks, stereo separation and imaging, and freedom from noise and distortion are all affected at the outset. Therefore, selecting this first component is critical to fully enjoying the rest of your system. Most cartridges are designed with a stylus assembly that is end-user replaceable, which means that you can upgrade to a higher quality stylus for improved sound quality.
The Basics Of A Moving Magnet Phono Cartridge
A moving magnet (MM) phono cartridge works by connecting the vibrating cantilever to a set of magnets that vibrate in close proximity to a pair of coiled wires. The tiny magnets, positioned between the two coils, vibrate and produce a small electrical current. This current is sent down the tonearm wires, out the turntable, and over to the phono preamp (or phono input of your amp/receiver) for proper amplification and equalization.
One of the main advantages of moving magnet cartridges is their high output level (between 2 and 5 mV), which means they are compatible with almost any phono input on a stereo component. Additionally, many moving magnet cartridges feature a removable and replaceable stylus, which can be important and convenient in the event of breakage or normal wear. It generally costs less to replace a stylus than the entire cartridge itself.
However, one disadvantage of using a moving magnet cartridge is that the magnets tend to have higher weight and mass compared to that of a moving coil cartridge. This greater value generally means that the stylus can’t move as quickly over the record, which inhibits its ability to track the subtle changes within the groove’s surface. In this respect, a moving coil cartridge has a performance advantage.
Before buying any cartridge, it’s important to read as many reviews as possible. No matter how many reviews you may read for a given cartridge, while you may find a general similarity between reviewers’ comments, you are just as likely to find significant disagreement as to the “sound” of a cartridge. Try to find a review using a similar tonearm and phono amplifier to your own or you may be disappointed after spending what could be many hundreds of dollars. In the end, you can never tell what a cartridge will sound like until it is installed in your system and has been used (broken in) for tens of hours.
How Does A Moving Magnet Phono Cartridge Work?
A moving magnet phono cartridge works by using a diamond-tipped stylus attached to a rigid cantilever, which is controlled in its movements by a suspension system. The movement created by the cantilever system when reading a record causes a magnet, attached internally to the cantilever, to move. This movement from the magnet interacts with coils of very fine wire inside of the main cartridge body, which each contain around 3,000 windings.
The result of this varying magnetic field is an electrical current, which represents the original music signal. This current is then sent down the tonearm wires, out the turntable, and over to the phono preamp (or phono input of your amp/receiver) for proper amplification and equalization.
Moving magnet cartridges are typically more affordable than moving coil cartridges because of the extra level of micro-engineering involved in moving coil manufacturing. The MM design is simpler to execute in production, thus they tend to be more affordable and have user-replaceable styli.
The Pros And Cons Of A Moving Magnet Phono Cartridge
When it comes to choosing a phono cartridge for your turntable, a moving magnet (MM) cartridge is often the most popular choice. Here are some pros and cons to consider before making your decision:
– High-output delivery: One of the advantages of a moving magnet cartridge is that it typically has a higher output level, which means it can work with almost any phono input on a stereo component.
– Removable and replaceable stylus: Many moving magnet cartridges feature a removable and replaceable stylus, which can be convenient in case of breakage or normal wear. It’s generally less expensive to replace just the stylus than the entire cartridge itself.
– Heavier weight and mass: The magnets in a moving magnet cartridge tend to have higher weight and mass compared to a moving coil cartridge. This can inhibit its ability to track the subtle changes within the groove’s surface, resulting in less transient detail.
– Less nuanced sound: Due to its heavier weight and mass, a moving magnet cartridge may not pick up as many delicate changes in texture as a moving coil cartridge would. This can result in a sound that lacks some precision in highs and lows.
Choosing The Right Phono Cartridge For Your Turntable Setup
When it comes to choosing the right phono cartridge for your turntable setup, there are a few important factors to consider. The first decision you’ll need to make is whether you want a moving-magnet (MM) or moving-coil (MC) design. Both are great options, but they have different characteristics and price points.
Moving-magnet cartridges have the magnet attached directly to the cantilever that holds the stylus. The magnet sits adjacent to two coils of wire. Moving-coil cartridges, on the other hand, have a fixed magnet and a mobile coil that moves within the magnetic field created by the magnet. Moving-coil cartridges tend to be more expensive than moving-magnet cartridges, but they also offer higher fidelity sound.
Another important factor to consider is the shape of the stylus. The shape of the stylus affects how it makes contact with the record groove. Conical shaped styli are the most common and affordable, but elliptical shaped styli have a smaller contact radius and can extract more musical information, especially high frequencies.
The cantilever is also an important consideration. It needs to be as stiff and light as possible in order to effectively transfer vibrational energy from the stylus tip to the magnet or other generating element. Aluminum alloy is the most common material used in cantilevers, but carbon, boron, and certain copper alloys are also used.
Trackability is another important spec that describes how well the stylus can track a modulated record groove. This spec is influenced by many factors including stylus shape, cartridge alignment, and tonearm compatibility. The higher the trackability spec, measured in micrometers (μm), the better.
Finally, it’s important to consider frequency response, channel separation, channel balance, and output level when choosing a phono cartridge. These specs describe how well the cartridge will perform and how well it will meet your needs. A flat frequency response ensures that no frequencies are given over- or under-emphasis, while high channel separation ensures that you don’t hear signals from one channel in your opposite speaker. Channel balance is important for both production quality and good basic design, while output level needs to be matched with your electronics.
Maintaining And Caring For Your Moving Magnet Phono Cartridge
To ensure optimal performance and longevity of your moving magnet phono cartridge, it is important to maintain and care for it properly. Here are some tips:
1. Keep your records clean: Dirt and debris on your vinyl records can cause excessive wear and tear on your stylus, leading to premature failure. Use a record cleaning brush or a record cleaning machine to remove any dust or dirt before playing your records.
2. Clean your stylus regularly: A dirty stylus can cause distortion and damage to your records. Use a stylus cleaning brush and a good stylus cleaning fluid to clean the stylus tip after every use. Avoid using isopropanol alcohol as it can damage the glue holding the stylus needle into the cantilever.
3. Check the tracking force: Make sure that the tracking force is set correctly according to the manufacturer’s specifications. Too much or too little tracking force can cause excessive wear on your stylus and records.
4. Check the alignment: Proper cartridge alignment is crucial for accurate tracking and sound reproduction. Use a cartridge alignment protractor to ensure that your cartridge is aligned correctly.
5. Handle with care: Always handle your cartridge with care, avoiding any sudden movements or impacts that could damage the delicate internal components.
By following these simple tips, you can ensure that your moving magnet phono cartridge delivers optimal performance and longevity, allowing you to enjoy your vinyl collection for years to come.