The Difference Between Moving Magnet and Moving Coil Phono Cartridge Types

If you thought your turntable cartridge was just the housing for your stylus at the end of your tonearm, think again. This is pretty high tech stuff.

The job of your cartridge is to translate mechanical movement into an electrical signal.

The stylus travels through your records’ grooves, vibrating the adjoining cantilever, which is connected to a series of wires in the cartridge, to bring you top quality, bone-shaking, life-affirming sound. Rubber suspension in the cartridge allows the cantilever to move and pivot so the stylus can accurately track grooves.

There are two main types of cartridge types: moving magnet and moving coil. Many of the principles remain the same for each.

Moving Magnet VS. Moving Coil Phono Cartridge

Moving magnet (MM)

This is the more common and cheaper of the two. A magnet sits in the cartridge at the top of cantilever, suspended between two coils for the left and right audio channels. The magnet vibrates between the two coils, and in doing so, produces a small current between them. While the magnet is tiny and has a low mass, it requires little downward tracking force to track the grooves of a record, but it is more than what’s required of a moving coil cartridge. Similar to the moving magnet cartridge is the moving iron (MI) cartridge. Only difference between MI and MM is that in place of a magnet is a sliver of iron, or similar light alloy at the top of the cantilever. As iron is lighter than the magnet, tracking force is reduced while accuracy is improved.

Advantages:

  1. High-output delivery;
  2. Typically compatible with most phono input on a stereo component;
  3. Often feature a removable and replaceable stylus;
  4. Nearly all tonearms are designed to accommodate MM cartridges.

Disadvantages:

  1. Higher weight and mass compared to moving coil;
  2. Doesn’t move as quickly which inhibits ability to track subtle changes within the grooves surface, which could be as slight as a millionth of a millimeter;
  3. Some audiophiles assert that because it exerts more tracking pressure than moving coil, this can affect playback quality and accelerate wear on your records.

Moving coil (MC)

Moving coil design is basically the inverse of a moving magnet cartridge. Two fine wired coils are attached directly to the cantilever with the magnet residing near the coils. Limitation in coil results in low output, making MC carts susceptible to noise and hum. Many audiophiles claim that the lower-pressure tracking required by MC carts mean it’s sonically superior. Of course, this comes at a price and added level of complexity. MC cartridges also need an RIAA preamp and additional amp stage or step-up transformer between turntable and RIAA frequency-compensating preamp.

Advantages:

  1. Greater agility when navigating micro changes in record grooves resulting in more sound detail;
  2. Improved accuracy and less sound distortion;
  3. Possibly more forgiving for your records in terms of wear.

Disadvantage:

  1. Smaller voltage, so often requires secondary preamp (sometimes known as a head amp). This increases voltage enough to be picked up by a phono output on a stereo component;
  2. Generally more expensive and require a more extensive hi-fi setup;
  3. Not suitable for all turntables/tonearms;
  4. You generally can’t remove and replace the stylus on a MC cart. If it’s worn or broken, you’ll need to contact the manufacturer to replace or repair it, or you’ll just need to replace the whole cart.

Which type of cartridge is right for me?

There are many factors you should take into consideration when choosing a new cartridge, like budget, stylus shape, and compatibility with your turntable and setup.

You can get great performance from either type, and have a wide range of choice, with prices ranging from about $25 right through to $15,000. When looking to upgrade your cartridge, think about your current setup, and talk to other audio fans who value similar things when it comes to playback, and do your research, and you’re bound to find a cartridge you love.

Check out moving magnet and moving coil cartridges on Gearogs!