Turntable Cartridges: MM & MC


As mentioned in a previous article, vinyl never went away, and Turntables are making a resurgence.  This has brought with it a lot of questions.

One of the main questions is about cartridges; Moving Magnet vs Moving Coil: What is the difference?

 

 

The easy way to answer this question is: “look at the name”. 

One cartridge re-creates the sounds by moving a magnet close to a coil; Moving magnet.

The other creates the sound by moving the coils close to magnets; Moving coil.

But that basically, doesn’t explain anything.

So, the simple bits first.  Both cartridges consist of a small precious stone, attached to a cantilever.  It is the other end of this cantilever where the magic happens.

In the moving magnet style cartridge the magnet is attached to the back end of the cantilever, this magnet is then positioned between two sets of coils (in a stereo cartridge), this configuration creates a tiny transducer.  The small size and low mass of the magnet allow the stylus to follow the grooves in the vinyl faithfully without requiring a great amount of tracking force.

 

 

The moving coil cartridges are also small electromagnetic generators.  With the visible end looking the same; a small precious stone attached to a cantilever.

The “black magic” end however is reversed.  The coils are attached to the back end of the cantilever; these coils are moved within the field of a permanent magnet.

There are physical constraints within a moving coil cartridge; these constraints mean the coils, and the wire that makes them have to be tiny.  This small size then limits the voltage output from the cartridge which then requires a special MC phono pre-amp.

 

 

This coil and magnet configuration (MM or MC) then turns the movement into an electrical signal (this is the transducer aspect, for more information on transducers I would recommend your favourite search engine or the local library).  This electrical signal is then passed through a phono-stage (or pre-amp), from there to your amp, and then your speakers for you to enjoy.

So when push comes to shove the two systems do the same thing just opposite to each other.  This then opens up a world of heated conversation and debate about which cartridge is better… and that is a conversation I’m not willing to get involved in at this time.


Comments (1)

Not sure what prevamp to use

20 September 2018
Hi there. I have a question regarding what pre amp to use on my turn table. I have a Sony PsV725 modle and i was using a Sony amp which had a phone input and the turn table sounded great. The amp is now conked off and I'm using an Onkyo amplifier which doesn't have a phono input. I was told to buy a pre amp but I'm not sure what cartridge is on the turn table. MM or MC. Will any phono pre amp work on the Sony PSV725? Can u kindly check what cartridge is being used on the above Sony model turntable and advise if I need to buy a perticular amp based on MM or MC cartridge or any pre amp would solve the issue. Thank u....

www.completeaudio.com.au Response
Hi, The Factory fitted cartridge on the Sony PSV725 was a ND-155G. This was a Moving Magnet cartridge. With this in mind any Moving Magnet pre-amp will work with that Sony turntable. We hope this information helps, If we can be of any further assistance please do not hesitate to get in contact.

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