MM or MC

cam somebody tell me the difference? all i know is that one is much louder.

 

The audio signal, snaps, crackles and pops, etc are generated in the, er, generator. EMF is generated by relative movements between a magnet & a coil.

Cartridges where the magnets are joined to the stylus cantilever are called 'moving magnet' (MM) carts; conversely cartridges where the coils are joined to the stylus cantilever are called 'moving coil' (MC).

MM carts in general have a higher EMF generated & so are higher output compared with MC.

The coils have less inertia (resistance to movement) because they are lower mass (lighter than the magnets), hence you get a lot more low-level detail with an MC cartridge.

 

Hi

The Devil has pointed out the main differences between the two but both methods have their strengths & weaknesses.

With a moving magnet, the magnet on the end of the cantilever is in a field of coils. The more coils there are the bigger the output. This increase in coils will push the resistance up & also increase the inductance. This can make the cartridge more load sensitive. It can also cause high frequency roll off. A bigger magnet will increase the moving mass & mean subtle changes in the groove will not move the stylus/cantilever assembly meaning information is lost.

This problem is much lower in moving coils. Most moving coils have a much higher frequency response. The moving coils suffer from low output due to the small number of coils in a magnetic field. You need a step up amp or transformer (which in turn can bring there own problems).

To improve output, you can increase the number coils or/& use a more powerful magnetic material. This increase mass will bring it's own problems.

Also you have to look at the cartridge body which needs to be rigid & offer a good support for the coils & magnet. You need to look at the cantilever which needs to be rigid so that any movement picked up by the stylus is transmitted to magnetic field without any distortions. You also need a very good stylus profile that can follow the changes in the groove.

To do all these things to a high standard puts the price up. That's why so cartridges can be very expensive.


SCIDB

 

right.. i see... sort of...

so what would you suggest for my rega 3? mm or mc? my amp supports both.when i do eventually get around to it i will want to spend around 150 squids. well i wont actually want to but thats as high as i will allow my self to go.

 

150 quid will get you a good MM, or a cheap MC. I'd go with the MM option. To be fair, I'm usually hard pressed to say either type is better except on a perfectly set up TT of PT TOO standard or above. To be honest, I think that TT set-up, power supply implementation, and whether the TT / arm likes the cartridge is more important.

Also with MC, the amp stage has to be of high enough quality to make it worthwhile as well, and seeing as MM stages are usually (not always) infinately better on standard integrated amps than their MC counterparts (most don't even have these fitted even!) then MM is as far as I would go.

Cheers

 

Timpy I would have to totally disagree, in my experience MM has never sounded as good as an MC.

Surely we can agree that in terms of quality MC is generally better

 

yikes thats just about enough for a decent budget cart.

I have a horrible feeling your phono stage might be pants, which would be a horrible waste of a good cart...

And yet... if you take £50-£75 off your budget for a phono stage then the amount left for a cart will be pretty poor.

Hmm.

Id suggest first thing is to sus the quality of your phono stage. Borrow a budget project or rega phono stage.. try it with your existing cart - if its leagues ahead, get that instead for now!

If its not much better than the one in your amp, Id go for a budget favorite like a Benz, or a goldring 1042, or a baby dynavector.

At £150 you could go either way to be honest, but your biggest worry IMHO is that your phono stage might put a damp squib on the whole proceedings...

HONESTLY, if you havent experienced the difference between a naff phono stage and a good off-board one - its LEAGUES more of a difference than what you'll get going from a £50 cart to a £150 cart.

All IMHO, but Im right damn it! lol

 

So if I invested in a £50 off board phone stage my turntable will be transformed?

 

depends what the one in your amp is like mate.

Theres a Lehmann (think thats how you spell it) black cube going in E-bay for about £70 which is a real bargain too.

Certainly, in my experiences I'd rather go to a £150 cart with a £250 phono stage, than a £500 cartridge (or more) with a poor phono stage.

IME phono stages make an amazing difference

Chris

 

So does Tone arm wire

 

Hi garyi

I'm with you of course, everything else being equal, MC is better.

But I was talking within the available budget, with 150 pounds to spend, about the price of a decent Rega phono amp, there's not much to play with. I'm sure (as has been mentioned) that blowing 150-200 quid on a (not exceptional for the type) MC cartridge and leaving it to the mercies of what the Wharfedale passes off as a MC input, isn't likely to sound as good as a decent 50 quid MM (Rega for example) and a Rega phono amp. There are other makes of course, but Rega is as good a place to start as any. I've always liked Goldrings.

If you use the phono stages in the Wharfedale, I would expect them to be half decent, especially as the amp was designed and launched when vinyl was at least cd's equal (in popularity), and it is a good amp, but they won't equal the capabilities of a semi decent out board device, and the MC stage is harder to get right on a budget.

I still vote MM for this one.

Cheers

 

sounds about right i guess.perhaps i should buy a phono stage for now(i will always have it) and worry about a cartridge later.

 

Hey Rob,

Here is a TT etc FAQ link which might prove useful to you (well it did to me anyway.) http://forum.hifichoice.co.uk/viewtopic.php?t=6467




Enjoy the music!!

Lawrie

 

The main reason that I have been using Naim preamps is the excellence of the built-in phono stage.

This is also the main reason that I am rather disappointed with Naim introducing the NAC 552 preamp which, at £12, 000, doesn't include a phono stage.

 

Ideed. Naim's phono boards are so excellent that they mask the LP12's warbling.

 

Alex, can anything mask your warbling?

[arf]

 

Of course, it is surprising they didn't manage to find any room in the budget for that one.

Then again, no doubt they do (or will) offer a seperate one for about half that figure, just so that you can be sure you are getting the best.

Cheers