Differences between MM and MC cartridges?
- Thread starter Serrana
- Start date
thedelihaus
Nocturnal transmissions
MM= moving magnet. The magnet is attached to the stylus shaft and moves by the coils, which are fixed in the body.
Similar designs to MM are:
MI= moving iron (magnetic iron moves by coils)
MP= moving permalloy (magnetic permalloy moves by coils)
MC= moving coil. The coils are attached to the stylus shaft and moves by the magnets, which are fixed in the body.
Both designs can be excellent. I use both, but seem drawn to the better quality moving magnet designs. Moving Coils are the belle du jour in the audiophile world right now.
MCs come in different output levels- the most popular typically HOMC (High Output Moving Coil) or LOMC (High Output Moving Coil). There is also a mid-road output model, a MOMC (Medium Output Moving Coil).
LOMC and MOMC may need additional components, such as a SUT (Step Up Transformer) or MC phono amplification stage.
A MM or HOMC cart can be used with the ubiquitous MM input.
Similar designs to MM are:
MI= moving iron (magnetic iron moves by coils)
MP= moving permalloy (magnetic permalloy moves by coils)
MC= moving coil. The coils are attached to the stylus shaft and moves by the magnets, which are fixed in the body.
Both designs can be excellent. I use both, but seem drawn to the better quality moving magnet designs. Moving Coils are the belle du jour in the audiophile world right now.
MCs come in different output levels- the most popular typically HOMC (High Output Moving Coil) or LOMC (High Output Moving Coil). There is also a mid-road output model, a MOMC (Medium Output Moving Coil).
LOMC and MOMC may need additional components, such as a SUT (Step Up Transformer) or MC phono amplification stage.
A MM or HOMC cart can be used with the ubiquitous MM input.
Serrana
Member
What do you mean when you say that MC cartridges are the "belle du jour" in the audiophile world?
So, when a MC cartridge lacks of a SUT or a phono amplification stage, the volume will be lower, is it true?
thedelihaus
Nocturnal transmissions
Belle du jour means "belle of the day", or the hot item of the current market.
Some fantastic moving coils are out there. My only concern is often some of the better moving magnets or moving iron or permalloy designs are forgotten, neglected and discarded in this thinking.
What I'm saying is there are great examples of both as you move up the food chain.
Well, simplified, yes. Output signal is lower, thus lower volume through a MM phono stage. Sometimes a MOMC can squeak by, and a HOMC is closer to the output of a MM/MI/MP, so can be used pretty easily with a MM stage.
Back to "belle du jour"- another good example is...
For a while, a high mass arm like the Infinity black Widow or Signet XK-35 was the rage for audiophiles, paired with a low mass, high compliance MM cartridge. Later, it became the fashion to use a medium or high mass arm with LOMC low compliance cart.
I've used both medium and low mass arms and MC and MM carts. Love 'em all.
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hifi_nut
Vintage? I´m vintage!
I believe you meant low mass arms, Paul, didn´t you?
thedelihaus
Nocturnal transmissions
You are correct.:yes:
jancumps
iRock
start nitpicking
In an MI, the iron(s) is (are) not magnetic, but just iron. This iron moves in a magnetic field generated by a fixed magnet placed 'somewehere else' in the cartridge.
The movement of the iron influences that magnetic field. That change is picked up by the coil.
end nitpicking
mhardy6647
Lunatic Member
MCs have been "the rage" since the late 1970s... and they have been around far longer. The Denon DL-103 has been in production since ca. 1962 and is (arguably) one of the best sound per dollar cartridge values extant. I use a DL-103.
The DL-103 is a low-output MC, so it requires a step-up transformer (SUT) or active pre-preamp ("head amp") between the cartridge output and a standard MM phono input on a preamp, receiver, or integrated amp.
http://www.high-endaudio.com/RC-Denon.html#103
The DL-103 is a low-output MC, so it requires a step-up transformer (SUT) or active pre-preamp ("head amp") between the cartridge output and a standard MM phono input on a preamp, receiver, or integrated amp.
http://www.high-endaudio.com/RC-Denon.html#103
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I beg to differ... MC's have been around since the start of LP's..
But through the 60's, 70's and early 80's, the market was dominated by MM/MI designs - from budget right through to top end.
In the mid 80's there was a move towards higher mass arms, along with MC cartridges.... and the pendulum has never swung back the other way.
There are plenty of excellent examples of both setup types....
Either design involves a bunch of compromises of various types - so the balance of these compromises will determine the quality of the sound, not the type of generator involved.
If you already have a TT and arm (and phono stage), then select a cartridge that will best suit those...
If you have heard a cartridge you absolutely love - then you need to make sure that your TT, arm and phono stage are setup up to get the best from it...
bye for now
David
But through the 60's, 70's and early 80's, the market was dominated by MM/MI designs - from budget right through to top end.
In the mid 80's there was a move towards higher mass arms, along with MC cartridges.... and the pendulum has never swung back the other way.
There are plenty of excellent examples of both setup types....
Either design involves a bunch of compromises of various types - so the balance of these compromises will determine the quality of the sound, not the type of generator involved.
If you already have a TT and arm (and phono stage), then select a cartridge that will best suit those...
If you have heard a cartridge you absolutely love - then you need to make sure that your TT, arm and phono stage are setup up to get the best from it...
bye for now
David
hifi_nut
Vintage? I´m vintage!
I agree with dlaloum. Think Ortofon RG-309 / SPU in the early 60´s. Later in that decade we witnessed the appearence of MM´s, and then, in the 80´s a revival of MC´s with the Super MC´s from Japan ( Supex comes to mind ) which was followed by High Mass arms Like Linn´s Ittok, to name just one.
Today the high end is still dominated by Low Output, low / middle compliance MC´s and medium / high mass arms, of which SME´s 312 is just an excellent example.
Today the high end is still dominated by Low Output, low / middle compliance MC´s and medium / high mass arms, of which SME´s 312 is just an excellent example.
Skylab
Watcher of the skies
There are other differences that must be taken into account besides the lower output of most MC's. Most low output MC's also require a lower input impedance on the phono stage to sound their best. Some MC cartridges can be used at the MM impedance of 47kOhm, but most LOMC cartridges sound best much lower, somewhere between 100-1000 ohms. The catridge manufacturer will specify the ideal phono stage impedance setting. Not all MC phono stages offer a selection here, but many of them do.
guiller
Toscaninichus Australis
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There are de-facto standards for impedance loads for MC and MM respectively... MC =100ohm, MM=47kohm.
But manufacturers treat these primarily as a guideline, and vary from these considerably... that is to say, the optimum loading for a cartridge may vary from the de-facto standard load.
Some phono stages therefore provide adjustable loading so you can optimise the loading for each cartridge used.
Many (most?) people are unaware that this also applies to MM/MI type designs - which in my opinion are even more sensitive to loading variation than MC types...
flavio81
Turntable technician
Given no budget restrictions you can make a fantastic cartridge, be it MM/MI or MC. However, the manufacturers currently prefer to use the MC system for their top cartridges. In the past there were many more top MM/MI designs.
The key advantage of MC is that a ruler-flat frequency response can be achieved more easily. It is not "lower moving mass than MM cartridges", that's an often repeated myth.
I don't think there's a disadvantage to MC cartridges except the lack of a replaceable stylus (except for some average quality MC carts) and the need for more voltage gain.
The key advantage of MC is that a ruler-flat frequency response can be achieved more easily. It is not "lower moving mass than MM cartridges", that's an often repeated myth.
I don't think there's a disadvantage to MC cartridges except the lack of a replaceable stylus (except for some average quality MC carts) and the need for more voltage gain.
Fairchild was making mono MC carts in the early 1950s.
Actually that is not quite true...
Getting flat frequency response with MC is much more difficult than with an MM/MI design.
With the MM/MI (High inductance) designs, you can use the loading (resistive, capacitive) and the inductance to "tweak" the frequency response - choose the rolloff point, boost an area where due to another effect there is a drop, etc...
As a result an economical cartridge can achieve a flat frequency response...
Yes - the economical aluminium cantilever has a resonance at 11kHz - but this balances out a drop in sensitivity due to economical solid permaloy construction, and then there is a rolloff due to high inductance which happens at 16kHz, but that is OK as it is balanced by an electrical resonance boosting at that frequency (the result of well designed and selected loading and inductance interacting). - This example is based on the Shure M97xE - but the AT120E and AT440MLa are very similar in their approach as are many other "budget" MM's
With an MC, or other low inductance design (including some MM's and MI's) - the cantilever response is "Naked" - the loading cannot be used to adjust the frequency response within the audible range.
So the cantilever and needle must be of sufficiently high quality to provide this flat frequency response without further adjustment.
This is why many "budget" MC designs are NOT neutral - they have cantilever resonances within the audible frequencies, and no counterbalancing electrical damping.
But with a really excellent cantilever, set up to have its resonances at up above 25kHz (in some cases above 70kHz), the audible range is left free of resonances, free of phase anomalies - and very very clean.
The best MM designs do exactly the same!
The Shure V15VMR used a relatively low inductance with relatively low capacitance to ensure flat electrical response with just a slight droppoff at the very top end.
The cantilever was designed with a resonance at 35kHz - which provided a very very slight rise at the very top of the audible range, and the resonance itself outside the audible range. (and suppressed by the droppoff generated by inductance and capacitance so it does not cause problems with the phono stage).
Cartridge internals used a laminated core to reduce HF droppoff as well.
Net end result -a flat frequency response, and a very neutral cartridge. (Other cartridges that use this type of approach include Ortofon OM30/40, Audio Technica AT150MLx, Stanton 881S, and other representatives of true TOTL MM design....)
On the other hand the Dynavector Karat - achieves the same using a very very short (1.7mm) cantilever made of solid ruby, with a low output MC design which keeps the audible range completely ruler flat, the cantilever design moves resonance up to above 70kHz - so within 20-20kHz it remains ruler flat.
Some have described this cartridge as sounding "CD Like" in the best of ways... another approach to neutrality.
The best designs of both MM and MC use the same cantilever approach - but at the under $200 price points, MC's simply cannot achieve a neutral response - whereas MM/MI's can.
(Not saying they cannot sound good...)
bye for now
David
Balifly
Listening
Is the graph large enough to be legible? :scratch2:
