Cartridge's , Please educate me

[Audio Al]

Cartridge's

I don't understand how they work

I have seen MM and MC types listed ,

Have found out that MM is moving Magnet , and MC is moving coil

Can anyone tell me why 2 types and what does one do that the other one does not do ?

Is one better than the other ?

Why the massive price difference ?

I am trying to understand this re my TT build

Thanks :)

[DSJR]

I'm typed out on this, but basically, the two types generally involve moving coil and FIXED coil types, the latter needing a magnetic material moving to generate the voltage in the coils, whereas the former has the coils moving in a fixed magnetic field.

Others here will come in with lengthy explanations and loads of opinions to describe which they prefer. The BEST moving coil types generally have a very low output and rescuing this output to best advantage of the physics and music usually involves spending lots of money, as well as often being far more demanding of tonearm and deck itself choice :lol: Fixed coil types can be very effective on the best examples, are cheaper to use and far more universal. Your money, your choice...

It may also be well worth Googling around and looking on the forum of Vinyl Engine, since I suspect this has been discussed ad nauseum on there ;)

[YNWaN]

http://stereos.about.com/od/stereoscience/a/mmmc.htm

[Macca]

As a general but not universal rule MC carts have a more detialed top end. You will hear the 'filagree detail' that reviewers bang on about. If you mainly listen to rock and pop recordings then you will not be missing much using a good MM. It's the more delicate material where you hear the difference and where the extrra money went.

In relation to your TT build it doesn't really matter, although if you are designing your own tonearm too then you might want to think about what type of cart you are going to end up using and design the arm to suit it.

[Audio Al]

http://stereos.about.com/od/stereoscience/a/mmmc.htm

:)

There are two types of phono cartridges, moving magnet and moving coil. The two types have different designs and performance characteristics. It all starts with the stylus or needle on the phono cartridge. The stylus travels through the grooves on the record moving horizontally and vertically, tracking the minute fluctuations in the groove that represents the music on the record. As it travels, the stylus creates a small audio signal generated by the proximity of a magnet and a coil. All phono cartridges have magnets and a coil – the difference is where they are located.
Moving Magnet Cartridge
A moving magnet cartridge (abbreviated MM) is the most common type of phono cartridge. It has two magnets on the end of the stylus (one for each channel), located inside of the cartridge. As the stylus moves, the magnets change their relationship with the coils in the body of the cartridge, generating a small voltage.

The advantages of a moving magnet cartridge are high output, which means it is compatible with any phono input on a stereo component. Many moving magnet cartridges also feature a removable and replaceable stylus. This is important in the event of breakage.

Its disadvantages are that the magnets have higher weight or mass compared to a moving coil cartridge, which means they can't move as quickly in the record groove. This inhibits its ability to track subtle changes within the groove. This is where a moving coil cartridge has performance advantages.
Moving Coil Cartridge
A moving coil cartridge is sort of the opposite of a moving magnet cartridge. Instead of magnets, two small coils are connected to the end of stylus located in the body of the cartridge. The coils are smaller than magnets and weigh much less, giving the stylus more agility when navigating the constantly changing record grooves. In general, a moving coil cartridge traces the grooves better because of its lower mass and provides more detailed and accurate sound quality.

One disadvantage of the moving coil cartridge is that it generates a smaller voltage and requires a secondary preamplifier, sometimes known as a head amp. The head amp increases the voltage enough for a phono input on a stereo component. Some moving coil cartridges have higher output and are compatible with a standard phono input, but its output will be somewhat lower than a moving magnet cartridge.

The stylus is also not user replaceable in a moving coil cartridge and must be replaced at the factory or the entire cartridge discarded if the stylus is broken.

Both types of phono cartridges will provide good performance, but if you want the best, select a moving coil cartridge.


Thanks for the link , its a bit clearer now , MC is better but more complicated and does not have removable needles / styli

;) Cheers

[John]

I do not know which is better I think its about preference I use a MM that has better mid and bass than a Decca Referenece cost peanuts compaired to what the reference cost, the Decca wins out in treble; lots of good mc and mm cartridges a lot will depend on your arm and phono stage

[DSJR]

Decca's are not universal cartridges I'm afraid, and still frail and not open to mishandling in any form, hence the well deserved reputation for heaven and hell in owning and using them.

The best MC types for whatever reason, do have a solidity to the sound which isn't always shared in most fixed-coil types I've found.

[John]

Dave I love Decca's I certainly in the heaven side with my feelings towards them

[walpurgis]

Its not a universal rule that MCs are best or that MMs are inferior.

I've heard some pretty poor sounding MCs and great sounding MMs. Many years ago there was no distinct price gap between MM and MC cartridges, I think its largely a trend or fashion that has led to the priciest cartridges being MCs these days.

I'm sure if modern techniques and materials were used to produce a new MM type the results could be outstanding (Shure take note).

I'm not including Deccas in this as they are a breed apart (bit like my old ADCs).

[Barry]

To start with, it's not a division between moving magnet and moving coil; rather it is a distinction between moving coil and fixed coil. Both of these generators can be described as electrodynamic and rely on Lenz's law, which describes the voltage output in terms of the rate of change of magnetic flux. How the magnetic flux is changed (by the stylus tracking the record groove) depends on the detailed design of the cartridge generator.

In moving coil designs, the coils are attached to the stylus (and hence move), whereas the magnets providing the magnetic flux are fixed. Moving coil designs tend to have a low output because the number of turns of the coil are small, so as to keep the moving mass of the coil low. The compliance of the cantiliver also tends to be stiffer, so as to keep the coil centred with respect to the fixed magnets. Because the (moving) coil has fewer turns the inductance is low (of the order of microhenries), so there is no problem with resonance with the capacitance of any SUT or SUD (head amp).

Fixed coil designs permit an number of options; the only constant is that the coils are fixed. How the magnetic flux changes with grove modulation can vary. True moving magnet designs (for example Shure cartridges) have the magnets attached to the cantilever. In induced magnet designs (for example ADC, Sonus and Decca designs), the magnetic flux is induced in a ferromagnetic cantilever by a fixed magnet within the body of the cartridge. These designs are also known as moving iron designs.

Then there are those designs known as vari-reluctance types. In these the the magnetic circuit between the fixed magnet and the (fixed) coils is completed by the cantilever, which because it moves with the record groove, modulates the magnetic reluctance (the magnetic equivalent of electrical resistance). Vari-reluctance designs should not be confused with induced magnet (or moving iron designs), since the latter do not have a complete magnetic circuit. In all cases because the fixed coil has a greater number of turns, the output is higher as is the coil inductance (of the order of hundreds of millihenries); the latter creating a high frequency resonance with the input capacitance of the input stage of the preamp.

Whether the dog "wags the tail" or the tail "wags the dog", ought not to make any difference. However, it is generally acknowledged that moving coil designs make a better job of extracting and reproducing what is encoded in the record groove. That is not to say that there are no good quality fixed coil designs out there. There are, such as the Nagaoka designs, the ADC 25 and XLM designs, the AKG P8ES, the B&O MMC 20CL and the Technics EPC-305MC - plus of course that exemplar of the fixed coil design: the Decca.



Then there are the 'rara avis', those cartidges that are not electrodynamic in operation. There are several: those that use the record groove to modulate the capacitance between an electrode on the cantilever and a fixed electrode on the cartridge body (for example the Wethers FM design, which used the change in capacitance to frequency modulate a fixed frequency signal supplied by an oscillator).

There are some designs that use the moving cantilever to modulate a light beam between an optical source and a detector (Sony designed one such cartridge) and those that use the strain gauge principle, wherein the cantilever twists a metallised ceramic, causing changes to the electrical resistance. The Soundsmith cartridge is a recent example of such, but there were forerunners with the Miniconic design.

Finally there are (or were) the piezoelectic cartridges which exploited the piezeoelectric effect where certain crystals (such as Rochelle salt) develop a potential difference across them when twisted (or squeezed - 'piezeon' is the Greek to squeeze) and are thus commonly referred to as crystal cartridges. Later developments used a piezeoelectric ceramic (and hence were called ceramic cartridges). They were popular as cheap transducers in the fifties and early sixties; the best example being the Decca Deram cartridge.

[Patrick Dixon]

Decca's are not universal cartridges I'm afraid, and still frail and not open to mishandling in any form, hence the well deserved reputation for heaven and hell in owning and using them.


I don't think they're frail at all. No exposed cantilevers to get snapped off - the only thing I've heard is not to clean the stylus with liquid as it gets wicked up and damages the damping material.

They are only hell if you don't match or set them up them properly, and then the hell is knowing how close you are to heaven but not quite being able to get there.

[Audio Al]

Barry :eek::eek:

God you know your stuff :stalks:

Thanks for the answers

My head is spinning now :lol:

[walpurgis]

Bet you're glad you got all that off your chest Barry.

The Deram is possibly the best 'ceramic' type cartridge, but I found the dearer Acos designs to give as good aural results.

[Clive]

Its not a universal rule that MCs are best or that MMs are inferior.

I've heard some pretty poor sounding MCs and great sounding MMs. Many years ago there was no distinct price gap between MM and MC cartridges, I think its largely a trend or fashion that has led to the priciest cartridges being MCs these days.

I'm sure if modern techniques and materials were used to produce a new MM type the results could be outstanding (Shure take note).

I'm not including Deccas in this as they are a breed apart (bit like my old ADCs).
Re modern materials, my MM AT150MLX uses a boron cantilever and has a line contact tip; all for just over £200 (I was lucky enough to escape import duty). The results are indeed outstanding.

[walpurgis]

Re modern materials, my MM AT150MLX uses a boron cantilever and has a line contact tip; all for just over £200 (I was lucky enough to escape import duty). The results are indeed outstanding.

I must admit, I haven't tried an AT MM design for years. They always were good (along with Nagoaka). If any company can advance MM technology it would be Audio Technica in my opinion.

[RobbieGong]

I must admit, I haven't tried an AT MM design for years. They always were good (along with Nagoaka). If any company can advance MM technology it would be Audio Technica in my opinion.

And Ortofon I'd say :)

[doodoos]

On a purely practical note mm stylus replacements are a hell of a lot cheaper as they're diy friendly whereas mc's are not.

[vacdac]

Lol Robin....I hardly think that replacing a stylus on an MM cart is deserving of DIY status.

I do though get what you're saying & I hang my head in shame at the lengths I would go to many years back to get others to set up new carts for me. :lol:

It's rarely the case these days though that there's a huge saving, when comparing replacement stylus cost to buying a whole new cart & once you factor this in replacement costs are often not wildly different for either type of cart.

Certainly once you're above budget level & talking £4/500+ MC carts having a rebuild/re-tip can start to look very cost effective. How much is a replacement stylus for the Ortofon 2M Black compared to buying a whole new cart? & does this stack up as wildly different to their 25% discount exchange scheme offered on their MC cart range?

B.R.

Chris.
On a purely practical note mm stylus replacements are a hell of a lot cheaper as they're diy friendly whereas mc's are not.

[Barry]

Bet you're glad you got all that off your chest Barry.

The Deram is possibly the best 'ceramic' type cartridge, but I found the dearer Acos designs to give as good aural results.

Meaning?

[walpurgis]

Meaning?

Meaning there are other contenders for 'best' I suppose.

Also, there were some advanced strain gauge type cartridges being developed in the seventies and into the eighties and these possibly used ceramic piezo elements. So who knows?

[Barry]

Strain gauge cartridges do not generate a voltage per se, the record groove modulates the resistance of the strain-gauge element and so they need a power supply and an anti-RIAA equalisation network. Apart from the current Soundsmith design, the only other cartridge using the strain gauge principle was the monophonic Miniconic design of the '60s. (There was a Micro Audio MA 2002 cartridge which may have used a similar principle.)

Ceramic cartidges and crystal cartridges do generate a voltage, and require a different equalisation network to conform to the RIAA curve.

I have little experience of any of them, save to say the Decca Deram was well regarded in its day.

[PaulStewart]

Garrard SP25 Mk2 Decca Deram Teleton amp and a couple of EMI elliptical speakers with 2 3 inch tweeters on the front in home made cabs............... Ahhhh! teenage bliss and girls wanted to come back to mine to listen to music:eyebrows:

[Barry]

Ah the Teleton amp! This was discussed some time ago in a rather nostalgic thread (http://theartofsound.net/forum/showthread.php?t=6989&highlight=Teleton+amp)

[walpurgis]

Strain gauge cartridges do not generate a voltage per se, the record groove modulates the resistance of the strain-gauge element and so they need a power supply and an anti-RIAA equalisation network. Apart from the current Soundsmith design, the only other cartridge using the strain gauge principle was the monophonic Miniconic design of the '60s. (There was a Micro Audio MA 2002 cartridge which may have used a similar principle.)

Ceramic cartidges and crystal cartridges do generate a voltage, and require a different equalisation network to conform to the RIAA curve.

I have little experience of any of them, save to say the Decca Deram was well regarded in its day.

You certainly know your stuff Barry.

Correct me if I'm wrong, but I seem to recall Panasonic/Technics were working on an advanced piezo ceramic cartridge design at one time, probably late seventies. I don't know whether anything came of it.

The Micro-Acoustics cartridges were electret designs, operating on a similar principle to ceramic/crystal types.

[sq225917]

Pete over on the Wam has a Panasonic/Technics, there was also Sao Win.

[hifi_dave]

Jeweltone Ribbon.

[Barry]

You certainly know your stuff Barry.

Correct me if I'm wrong, but I seem to recall Panasonic/Technics were working on an advanced piezo ceramic cartridge design at one time, probably late seventies. I don't know whether anything came of it.

The Micro-Acoustics cartridges were electret designs, operating on a similar principle to ceramic/crystal types.

Yes, you're right about the Micro-Acoustics MA 2002 being an electret design. I had forgotten about it, just as I had forgotten the correct name!

Apropos ceramic cartridges, I think they have had their day and I can't imagine anyone developing the principle further. The Sao Win design sadly didn't come to anything (nor did his turntable).

However, I would have said the same about strain gauge cartridges but then up pops Soundsmith with their design.


The Jeweltone ribbon cartridge was an electrodynamic design - a "moving coil" cartridge having a one half turn winding to the coil, i.e. a ribbon. Imported into the UK by the owner of the Absolute Sounds dealership, it almost immediately sank from view. Shame, as I would liked to have heard one; the (monophonic) Ferranti ribbon cartridge of the '50s was considered state of the art and was favoured by the late Peter Walker of Quad.

[hifi_dave]

The Jeweltone was an excellent cartridge, very fast, detailed and dynamic. The JR1 (was it ?) was an integrated into the plastic headshell jobbie, whilst the later JR3 was a conventional screw mount. I still have one here.

The original importer was a HK friend of mine, who brought them in for friends and acquaintances. Ricardo, in turn, brought them from my friend but did very little with them.

[Barry]

The Jeweltone was an excellent cartridge, very fast, detailed and dynamic. The JR1 (was it ?) was an integrated into the plastic headshell jobbie, whilst the later JR3 was a conventional screw mount. I still have one here.

The original importer was a HK friend of mine, who brought them in for friends and acquaintances. Ricardo, in turn, brought them from my friend but did very little with them.

Do you have it set up Dave? What is the output? I would imagine it to be very low.

How about getting it set up in a suitable arm fitted to your Thorens TD124/II, and I'll come over and listen to it? ;)

Regards

[hifi_dave]

I'll have to dig it out. I think I know where it is, just so long as it's not gone the way of some other exotic cartridges I had - vanished, when I shut my shop.

I can't mount it on the TD124 as that has an SME improved, which won't balance the JR. I do have other TT's though.

The output was low but worked perfectly into the x'mers I used back then, one of which I still have.

[nat8808]

Here's my take on how they work.

When you move a coil of wire in a magnetic field, the electrons start to flow as you move it. Move it back and forth constantly and you create an electric signal along the wire.

There's no difference between the coil moving in the magnetic field or the coil staying still and instead moving the magnetic field.

A magnet creates such a magnetic field.

To create a signal in a cartridge from the movement of the stylus in the groove, you can choose to make the magnet move with the stylus or the coil to move with the stylus. Stereo is made from two sets of coils, each responding to movement in directions at right angles to each other - this is done diagonally, the groove on a record is a 'V' shape, one side of the V being left channel and the other right channel.

That's my simple explaination!

Further to that if you change the sizes of the magnetic field (i.e. bigger or stronger magnets) or the size of the coils, you get different strength signals and kind of different 'resolutions' for want of a better phrase.

If you want the stylus to move very quickly in response to the fine details of the record groove then you don't want it to have a massive weight on the end as it will slow it down (inertia). The possition and weight of the coil or magnet on the stylus will change it's behaviour, reaction to the grooves like changing its resonant frequency, ability to respond to details in one frequency range compared to another frequency range etc.

My take on the MC/MM thing is that if you want more detail, you want a strong magnetic field to create as much signal per bit of movement of the stylus as possible - i.e. a strong magnet which really means a bigger magnet. Because of the weight of a lump of magnetic material, you get to a point where its just not going to work on the stylus and so you want the magnet to be the fixed part, and instead the coils to be on the stylus - this an MC cartridge.

My other, extrapolated take on MCs (which may be misguided) is that the smaller and lighter the coils, the better the detail extraction from the record. The smaller the coils though, the smaller the signal output - so I always assume that a very low output will gather the finest detail, all else being equal. This could all be ruined by a poor amplification stage though as you're relying on that more heavily.

The coils are the more fidley parts to produce so anyone wanting to mass produce cartridges will rather they are not delicately placed on the end of the stylus, better that they are completely fixed to main body. It is then easy to afix measured sizes of magnet on the end of the stylus instead. Hence the styli can be made relatively cheaply and made replacable.

The relative ease of manufacture also should mean that, up to a point, MM carts will be much better value for a given quality of sound!

The potentially fidley nature of winding the tiny coils and putting them on the end of a fancy stylus (MC) draws people in and becomes an art and human facination, the kind of thing traditional Japanese culture lends itself well to. So you have people individually making MC carts by hand and hence very high prices (or at least, you have the sellable image that they have been hand made and falsely charge a high price..).