Moving magnet vs moving coil

[Fishtails]

Hi

This may have been done here before. However would like to know everyones opinion on this subject.

I myself have no idea about the difference so thats why i ask

Cheers!

[GlassWolf]

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

[Coffee Phil]

There are folks who know much more about this subject than I, but I have some nits to pick with this article.
He states that there are two types of cartridges. There are more than that. There are ceramic, capacitor, electret, and strain gauges also.

Even in the magnetic family there are moving coils, moving magnets, induced magnets, and variable reluctance. I think however most folks refer to magnetic cartridges other than moving coils as moving magnets.

He also states that moving coils have less mass than "moving magnets". Maybe for strictly moving magnets that could be true, but with rare earth magnets I'm not sure of that. From what I understand in the family of what we call moving magnets the effective tip mass can be lower and the compliance greater than typical moving coils. Imagine a couple of coils of wire attached to the cantilever.

OK, what is the big deal about moving coils? To keep the moving mass of a moving coil within reason the coils must be small and of relatively few turns. This results in low output voltage however it also results in a low output impedance. The advantage of low output impedance is of coarse that the effects of cable capacitance loading are largely swept away.

I believe that some cartridge manufacturers have picked up on this and are now making very low impedance "moving magnets" with the idea that you can have the better compliance of a "moving magnet" and the low impedance of a moving coil at the same time. I believe that this class of cartridge requires a moving coil input or step up transformer with a MM phono stage.

I am trying to find an example of this low impedance MM cartridge of which I speak but so far have had no luck. I'm pretty sure I did read about it and didn't just dream it up. I'll keep looking.

Phil

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

[Trackside]

Just as belt drive TT's are superior to direct drive then MC carts are superior to MM carts

[steve195527]

There are folks who know much more about this subject than I, but I have some nits to pick with this article.
He states that there are two types of cartridges. There are more than that. There are ceramic, capacitor, electret, and strain gauges also.

Even in the magnetic family there are moving coils, moving magnets, induced magnets, and variable reluctance. I think however most folks refer to magnetic cartridges other than moving coils as moving magnets.

He also states that moving coils have less mass than "moving magnets". Maybe for strictly moving magnets that could be true, but with rare earth magnets I'm not sure of that. From what I understand in the family of what we call moving magnets the effective tip mass can be lower and the compliance greater than typical moving coils. Imagine a couple of coils of wire attached to the cantilever.

OK, what is the big deal about moving coils? To keep the moving mass of a moving coil within reason the coils must be small and of relatively few turns. This results in low output voltage however it also results in a low output impedance. The advantage of low output impedance is of coarse that the effects of cable capacitance loading are largely swept away.

I believe that some cartridge manufacturers have picked up on this and are now making very low impedance "moving magnets" with the idea that you can have the better compliance of a "moving magnet" and the low impedance of a moving coil at the same time. I believe that this class of cartridge requires a moving coil input or step up transformer with a MM phono stage.

I am trying to find an example of this low impedance MM cartridge of which I speak but so far have had no luck. I'm pretty sure I did read about it and didn't just dream it up. I'll keep looking.

Phil

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

The pickering xlz range are low output/low impedance 0.3v@5cm/sec and 3.5ohm 7500 sounds superb

[ilkka313]

Just as belt drive TT's are superior to direct drive then MC carts are superior to MM carts

Far from the truth. Idler drive rules if you want to get the best result, I speak from experience, I've been spinning vinyl 40 years. I have sold all my belt drives, same with dds.
Having old Shure M75 and Japanese Jico SAS stylus MCs are not needed at all. Drawbacks with MCs is that you can not change the stylus, extra gain is needed and they are expensive.
Do not forget good MI carts like Pickering/Stanton 6xx series and Ortofon VMS series.

[Dr Pan K]

Just as belt drive TT's are superior to direct drive then MC carts are superior to MM carts

some MM have nothing to envy to many MCs just as some DDs have nothing to lose compared to some belt drives

(and yes i use a belt driven TT)

[steve195527]

I actually think its more to do with how the methods,MC,MM,belt,direct or idler are implemented rather that type per se:-there are good and poor examples of all!

[Blue Angel]

Hi fishtails

Your question may unleash some errr...firm opinions as the subject is a veritable rat's nest

I suppose I should be biased towards MC cartridges but I also have some firm MM and MI (and even a ribbon)favourite cartridges. Alas,some are no longer made as they date from the 70's and 80's.

A few MM/MI examples I'm very happy to live with: Shure V15 Type 111 (naturally), AT2003 VX, AT23a, Grace F-9E, Micro VF3200, Nagatron 360CE, AKG P8E and the latest AKG to fall in my lap so to speak - a P15MD which was someone's discard as it had a whacked cantilever. I heard it last night for the first time, now fitted with a Gyger FG2 stylus.

MM and MI cartridges have a bit of a drawback - sensitivity to capacitance and also require careful routing of armwires away from power leads.

ba

[Trackside]

Just as belt drive TT's are superior to direct drive then MC carts are superior to MM carts

I wasn't being entirely serious fellas

[thommo_work]

Some fell on stony ground.

[Coffee Phil]

Thanks Steve,

I knew this thing existed however I thought it was Shelter who made it.

Now I know.

Thanks,

Phil

There are folks who know much more about this subject than I, but I have some nits to pick with this article.
He states that there are two types of cartridges. There are more than that. There are ceramic, capacitor, electret, and strain gauges also.

Even in the magnetic family there are moving coils, moving magnets, induced magnets, and variable reluctance. I think however most folks refer to magnetic cartridges other than moving coils as moving magnets.

He also states that moving coils have less mass than "moving magnets". Maybe for strictly moving magnets that could be true, but with rare earth magnets I'm not sure of that. From what I understand in the family of what we call moving magnets the effective tip mass can be lower and the compliance greater than typical moving coils. Imagine a couple of coils of wire attached to the cantilever.

OK, what is the big deal about moving coils? To keep the moving mass of a moving coil within reason the coils must be small and of relatively few turns. This results in low output voltage however it also results in a low output impedance. The advantage of low output impedance is of coarse that the effects of cable capacitance loading are largely swept away.

I believe that some cartridge manufacturers have picked up on this and are now making very low impedance "moving magnets" with the idea that you can have the better compliance of a "moving magnet" and the low impedance of a moving coil at the same time. I believe that this class of cartridge requires a moving coil input or step up transformer with a MM phono stage.

I am trying to find an example of this low impedance MM cartridge of which I speak but so far have had no luck. I'm pretty sure I did read about it and didn't just dream it up. I'll keep looking.

Phil

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

The pickering xlz range are low output/low impedance 0.3v@5cm/sec and 3.5ohm 7500 sounds superb

[AudioSoul]

Just as belt drive TT's are superior to direct drive then MC carts are superior to MM carts

I am sure this comment was tung in cheek....

[Coffee Phil]

It seems this concept of a low impedance MM (actually variable reluctance in this case) is not all that new. In our very own library I found a low impedance version of the classic GE RPX intended for broadcast use.

http://www.vinylengine.com/library/general-electric/rpx-046.shtml

Of coarse low impedance is a relative thing. This old cartridge still has a higher output voltage than contemporary MMs. Just not as high as the regular RPX.

Phil

There are folks who know much more about this subject than I, but I have some nits to pick with this article.
He states that there are two types of cartridges. There are more than that. There are ceramic, capacitor, electret, and strain gauges also.

Even in the magnetic family there are moving coils, moving magnets, induced magnets, and variable reluctance. I think however most folks refer to magnetic cartridges other than moving coils as moving magnets.

He also states that moving coils have less mass than "moving magnets". Maybe for strictly moving magnets that could be true, but with rare earth magnets I'm not sure of that. From what I understand in the family of what we call moving magnets the effective tip mass can be lower and the compliance greater than typical moving coils. Imagine a couple of coils of wire attached to the cantilever.

OK, what is the big deal about moving coils? To keep the moving mass of a moving coil within reason the coils must be small and of relatively few turns. This results in low output voltage however it also results in a low output impedance. The advantage of low output impedance is of coarse that the effects of cable capacitance loading are largely swept away.

I believe that some cartridge manufacturers have picked up on this and are now making very low impedance "moving magnets" with the idea that you can have the better compliance of a "moving magnet" and the low impedance of a moving coil at the same time. I believe that this class of cartridge requires a moving coil input or step up transformer with a MM phono stage.

I am trying to find an example of this low impedance MM cartridge of which I speak but so far have had no luck. I'm pretty sure I did read about it and didn't just dream it up. I'll keep looking.

Phil

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

The pickering xlz range are low output/low impedance 0.3v@5cm/sec and 3.5ohm 7500 sounds superb