MM or MI Cartridge?


Currently using an SPU Royal N with a Viv Labs 9" and Kuzma Stabi R, and I am looking for a great Moving Magnet or Moving Iron Cartridge that I won't feel short changed by.

A couple of options I am looking at are the Grado Reference "The Reference" Wood 2 and the Audio Note IQ3, has anyone had the opportunity to compare these cartridges, and any other options I should consider that you have heard against either of these cartridges?

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@terry9 I pretty clearly stated there were a lot of other factors " There are other factors, to be sure, vibration control, compliance, tracking ability, and several more but all of those can be controlled independently of the electromagnetic performance of the generator which is determined in large by the cartridge designers choice of MC, MI, or MM. I haven’t gone into cartridge loading which is important, but cannot compensate for the hysteresis inherent in the design." Viewed as a Venn Diagram, there’s a lot over potential overlaps. I have been a big Grado Fan for 50 years, but unfortunately Grados hum on my JMW Memorial 10.5 3D, and no amount of grounding magic could fix it.

@wolfie62 There are many forms of hysteresis, defined as the delay between input and output. What you describe is a single type, and seem to go further to claim that an aircore inductor has no time constant associated with its inductance. I do not claim any reduction in speed, but rather a delay in propagation. Faraday’s Law put it this way: "The electromotive force around a closed path is equal to the negative of the time rate of change of the magnetic flux enclosed by the path" Please note the ’time rate of change’. A magnet may also have more than one possible magnetic moment in a given magnetic field, depending on how the field changed in the past. Plots of a single component of the moment often form a loop or hysteresis curve, where there are different values of one variable depending on the direction of change of another variable.

In the elastic hysteresis of rubber, the area in the canter of a hysteresis loop is the energy dissipated due to material internal friction. Cartridge suspension materials such as rubber and some polyurethanes exhibit a high degree of elastic hysteresis, as do cantilever geometries and materials.

@lewm notes: "the three types do group well apart from each other if you base it on inductance. LOMCs are always much less than 100uH (micro-Henries). Many are actually down in the 10uH and below range. Whereas MI types typically measure in the low mH range, and a classic MM will measure 400mH and higher. The difference between 10uH (for a LOMC with low internal R) and 500mH (for a classic MM) is 50,000X!"

Although I do believe that the general ’flavor’ of MM, MC ,and MI tend to group along those lines, It is certainly NOT the only or deciding factor. However, I don’t think any serious listener would confuse, say, an Ortofon MM, with any number of MC carts, or would deny that Grados have a unique family character.

@jasonbourne71 

I auditioned the Soundsmith Strain Gauge for over two hours at Soundsmith's music room. It requires its own power supply/phono stage and will not plug directly into a line level input. It is a very dramatic cartridge leaning heavily on the bright side. It will also not handle the highest groove velocities. Were I to get another Soundsmith I would opt for the Hyperion which like the Voice is very neutral and an amazing tracker.

I own several different cartridges from different brands, and here's my opinion (emphasis on opinion).


Didn't care for ANY of the Nagaoka line (had the opportunity to get them at cost, so I bought several in the line). I love detail and clarity, and I found them too warm and fuzzy.

Love the Ortofon line. Again, have heard at least a dozen representing 3 different lines. Can't go wrong with the 2M Black LVB 250 or the MC Cadenza Bronze.

I'd also look at the Goldring 1042 MM. It's a happy medium between Nagaoka and Ortofon. I'd recommend their Moving Iron 2500 as well, but it looks like they don't make it anymore.

Finally, I LOVE Clearaudio's Charisma V2. Everything that's great about MM and MC combined. However, it BETTER be great considering it's price. 

There, THAT should thoroughly muddy the waters.

@mglik The kitty is probably empty after buying the Epoch 3, so this may be immaterial. John Wright sold his business at the last moment, and a few people have reported having Decca cartridges serviced satisfactorily by the new tech. There was even a new version of the Reference promised, but I see that has gone from their webpage now. Maybe there’s more info on their Facebook page, but I don’t do Facebook. See:

https://www.londondecca.com/

Dear @lewm : Agree, inductance is not what inherently makes the differences between MC/MI/MM.

 

Like you I own and owned several of those 3 cartridge categories and I found out 2 distinctive characteristics during playing in favor of LOMC: transient response " speed " and low bass quality that’s tight/tied with lower over-hang and better definition.

Some of the best vintage/today MM/MI are really close to those LOMC characteristics but not at the same level that makes the differences in favor of the MUSIC.

MM/MI cartridges have a disadvantage against LOMC cartriidges that is that normally phono stage designs are designed with the LOMC in the designer minds not for MM/MI cartridges where the needs for these cartridges are really different and almost no today phono stages can fulfill it and not only because the units did not comes with the load capicitance and impedance alternatives it to fulfill each single MM/MI models but for the input gain stage .

In the phono stages that can handled both kind of designs the manufacturer treats the MM/MI option as a " side line " been the main target the LOMC facilities.

I still own 2 vintage Grado cartridges from where comes the today Epoch3 and can’t even those 2 LOMC characteristics I mentioned before. Yes, sounds really good those Grado’s and overall it depends on the owner MUSIC/sound priorities but at the end those two differences persist if we have the " rigth " rig to be aware about or interested on those characteristics level quality performance.

 

Regards and enjoy the MUSIC NOT DISTORTIONS,

R.

I feel privileged and fortunate to have a Grado Epoch3 MI cartridge.

It instantly replaced my, highly regarded, Lyra Atlas SL.

By that I mean it did not “cream” the Lyra, but it greatly surpassed it in, the always vital and central, musicality. Most important to me, voices sound more natural.

I bought the Grado because I was curious about MI. Everything I read about the, somewhat legendary, MI Decca London Reference made me long for that kind of sound. But the Decca  turned out to be out of production. And those who own them seem to hold on to them tightly. And I don’t think there is anyone who rebuilds them. I may be wrong about that.

MM (MI) or MC? One can’t generalize. But, surely, there are now outstanding cartridges of all types. 

Wolfie, Good point about the relationship between hysteresis and core material, or lack of same. But to my observation, the three types do group well apart from each other if you base it on inductance. LOMCs are always much less than 100uH (micro-Henries). Many are actually down in the 10uH and below range. Whereas MI types typically measure in the low mH range, and a classic MM will measure 400mH and higher. The difference between 10uH (for a LOMC with low internal R) and 500mH (for a classic MM) is 50,000X! But I still stand by my reasoning (see above) and my listening experience that leads me to believe the difference in inductance does not make LOMCs inherently superior to MI and MM types.  So, you and I agree on the end point.

The big difference between MC/MI/and MM cartridges boils down to a very few factors, most notably stylus profile, of which much ink has been spilled, and inductance, which is rarely mentioned. Moving coil carts have the lowest, then Moving Iron, and then Moving Magnet. why does this matter? Inductance directly relates to a property called hysteresis, the delay between a change in input and a change in output. Google 'hysteresis curve' and you'll see the characteristic 'S' shaped hysteresis curve, and its return, the hysteresis loop. Ultra low output MCs sound fast and detailed in large because they have low inductance, thus low hysteresis. MI carts like Grado and Soundsmith  have greater inductance, roughly in the 50mH range, but the difference is incremental. Most Moving Magnet carts have 10X more inductance around 450-550 mH and accordingly 10X more hysteresis, more delay between changes in input (stylus motion) and a change in output voltage. They simply cannot respond without 'smearing'. The tradeoff in general is output voltage, where MM carts win by a mile, thus making preamp design easier and more forgiving. This is why most MC carts require an additional level of gain, and usually worse S/N ratios. There are other factors, to be sure, vibration control, compliance, tracking ability, and several more but all of those can be controlled independently of the electromagnetic performance of the generator which is determined in large by the cartridge designers choice of MC, MI, or MM. I haven't gone into cartridge loading which is important, but cannot compensate for the hysteresis inherent in the design.
 

Bunch of ill thought out hooey here!

Hysteresis refers to the coil core material ONLY. There is no hysteresis in an air core coil, or a non-magnetic core material, such as aluminum or plastic. Iron alloy *can* have hysteresis, depending on the alloy or physical form. Hysteresis results in loss of magnetic flux, but no loss in speed, as magnetic flux is transferred at the same speed of light as do electrons travel through a conductor. Resistance to electrical flow or magnetic flux may decrease energy transfer, but NEVER speed! You need to go back and study EE 101! 
 

Laminated coil core materials exhibit very little hysteresis, as used in the Shure M24, V15-III, IV, V. 
 

MI cartridges, as a subset of MM, have wide ranging inductances, as do MM carts. There is no “set” range of inductances just because a cart is MI, or MM. To say there is, displays a complete ignorance of cartridge types and design over the last 7 decades. Inductance of MM/MI carts determines output using a given magnetic flux density. Cartridge loading affects FR of a given combination of inductance and magnetic field strength. 
 

MC, or MI/MM just categorizes which comprises you choose to accept. There is no inherent superiority. Whichever you choose, choose wisely. There are so-so MC carts, and also MI and MM carts. Don’t use a broad brush, using a bad example of an MC to condemn MCs, or condemn all MMs or MI carts because you had a so-so example.

Forgot also to mention typical compliance numbers that might affect response time. MCs typically exhibit lowest compliance. The exceptional MCs that exhibit higher than average compliance are the ones I like best.

Moving coil cartridges do indeed have the lowest inductance of any of the three types, by far, but they also have the highest moving mass. Moving iron type cartridges have the lowest moving mass on average. MM types are somewhere in between. Therefore, any response retarding effect due to hysteresis caused by inductance is compensated for by very low moving mass in the case of the moving iron cartridge. Which may explain why the general conclusion that MC cartridges exhibit superior high end clarity, based on hysteresis alone, does not conform to my long-term observations of the performance of the three types of cartridge.

If you are unwilling or unable to seek out a Decca Super Gold, +1 Nagaoka MP500. Also look at the Audio-Technica AT150ANV if you want detail and open-window clarity. I recall Fremer giving it very high marks. The Grado and Goldring (Audionote) are pretty warm sounding by some accounts.

Dinov is right.  Since the output is somewhere in between an MC and a MM, you will have to experiment with your phono preamp setting.  Mine only had 2 settings, MM and MC.  One sounded fat, the other was weak.

I have a Grado reference in one of  my vintage systems. I have it on a AR XA with a Mayware tonearm that I refurbished. It is an outstanding cartridge once you get it dialed with beautiful vocals and surprising bass. 

@panzrwagn , you appear to suggest that nothing can touch a MC. I beg to differ.

For years I used a higher end Koetsu, a great MC by any standards. Last month I replaced it with a top Grado, and the difference was immediately obvious. The Grado has more dynamics, more clarity, and more sweetness. Smoothness. Not to mention, notably better tracking. That's on an air bearing TT, air bearing tonearm, and ESL's.

I have a Viv 9" as well, with the carbon fiber tube. The Royal N hasn't spent that much time on it, I'll have to give it another chance.

My favorite MM/MI's are all from the golden age of analog. The Denon 109D (with Jico stylus) is an exceptional all-around performer with a lot of punch. Technics 207C w/Jico SAS, Signet TK-7lca and Shelter 201 w/Jico SAS are also winners.

 

 

The big difference between MC/MI/and MM cartridges boils down to a very few factors, most notably stylus profile, of which much ink has been spilled, and inductance, which is rarely mentioned. Moving coil carts have the lowest, then Moving Iron, and then Moving Magnet. why does this matter? Inductance directly relates to a property called hysteresis, the delay between a change in input and a change in output. Google 'hysteresis curve' and you'll see the characteristic 'S' shaped hysteresis curve, and its return, the hysteresis loop. Ultra low output MCs sound fast and detailed in large because they have low inductance, thus low hysteresis. MI carts like Grado and Soundsmith  have greater inductance, roughly in the 50mH range, but the difference is incremental. Most Moving Magnet carts have 10X more inductance around 450-550 mH and accordingly 10X more hysteresis, more delay between changes in input (stylus motion) and a change in output voltage. They simply cannot respond without 'smearing'. The tradeoff in general is output voltage, where MM carts win by a mile, thus making preamp design easier and more forgiving. This is why most MC carts require an additional level of gain, and usually worse S/N ratios. There are other factors, to be sure, vibration control, compliance, tracking ability, and several more but all of those can be controlled independently of the electromagnetic performance of the generator which is determined in large by the cartridge designers choice of MC, MI, or MM. I haven't gone into cartridge loading which is important, but cannot compensate for the hysteresis inherent in the design.

The Nagaoka MP-500 is the closest sounding cartridge to my London Decca Reference. I have bought a couple of spare styli for it, plus a tonearm to mount it on. It's that good, and clearly beats the Grado Statement 3 and the SoundSmith Sussurro MkII. I do run a table with two MC cartridges (Ortofon Cadenza Bronze and Mono) as well, but they come behind the MP-500 for musicality.

Jason, kudos to your friend with the Marantz-Futterman-Quad system. That’s a vintage combination to rival many modern high end systems except it needs a subwoofer. Back in the early 70s, I owned a similar system save for using KLH9s, first one pair and eventually two pairs, in lieu of the Quads.

Soundsmith makes a strain-gauge cartridge. This type does not use an RIAA network/phono stage. It does the equalization mechanically. It can drive a line stage - eliminating the phono stage. I listened to the Panasonic strain gauge at a friend's house. It fed the line stage of a Marantz 7 tube preamp into a pair of Futterman H3aa OTL amps into Quad 57's. I was impressed! Soundsmith claims their strain gauge cartridge is a superior improvement over the Panasonic.

Nagaoka MP500 is about as good as it gets IMHO, but it’s subjective and very system dependent. It does a lot of things extremely well, and doesn't have any bad habits.  Technically it’s moving permalloy, but I wouldn’t let semantics be the reason to stop you from trying it. 😎

I remain an mc cartridge fan and user because no mm or mi type I have tried can equal the "liveliness" and detail retrieval of a good mc cartridge. Even the lowly Denon 103 is capable of astonishing sound quality! Why don't you consider an upper-tier mc cartridge like a Miyajima Madake? After all, that Ortofon SPU is rather long-in-the-tooth for an mc design!

I went through that phase just recently. I have owned Grados and Clearaudios, but the best so far overall was the Soundsmith Voice. It punches way above it's price point with exceptional tracking and remarkable neutrality. I gave it to a friend for his birthday and he greatly prefers it to his old Spectral (really a Lyra) cartridge. My current phono stage will not handle a high output cartridge.

Way back in the Days of Yore (late 70's) I had to choose between two cartridges - an MC and an MI type. The GAS Sleeping Beauty and the Grado Signature One. Both cost the same - $240. I went with the Sleeping Beauty mc cartridge - though I had to put it aside for a few months until I could afford a Mitchell Cotter SUT. The Sleeping Beauty gave much pleasure, though the Signature One would have probably served just as well! I just didn't want to pay so much for a Grado cartridge. The lowly Grado FTE ($15!) was praised by Harry Pearson. The Signature One ($240) was Grado's premium - and most expensive! - cartridge. I shake my head in disbelief when I read of a Grado Epoch costing $12K! 

The Grado is a safe bet! You will have to buy it and try it in your own system. Too many variables in other users’ systems to depend upon anecdotal opinions. Cartridges, like speakers, vary widely in sound quality. What pleases someone else may not please you!