Who needs a MM cartridge type when we have MC?


Dear friends: who really needs an MM type phono cartridge?, well I will try to share/explain with you what are my experiences about and I hope too that many of you could enrich the topic/subject with your own experiences.

For some years ( in this forum ) and time to time I posted that the MM type cartridge quality sound is better than we know or that we think and like four months ago I start a thread about: http://forum.audiogon.com/cgi-bin/fr.pl?eanlg&1173550723&openusid&zzRauliruegas&4&5#Rauliruegas where we analyse some MM type cartridges.

Well, in the last 10-12 months I buy something like 30+ different MM type phono cartridges ( you can read in my virtual system which ones. ) and I’m still doing it. The purpose of this fact ( “ buy it “ ) is for one way to confirm or not if really those MM type cartridges are good for us ( music lovers ) and at the same time learn about MM vs MC cartridges, as a fact I learn many things other than MM/MC cartridge subject.

If we take a look to the Agon analog members at least 90% of them use ( only ) MC phono cartridges, if we take a look to the “ professional reviewers “ ( TAS, Stereophile, Positive Feedback, Enjoy the Music, etc, etc, ) 95% ( at least ) of them use only MC cartridges ( well I know that for example: REG and NG of TAS and RJR of Stereophile use only MM type cartridges!!!!!!!! ) , if we take a look to the phono cartridge manufacturers more than 90% of them build/design for MC cartridges and if you speak with audio dealers almost all will tell you that the MC cartridges is the way to go.

So, who are wrong/right, the few ( like me ) that speak that the MM type is a very good alternative or the “ whole “ cartridge industry that think and support the MC cartridge only valid alternative?

IMHO I think that both groups are not totally wrong/right and that the subject is not who is wrong/right but that the subject is : KNOW-HOW or NON KNOW-HOW about.

Many years ago when I was introduced to the “ high end “ the cartridges were almost MM type ones: Shure, Stanton, Pickering, Empire, etc, etc. In those time I remember that one dealer told me that if I really want to be nearest to the music I have to buy the Empire 4000 D ( they say for 4-channel reproduction as well. ) and this was truly my first encounter with a “ high end cartridge “, I buy the 4000D I for 70.00 dls ( I can’t pay 150.00 for the D III. ), btw the specs of these Empire cartridges were impressive even today, look: frequency response: 5-50,000Hz, channel separation: 35db, tracking force range: 0.25grs to 1.25grs!!!!!!!!, just impressive, but there are some cartridges which frequency response goes to 100,000Hz!!!!!!!!!!

I start to learn about and I follow to buying other MM type cartridges ( in those times I never imagine nothing about MC cartridges: I don’t imagine of its existence!!!. ) like AKG, Micro Acoustics, ADC, B&O, Audio Technica, Sonus, etc, etc.

Years latter the same dealer told me about the MC marvelous cartridges and he introduce me to the Denon-103 following with the 103-D and the Fulton High performance, so I start to buy and hear MC cartridges. I start to read audio magazines about either cartridge type: MM and Mc ones.

I have to make changes in my audio system ( because of the low output of the MC cartridges and because I was learning how to improve the performance of my audio system ) and I follow what the reviewers/audio dealers “ speak “ about, I was un-experienced !!!!!!!, I was learning ( well I’m yet. ).

I can tell you many good/bad histories about but I don’t want that the thread was/is boring for you, so please let me tell you what I learn and where I’m standing today about:

over the years I invested thousands of dollars on several top “ high end “ MC cartridges, from the Sumiko Celebration passing for Lyras, Koetsu, Van denHul, to Allaerts ones ( just name it and I can tell that I own or owned. ), what I already invest on MC cartridges represent almost 70-80% price of my audio system.

Suddenly I stop buying MC cartridges and decide to start again with some of the MM type cartridges that I already own and what I heard motivate me to start the search for more of those “ hidden jewels “ that are ( here and now ) the MM phono cartridges and learn why are so good and how to obtain its best quality sound reproduction ( as a fact I learn many things other than MM cartridge about. ).

I don’t start this “ finding “ like a contest between MC and MM type cartridges.
The MC cartridges are as good as we already know and this is not the subject here, the subject is about MM type quality performance and how achieve the best with those cartridges.

First than all I try to identify and understand the most important characteristics ( and what they “ means “. ) of the MM type cartridges ( something that in part I already have it because our phonolinepreamp design needs. ) and its differences with the MC ones.

Well, first than all is that are high output cartridges, very high compliance ones ( 50cu is not rare. ), low or very low tracking force ones, likes 47kOhms and up, susceptible to some capacitance changes, user stylus replacement, sometimes we can use a different replacement stylus making an improvement with out the necessity to buy the next top model in the cartridge line , low and very low weight cartridges, almost all of them are build of plastic material with aluminum cantilever and with eliptical or “ old “ line contact stylus ( shibata ) ( here we don’t find: Jade/Coral/Titanium/etc, bodies or sophisticated build material cantilevers and sophisticated stylus shape. ), very very… what I say? Extremely low prices from 40.00 to 300.00 dls!!!!!!!!!!!!!!!!!!, well one of my cartridges I buy it for 8.99 dls ( one month ago ): WOW!!!!!!, so any one of you can/could have/buy ten to twenty MM cartridges for the price of one of the MC cartridge you own today and the good notice is that is a chance that those 10-20 MM type cartridges even the quality performance of your MC cartridge or beat it.

Other characteristics is that the builders show how proud they were/are on its MM type cartridges design, almost all those cartridges comes with a first rate box, comes with charts/diagrams of its frequency response and cartridge channel separation ( where they tell us which test recording use it, with which VTF, at which temperature, etc, etc. ), comes with a very wide explanation of the why’s and how’s of its design and the usual explanation to mount the cartridge along with a very wide list of specifications ( that were the envy of any of today MC ones where sometimes we really don’t know nothing about. ), comes with a set of screws/nuts, comes with a stylus brush and even with stylus cleaning fluid!!!!!!!!!, my GOD. Well, there are cartridges like the Supex SM 100MK2 that comes with two different stylus!!!! One with spherical and one with elliptical/shibata shape and dear friends all those in the same low low price!!!!!!!!!!!

Almost all the cartridges I own you can find it through Ebay and Agon and through cartridge dealers and don’t worry if you loose/broke the stylus cartridge or you find the cartridge but with out stylus, you always can/could find the stylus replacement, no problem about there are some stylus and cartridge sources.

When I’m talking about MM type cartridges I’m refer to different types: moving magnet, moving iron, moving flux, electret, variable reluctance, induced magnet, etc, etc. ( here is not the place to explain the differences on all those MM type cartridges. Maybe on other future thread. ).

I made all my very long ( time consuming ) cartridge tests using four different TT’s: Acoustic Signature Analog One MK2, Micro Seiki RX-5000, Luxman PD 310 and Technics SP-10 MK2, I use only removable headshell S and J shape tonearms with 15mm on overhang, I use different material build/ shape design /weight headshells. I test each cartridge in at least three different tonearms and some times in 3-4 different headshells till I find the “ right “ match where the cartridge perform the best, no I’m not saying that I already finish or that I already find the “ perfect “ match: cartridge/headshell/tonearm but I think I’m near that ideal target.

Through my testing experience I learn/ confirm that trying to find the right tonearm/headshell for any cartridge is well worth the effort and more important that be changing the TT. When I switch from a TT to another different one the changes on the quality cartridge performance were/are minimal in comparison to a change in the tonearm/headshell, this fact was consistent with any of those cartridges including MC ones.

So after the Phonolinepreamplifier IMHO the tonearm/headshell match for any cartridge is the more important subject, it is so important and complex that in the same tonearm ( with the same headshell wires ) but with different headshell ( even when the headshell weight were the same ) shape or build material headshell the quality cartridge performance can/could be way different.

All those experiences told me that chances are that the cartridge that you own ( MC or MM ) is not performing at its best because chances are that the tonearm you own is not the best match for that cartridge!!!!!!, so imagine what do you can/could hear when your cartridge is or will be on the right tonearm???!!!!!!!!, IMHO there are ( till today ) no single ( any type at any price ) perfect universal tonearm. IMHO there is no “ the best tonearm “, what exist or could exist is a “ best tonearm match for “ that “ cartridge “, but that’s all. Of course that are “ lucky “ tonearms that are very good match for more than one cartridge but don’t for every single cartridge.

I posted several times that I’m not a tonearm collector, that I own all those tonearms to have alternatives for my cartridges and with removable headshells my 15 tonearms are really like 100+ tonearms : a very wide options/alternatives for almost any cartridge!!!!!!

You can find several of these MM type cartridges new brand or NOS like: Ortofon, Nagaoka, Audio Technica, Astatic, B&O, Rega, Empire, Sonus Reson,Goldring,Clearaudio, Grado, Shelter, Garrot, etc. and all of them second hand in very good operational condition. As a fact I buy two and even three cartridges of the same model in some of the cartridges ( so right now I have some samples that I think I don’t use any more. ) to prevent that one of them arrive in non operational condition but I’m glad to say that all them arrive in very fine conditions. I buy one or two of the cartridges with no stylus or with the stylus out of work but I don’t have any trouble because I could find the stylus replacement on different sources and in some case the original new replacement.

All these buy/find cartridges was very time consuming and we have to have a lot of patience and a little lucky to obtain what we are looking for but I can asure you that is worth of it.

Ok, I think it is time to share my performance cartridge findings:

first we have to have a Phonolinepreamplifier with a very good MM phono stage ( at least at the same level that the MC stage. ). I’m lucky because my Phonolinepreamplifier has two independent phono stages, one for the MM and one for MC: both were designed for the specifics needs of each cartridge type, MM or MC that have different needs.

we need a decent TT and decent tonearm.

we have to load the MM cartridges not at 47K but at 100K ( at least 75K not less. ).

I find that using 47K ( a standard manufacture recommendation ) prevent to obtain the best quality performance, 100K make the difference. I try this with all those MM type cartridges and in all of them I achieve the best performance with 100K load impedance.

I find too that using the manufacturer capacitance advise not always is for the better, till “ the end of the day “ I find that between 100-150pf ( total capacitance including cable capacitance. ) all the cartridges performs at its best.

I start to change the load impedance on MM cartridges like a synonymous that what many of us made with MC cartridges where we try with different load impedance values, latter I read on the Empire 4000 DIII that the precise load impedance must be 100kOhms and in a white paper of some Grace F9 tests the used impedance value was 100kOhms, the same that I read on other operational MM cartridge manual and my ears tell/told me that 100kOhms is “ the value “.

Before I go on I want to remember you that several of those MM type cartridges ( almost all ) were build more than 30+ years ago!!!!!!!! and today performs at the same top quality level than today MC/MM top quality cartridges!!!!!, any brand at any price and in some ways beat it.

I use 4-5 recordings that I know very well and that give me the right answers to know that any cartridge is performing at its best or near it. Many times what I heard through those recordings were fine: everything were on target however the music don’t come “ alive “ don’t “ tell me “ nothing, I was not feeling the emotion that the music can communicate. In those cartridge cases I have to try it in other tonearm and/or with a different headshell till the “ feelings comes “ and only when this was achieved I then was satisfied.

All the tests were made with a volume level ( SPL ) where the recording “ shines “ and comes alive like in a live event. Sometimes changing the volume level by 1-1.5 db fixed everything.

Of course that the people that in a regular manner attend to hear/heard live music it will be more easy to know when something is right or wrong.

Well, Raul go on!!: one characteristic on the MM cartridges set-up was that almost all them likes to ride with a positive ( little/small ) VTA only the Grace Ruby and F9E and Sonus Gold Blue likes a negative VTA , on the other hand with the Nagaoka MP 50 Super and the Ortofon’s I use a flat VTA.

Regarding the VTF I use the manufacturer advise and sometimes 0.1+grs.
Of course that I made fine tuning through moderate changes in the Azymuth and for anti-skate I use between half/third VTF value.

I use different material build headshells: aluminum, composite aluminum, magnesium, composite magnesium, ceramic, wood and non magnetic stainless steel, these cartridges comes from Audio Technica, Denon, SAEC, Technics, Fidelity Research, Belldream, Grace, Nagaoka, Koetsu, Dynavector and Audiocraft.
All of them but the wood made ( the wood does not likes to any cartridge. ) very good job . It is here where a cartridge could seems good or very good depending of the headshell where is mounted and the tonearm.
Example, I have hard time with some of those cartridge like the Audio Technica AT 20SS where its performance was on the bright sound that sometimes was harsh till I find that the ceramic headshell was/is the right match now this cartridge perform beautiful, something similar happen with the Nagaoka ( Jeweltone in Japan ), Shelter , Grace, Garrot , AKG and B&O but when were mounted in the right headshell/tonearm all them performs great.

Other things that you have to know: I use two different cooper headshell wires, both very neutral and with similar “ sound “ and I use three different phono cables, all three very neutral too with some differences on the sound performance but nothing that “ makes the difference “ on the quality sound of any of my cartridges, either MM or MC, btw I know extremely well those phono cables: Analysis Plus, Harmonic Technologies and Kimber Kable ( all three the silver models. ), finally and don’t less important is that those phono cables were wired in balanced way to take advantage of my Phonolinepreamp fully balanced design.

What do you note the first time you put your MM cartridge on the record?, well a total absence of noise/hum or the like that you have through your MC cartridges ( and that is not a cartridge problem but a Phonolinepreamp problem due to the low output of the MC cartridges. ), a dead silent black ( beautiful ) soundstage where appear the MUSIC performance, this experience alone is worth it.

The second and maybe the most important MM cartridge characteristic is that you hear/heard the MUSIC flow/run extremely “ easy “ with no distracting sound distortions/artifacts ( I can’t explain exactly this very important subject but it is wonderful ) even you can hear/heard “ sounds/notes “ that you never before heard it and you even don’t know exist on the recording: what a experience!!!!!!!!!!!

IMHO I think that the MUSIC run so easily through a MM cartridge due ( between other facts ) to its very high compliance characteristic on almost any MM cartridge.

This very high compliance permit ( between other things like be less sensitive to out-center hole records. ) to these cartridges stay always in contact with the groove and never loose that groove contact not even on the grooves that were recorded at very high velocity, something that a low/medium cartridge compliance can’t achieve, due to this low/medium compliance characteristic the MC cartridges loose ( time to time and depending of the recorded velocity ) groove contact ( minute extremely minute loose contact, but exist. ) and the quality sound performance suffer about and we can hear it, the same pass with the MC cartridges when are playing the inner grooves on a record instead the very high compliance MM cartridges because has better tracking drive perform better than the MC ones at inner record grooves and here too we can hear it.

Btw, some Agoners ask very worried ( on more than one Agon thread ) that its cartridge can’t track ( clean ) the cannons on the 1812 Telarc recording and usually the answers that different people posted were something like this: “””” don’t worry about other than that Telarc recording no other commercial recording comes recorded at that so high velocity, if you don’t have trouble with other of your LP’s then stay calm. “””””

Well, this standard answer have some “ sense “ but the people ( like me ) that already has/have the experience to hear/heard a MM or MC ( like the Ortofon MC 2000 or the Denon DS1, high compliance Mc cartridges. ) cartridge that pass easily the 1812 Telarc test can tell us that those cartridges make a huge difference in the quality sound reproduction of any “ normal “ recording, so it is more important that what we think to have a better cartridge tracking groove drive!!!!

There are many facts around the MM cartridge subject but till we try it in the right set-up it will be ( for some people ) difficult to understand “ those beauties “. Something that I admire on the MM cartridges is how ( almost all of them ) they handle the frequency extremes: the low bass with the right pitch/heft/tight/vivid with no colorations of the kind “ organic !!” that many non know-how people speak about, the highs neutral/open/transparent/airy believable like the live music, these frequency extremes handle make that the MUSIC flow in our minds to wake up our feelings/emotions that at “ the end of the day “ is all what a music lover is looking for.
These not means that these cartridges don’t shine on the midrange because they do too and they have very good soundstage but here is more system/room dependent.

Well we have a very good alternative on the ( very low price ) MM type cartridges to achieve that music target and I’m not saying that you change your MC cartridge for a MM one: NO, what I’m trying to tell you is that it is worth to have ( as many you can buy/find ) the MM type cartridges along your MC ones

I want to tell you that I can live happy with any of those MM cartridges and I’m not saying with this that all of them perform at the same quality level NO!! what I’m saying is that all of them are very good performers, all of them approach you nearest to the music.

If you ask me which one is the best I can tell you that this will be a very hard “ call “ an almost impossible to decide, I think that I can make a difference between the very good ones and the stellar ones where IMHO the next cartridges belongs to this group:

Audio Technica ATML 170 and 180 OCC, Grado The Amber Tribute, Grace Ruby, Garrot P77, Nagaoka MP-50 Super, B&O MMC2 and MMC20CL, AKG P8ES SuperNova, Reson Reca ,Astatic MF-100 and Stanton LZS 981.

There are other ones that are really near this group: ADC Astrion, Supex MF-100 MK2, Micro Acoustics MA630/830, Empire 750 LTD and 600LAC, Sonus Dimension 5, Astatic MF-200 and 300 and the Acutex 320III.

The other ones are very good too but less refined ones.
I try too ( owned or borrowed for a friend ) the Shure IV and VMR, Music maker 2-3 and Clearaudio Virtuoso/Maestro, from these I could recommended only the Clearaudios the Shure’s and Music Maker are almost mediocre ones performers.
I forgot I try to the B&O Soundsmith versions, well this cartridges are good but are different from the original B&O ( that I prefer. ) due that the Sounsmith ones use ruby cantilevers instead the original B&O sapphire ones that for what I tested sounds more natural and less hi-fi like the ruby ones.

What I learn other that the importance on the quality sound reproduction through MM type cartridges?, well that unfortunately the advance in the design looking for a better quality cartridge performers advance almost nothing either on MM and MC cartridges.

Yes, today we have different/advanced body cartridge materials, different cantilever build materials, different stylus shape/profile, different, different,,,,different, but the quality sound reproduction is almost the same with cartridges build 30+ years ago and this is a fact. The same occur with TT’s and tonearms. Is sad to speak in this way but it is what we have today. Please, I’m not saying that some cartridges designs don’t grow up because they did it, example: Koetsu they today Koetsu’s are better performers that the old ones but against other cartridges the Koetsu ones don’t advance and many old and today cartridges MM/MC beat them easily.

Where I think the audio industry grow-up for the better are in electronic audio items ( like the Phonolinepreamps ), speakers and room treatment, but this is only my HO.

I know that there are many things that I forgot and many other things that we have to think about but what you can read here is IMHO a good point to start.

Regards and enjoy the music.
Raul.
Ag insider logo xs@2xrauliruegas
Dear Raul,
I can't really follow your explanation why longer arms should produce more distortion. maybe you can explain this is in short if you like.
I am a bit puzzled hearing from you that the rewiring of your SAEC arms did not lead to good results. We will be not able to find out what was the reason herefore in your system but I can tell you from my experience if it is well done it is a big difference and not one with more distortion - not at all. Maybe you should try again - just a suggestion.

Best & Fun Only
This is an interesting topic...
T_Bone - with regards to item 1) Lower moment of inertia with near zero friction...
Isn't that exactly what was being aimed for in the best arms of the late 70's and early 80's? The High Compliance is King era?
Like everything in analogue perfection is impossible - but there were (are) arms that achieve effective mass of under 6g... and a number that achieve around or under 4g. - I would assume that along with an effective mass of that level will come a much lower moment of inertia.

Lower bearing stiction I agree with - but lower friction not necessarily as a level of damping is valuable in assisting the control of the arm/cartridge resonances - it does need to be the right kind of friction.

And this is where we come up with the theoretical impossibilities - best from one perspective is zero friction, but achieving that will exacerbate another aspect (arm/cartridge resonance) so you either design some friction into the system or you design it as a minimum friction system and then attach an artificial friction system (fluid/servo damping).

With regards to a longer arm... the resonant frequencies will be altered - so differing arm damping solutions will be required - the more damping is applied (and I am talking HF damping rather than the LF fluid damping) - the more mass is added to the arm. - Another case where the gain of reduced tracking error through arm length needs to be balanced with increased mass which causes a different set of issues.

You can of course balance the increased mass with lowered compliance - but then you tend to also lower tracking ability at lower frequencies (more swings and roundabouts!)

I hate to say it but the vinyl world was, in the early 80's, racing towards linear tracking systems.... only to hit the brick wall of digital. The funding for R&D dried up overnight, leaving boutique development (which has not ceased, but rate of change/progress is very very low)
a) With linear tracking angular tracking error becomes a non issue.
b) with linear tracking the arm length can be minimal and therefore the arm mass can be reduced (eg: Revox Linatrack... the headshell is the arm!). Keeping in mind that a linear tracking arm transport can pivot or be positioned to travel directly over the record surface (like the many clamshell TT's with the arm in the lid, or the Revox) allowing vestigial arms.
Many current linear trackers have long(er) arms (and therefore higher mass) due to the arm tracking system residing off the record.

If we are talking about the ideal arm for some of the sophisticated cartridge - and aiming for high tracking capabilities, etc....
Why are we talking about prehistoric pivoted arm designs (flame proof armor activated...). Yes, crocodiles are a successful prehistoric dinosaur that survives to this day... but I'll take a predatory mammal as my preferred and more advanced/evolved choice. (and yes I know I am playing very loose with evolutionary concepts.... it's just a metaphor playing on common evolutionary mythology of linear "progress")

Why not instead discuss the ways to select, design, build or optimise a linear tracking arm - it is a better starting point ultimately for a perfect design.

Also the patents for all the great linear tracking arms of the 70's and 80's have all expired - all this technology is sitting out there begging for someone to use it!
And some of these patents include designs for systems that were never commercialised - and which were too difficult to commercialise without advanced digital control systems - which are now very economical.
eg: JVC patented a method of correcting for record centering (a la Nakamichi Dragon CT) - but using platter speed control in combination with arm mounted sensors... (ok not a directly relevant "arm" example, and it would require a very special kind of platter drive, with very precise speed control and perhaps a lower mass platter for rapid response - an interesting engineering approach which went off on a complete tangent from everything else....fascinating!!)
Revox had an electro-magnetic arm servo damping system described and patented for the Linatrack arm - never produced.
And there are the Linear tracking Sony biotracers - all that complex circuitry would now be built into a couple of digital control chips - making it simple and economical...
etc...

I look at this and I think that the whole discussion is talking about how to improve a dinosaur - a very effective dinosaur - but we have better starting points today than were common in the 70's.

bye for now

David
Hi T_bone, When most of us conceptualize tracking we probably think of the cartridge (tip) in two dimensions at a time. In reality tracking is three dimensional. The cartridge and arm are constantly moving both horizontally and vertically. Thinking only in terms of compliance (springiness) is not adequate for understanding.

***This is, as far as I can tell (from my completely non-AHEE and still layman physics education about turntable/tonearm/cart/cantilever/stylus/groove physics), completely wrong. If the theory were right, then the ultimate tonearm would have zero mass and zero bearing friction. This would leave us with no music.***

No one is talking about the "ultimate" tonearm. It doesn't exist. Within the confines of real world record playing there are advantages and disadvantages with longer arms. The advantages are slightly lower tracking angle error and reduced SRA/VTA differences with warps. The disadvantage is worse MOI. I'm sure you're aware of the advantage of an underslung counterweight with arms that have bearings above the plane of the record. Arm length can be seen as part of the same thing. There is an increased time constant between bearings and stylus with longer arms.
Regards,
I stipulate the following points and conditions:
1) there is no PERFECT arm.
2) Some arms are better than others (they introduce less distortion into a system) with a given cart.
3) when discussing a 'better' design WITHOUT KEEPING OTHER FACTORS CONSTANT (such as cart or cart compliance) I assume it is universally better, not just better with a fixed compliance.
4) All discussions assume the record is flat and not off-center.

Dear Raul and Fleib,
I did not mention the 'third dimension' because I thought it obvious. Styli move up and down and left and right. Tonearm pivots do too. Assuming the record is perfectly flat AND the record is perfectly-centered, the reason why tonearm pivots MUST move from side to side is to track from outer groove to inner groove. The reason why they MUST move up and down is because the record is cued up and down. Carts have both vertical and horizontal compliance. Compliance is a force. Music is neither constant in frequency nor amplitude so the cantilever applies all kinds of fast-moving forces at the cantilever pivot. That's the point. Nobody has yet explained why the stylus end of the tonearm is SUPPOSED to move WITH the stylus. If it does, a 'better' tonearm (one which most closely approximates perfect even though there is no perfect) will move with the same speed as the stylus will. This means the cantilever/magnet/coil is not moving in relation to the body/coil/magnet. This means no music.

Raul,
Regarding my 3rd point, I think discussion of length of tonearm wire as different than changing headshell wires and observing a difference. The 'improvement' of shortening a tonearm from 12" to 9" in order to shorten the length of wire that a tiny wire passes through is just as easily accomplished by shortening the phono cord at the RCA end. I do not think that the tonearm-shortening effort has a measurable impact on signal accuracy because of less wire.

Fleib,
I understand the underslung counterweight. I do not see the connection with arm length. I see the potential that longer arms have a higher MOI. I have not heard/seen any answer yet as to why a higher MOI is NECESSARILY bad.

David,
This DOES get interesting. Just because 'high-compliance-is-king' existed does not mean that it actually was theoretically better. And the fact that we now start talking about levels of compliance - i.e. levels of force - in combination with lower levels of arm effective mass means we can also say that lower compliance necessitates higher MOI.

Your idea of 'encouraging' some level of friction vs stiction in order to counter resonance, or using fluid damping, is all an effort to provide an 'increase' in force countering the forces applied on the tonearm by the forces applied by the cantilever on the cantilever pivot point where it 'meets' the cart body. They are all raising "Effective MOI." This goes to my point above, that tonearm designers/users will seek to control resonance a variety of ways. Chief among those will be correct matching of forces (i.e. APPROPRIATE MOI, not LOWEST POSSIBLE MOI).

I understand why some people say low compliance carts track badly. I view it as the fact they have not used the appropriate arm. I do not find my lowest compliance carts track particularly badly.

Regarding your point (b) on linear tracking arms.... Assuming the arm length is as short as the headshell (which is mounted on a linear bar/rail/trough/air bearing), how does one set appropriate MOI assuming an EXTREMELY low lateral friction? Does one want the lowest possible MOI? The highest? Or the appropriate amount to counter cantilever force on the bearing connection? One certainly does not want the lowest possible weight of cart body with lowest possible friction with a cantilever compliance lower than the highest humanly possible.

Have I got this all wrong? Should my beloved FR-7f be cracked open like a lobster, mounted on a balsa shell and mounted on my AT1100 with a gold nugget stuck on the counterweight?
Dear Fleib,
I am not sure what you mean by 'time constant between bearing and stylus'. Is it measurable or definable in any way? The headshell of a long arm takes exactly the same time to move from outer groove to inner groove as the headshell on a short, low MOI, arm.