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 Ddriveman: Well I had not problems like the one you had with the MMC2, I buyed several second hand cartridges and was lucky not to claim for any one.

Now, it is suppose that ruby and sapphire ( the one in the MMC2 cantilever. ) has similar characteristics so more than the differences in the B&O and Sounsmith build material cantilevers the real differences are in the Soundsmith cartridge voicing that IMHO is tamed on the hi-fi side against a more natural performance in the B&O, yes I prefer the B&O.

Regards and enjoy the music,
Raul.
Dear Raul, You wrote, "Dear Downunder: Normally as you go higher on capacitance as the cartridge goes brighther."

As I see it, the capacitances of the phono stage and the interconnect, etc, are all in parallel with the signal voltage. Since the impedance of any capacitor goes down as frequency goes up, I would also expect more of the signal voltage to be shunted to ground via the capacitance, as frequency goes up. Therefore, I would have predicted the opposite of what you state, the sound should get a bit duller as the hf is progressively shunted to ground, assuming the load R is held constant. Can you or anyone point out the flaw in my thinking? Thanks. I realize my hypothesis may run counter to your listening experience; sometimes life is like that.
Lewm,
Raul is absolutely correct in what he states - but of course for MM only!
As far as MCs are concerened it is the other way 'round and follows your argument.

Axel
PS: The clue is the *much* higher impedance of MMs.
Raul, I don't believe you are correct re the phono capacitance. As Lewm has stated, the sound is supposed to get less bright as you add cap pf.

I have pf adjustment on the remote control of my Mac MM phono stage and as you go up in pf the treble gets less bright and more natural, until you reach a value and it then starts to roll off.

If you read M Fremer's review on the Soundsmith Voice cart a few mnths back - he categorically stated that since the Soundsmith carts were loaded for 400pf, if you use 100 or 200 pf at your phono stage, it would sound bright.
Lederman confirmed as such and stated that all his MM carts were now loaded to a more normal 150 or 200 pf if I remember correctly.

the Empire 1080LT specifically states in the specs that it is loaded at 300pf. I noticed that it was bright and a little lean in tone loaded at 100 or 150pf, but "just right" loaded at the recommended 300pf in my system. 250pf is pretty good as well.
Perhaps why some might have found the 1080LT or Soundsmith carts bright or hifi sounding is due to incorrect pf loading at lower than 300 and 400 respectively

cheers
Woe is me. My Empire is a 1000ZE, not a ZE/X. My Ortofon is an M50FL Super, not an M50E. This reminds me of Janis Joplin's lament:
"Oh Lord, won't you buy me
a Mercedes-Benz
My friends all have Porsches
I must make amends"....

I saw a very interesting discussion on one of these websites of how the brain works to seek out and devour the new in favor of the familiar. Someone has written a book about it. There's nothing to prevent it, but to account for the phenomenon, I think we have to take a longer time to evaluate these items, and then, once one is familiar with the new, go back to the old or the most recent previously preferred sample, to see if the new obsession really holds up.
... And to know that place for the first time

Dgarretson,

I've been experimenting with my MF100 on a modified magnesium headshell and silver leads. It is even better than I had initially recognised. A joyous cartridge.

I'm having a similar experience with my B&O MMC2 on a green dot Morch DP6. Making these two of my most convincing and enjoyable cartridges.
Lewm,
you got the Porscheee, and the Merc - it's just a question of the best tyres, hm.
BTW, there is a re-vamp version for 1/2 price for that M20E stylus at LP-Gear.
I got mine in the Ortofon original package (by that german source) and that is $99... I have no idea about that E "after-market" version's quality performance but from the little experience I have this far, I'd go for the real thing.
That "E" is it! as far as I can tell, and as I mentioned it will stay so for some time.
Greetings,
Axel
Dear Axelwahl: I agree with you about the 20E quality performance and its status over other cartridges but the Empire ZE/X.

All our audio systems has its own " limitations " that one way or the other when we approach/near that " limitations " the discerning on different items quality performance be more and more dificult to attain/achieve in a very clear and precise way.

That Empire cartridge as great as is it is a little " reticent " ( more than other cartridges. ) to show is greatness if the conditions are not the " ideal " one (near. ).
One of that " ideal " condition is the tonearm. I know very well your SME one and IMHO it is not the best match to the Empire due to that little/tiny dark side coloration that the SME has and that coincide with the Empire " reticent " on the highs.

I rank the ZE/X on 9 level after test it in three different tonearms with two different headshells till I find out its " greatness ".

The 20E is really good an IMHO a very solid top 6 level but I just can't think on level 7 for the 20E because today I have at least two other cartridges ( Astatic MF-100 and B&O MMC2. ) that IMHO are or perform a little better.

Axel, this is not " big deal " because all of us know that these subjective experiences are system dependent and the system differences on each one of us makes that sometime with a specific cartridge we can't coincide at 100%.

Anyway, the fun goes on!

Regards and enjoy the music,
Raul.
Axel, It cannot possibly be the case that the effect of a parallel capacitance is opposite for MCs vs MMs. The mechanism by which a capacitance in parallel with the signal could tend to roll off high frequencies applies to either type. But other factors, such as the values of load resistance, and the cartridges internal resistance and inductance could tend to push the roll off effect up out of the relevant audio bandwidth. For example, most people (not all) would agree that a roll-off above 50kHz or 100kHz is entirely acceptable. So because of those factors, cable and input capacitance may be less worrisome for one type vs the other. (This is my considered opinion based on what I think I know. Since I am an amateur in this field, I stand ready to be corrected.)
Regards, all: (Long) Interesting communications. As to capacitance (and loading), to quote Pioneer Electronics: "Typical moving magnet (MM) cartridges have resonance peaks at high frequencies. However the height of the peaks can be varied by changing the load resistance (k Ohm). The peaks increase as the resistance is increased. In addition, the resonance frequency (center of the peak frequency) can be varied by changing the load capacitance (pF). If the capacitance is increased, then the resonance frequency is lowered (bell curve moves to the left) and the peaks are increased." Essentially as loading is increased, high frequencies are emphasised. Raising capacitance results in resonance at the center of these peaks being increased, having the effect of brightening the upper midrange.

This somehow leads to Rauls' statements regarding the matrix of tonearm/headshell/etc. As set and setting are a variable, cartridge loading and capacitance can be a factor in matching a system to the acoustic enviornment. One manufacturor's anechoic chamber may give measurably different outcomes than the next. Consequently, careful design and calibration resulting in system synergy and meeting the requirments of a specific enviornment is as important as the performance of any individual component. In the seventies, there was much knowledgable discussion of equalizing for flat response. This in pursuit of excellence and never a justification for accepting mediocrity. At the user end of this technology, I let my ears be my guide.

Apologies if you think I've elaborated on the obvious or trivialized the momentious. If Axel enjoys his Porche M20E or someone else the Mercedes ZE/X Black, its all good, but I say the Grace F9E is the Bugatti Valeron of MM cartridges.
Well, thanks Timtel, you put it pretty well and with regards to Lewm's question in deed (I hope he can agree by now!)

I also go along with Raul's tonearm/head-shell related experience.
In the SME V this M20E is just the most "balanced", "integrated" cart I heard to date. It has the most beautiful treble resolution heard with cymbals and the like, as well as the best width and depth to boot and in no way less (rather more) then the FL. The bass is also more tight, very similar to the MP-50's.
This creates the listening impression of more dynamics (faster transients) most noticeably by comparison with the ZE/X which sounds somewhat layed-back by comparison.
The "speed" of the "E" is that of the MP-50 yet it sounds less "jumped-up" (MC like) in the treble.
Is it back to boron cantilever behaviour for the MP-50 ?
It be interesting to hear an alu (or beryllium) tube cantilever MC just to see whether this is more then just coincident.
The only such item I know: the Blue Angel Mantis MC, the listening feedbacks seem to point in this direction also.
Greetings,
Axel
MM capacitance - again matches up with my listening

http://www.soundfountain.com/amb/ttcartridge.html

" The capacitance of the input of the amplifier should more or less match the value of the cartridge.
Of course a lot of scientific explanation can be given. In this respect mathematics and algebra are there for the technical buff. Just follow this rule:
The higher the capacitive value of the input the duller the sound will be. The lower the capacitance the brighter the sound gets. A mismatch results either in dark dull sound or an overbright, distorted signal. "

TNT audio and capacitance measurements on a nagaoka MP-11

http://www.tnt-audio.com/sorgenti/nagaoka_mp11_e.html

Stereophile Nov 09 - Fremer review of Sounsmith Voice

" When Soundsmith recommend 400pf or greater, they mean it. Cables will add some capacitance, but if your phono capacitance loading is fixed at say 200pf, you'll get a bright sound"
Soundsmith manufacturer comments - " Michaels comments on capacitive loadings are consistent with feedback from our customers, so now all moving iron cartridges are sold as internally compensated for a standard 200pf load"

enjoy
Is anyone actually reading the Pioneer statement provided by Timetel?
It is the different resonance behaviour between MM/MI and MC that causes this different behaviour. There are multitudes of graphs on the web to document this.

To consider the C's behaviour with out considering the cartridge construction is strange for me to behold...

I have added C of between 100 - 300pF and the result was a grainy kind of INCREASED treble.
BTW, this size of C does practically NOTHING to an MC, only some 10nF (~ > 100x) will start to show up. IF an SUT is used it's a different matter again, but we are not talking about that right now.

So the cleanest way to increase MM/MI treble is by increasing input impedance (e.g. Raul's 100k), the increased C does ~THE SAME, yet unless some "silvered mica" caps are used, it will sound clearly more grainy.
Seems to me we now do have two schools of hearing...
Axel
Axel, Timeltel, et al, The phenomenon of resonance is one of the factors that I did not specifically mention (along with load R, cartridge R, cartridge inductance, etc) that can alter the outcome when you add or subtract C load. There is nothing mystical about this. Nor does it negate what I wrote (or the two quotes noted above from authorities superior to me) to the effect that load capacitance per se will lower the roll-off frequency at the high end. But when C interacts with R or L, you can have resonance, which could, if the values are by chance conducive, give you a peak right before the response drops off rapidly. Further, Axel, I did acknowledge that since MMs and MCs are markedly different from each other with respect to these other parameters, the effect of load C can be different between one and the other, quantitatively but not qualitatively.

PS. What the heck does it mean to say that "load capacitance should be made equal to cartridge capacitance" (quoting words to that effect noted above)?

To all, I say when you fall in love with your latest cartridge, listen to it for several weeks and then go back to your previous analog love affair. You may be surprised to find that the old girl had virtues you did not previously appreciate. Not even Raul's brain is immune to the tendency to fall for what is novel vs what is well known and understood. In other words, an ABA comparison is much more valid than an AB comparison, even though not perfect.
Greetings, Axel. Regards, Raul: I thought I had sworn off purchacing another MM cartridge but Axel, your account of the Ortofon M20E piques my interest. Your description sounds very much like the type of presentation I enjoy. Perhaps I can justify the purchace of the more spritely Jaguaur "E" stylus only. That, with your assurance that it will accomodate the dignified M20FLeetwood body, which I find a little too relaxed respecting my anachronistic rig, taste, and heavily carpeted and furnished "media room".

As to capacitance, I have no dog in this fight. I only know what I read and experience. This leaves me believing that MM/MI and MC cartridge characteristics are somehow not the same. Perhaps someone could kindly illuminate this with an unarguable statement of effect.
Dear Lewm/Downunder: What I posted is part of what I experienced in this MM/MI alternative times and not with all cartridges and certainly not as a general rule.

The capacitance subject in stand alone way means almost nothing, the meaning of C start to make 2 meaning " when we take in count other related parameters like: cartridge internal resistance, internal inductance, cartridge loading impedance, cable capacitance and phono stage capacitance.
So it is a more complex subject that only C.

The specific relationship between those parameters values are main part of the cartridge frequency response behaivor. If we change the value on one or two of those parameters the result/performance change.
Other factor that we have to take in count is that a change in C does not alter one specific frequency ( stand alone frequency: 15Khz or 4Khz. ) but a frequency range that could alter not only the high frequencies but part of the midrange too and obviously the harmonics response.

Adding to these we have to take in count all the cartridge frequency changes due to the cartridge/tonearm behaivor, cable performance, phono stage performance and line stage performance and IMHO it is after the cartridge signal pass to all these " links " when we can judge about.

I take seriously the whole theory about but unfortunately that theory in many ways is out of target to predict the final " result ".
This is the same like the theory behind the tonearm/cartridge resonance frequency where it can tell us or predict the final " result ".

Downunder, IMHO M. Fremer is wrong with that comment because those 200pf plus the cable capacitance gives you around the 400pf target.

Now, normally a cartridge designer ( especially on its top models. ) makes a cartridge voicing where he take in count all those parameters and when they decided that 450pf is the " number " it is because in their voicing that was " the number ".

Btw, your example/link on the MP-11 is IMHO not a very good example against not only the Nagaoka line ( the MP-11 was at the lower side on MP Nagaoka series. ) but against almost all the cartridges we have on hand and that we are testing and in the other side the system that own that reviewer was not IMHO a good one against many of our systems.

There are a lot of information on the net with different approaches and with different contradictory final " results ", I read somewhere what Mr. Hagherman write about ( something like this. ): " to know the real performance on MM/MI cartridges you have to load those cartridges with 100-150pf, no more. "

Which one of all those theoretical different opinions are right, maybe none because none take in count all the parameters involve in the final result, our ears still are our best judge where the results are system dependent.

I have several experiences ( that I already posted ) where less C are better but this is only my opinion.

IMHO we have to follow in the learning of what " surround " the MM/MI alternative.

Far away of who are right is that we can analize together the subject ( any one of any kind. ) and at he end each one of us take his own decision/attitude about.

Regards and enjoy the music,
Raul.
Dear friends: Please re-read what Timeltel posted about the Pionner Electronics findings ( thank you for that Timeltel. ).

I re-read twice and for that quote IMHO what we want is that peak resonance at high frequencies ( that every cartridge has. ) stay beyond the audible frequency range and we can get it with higher cartridge load impedance and lowering capacitance.

Anyway, as I posted: in my ears I trust!

Regards and enjoy the music,
Raul.
Dear friends: I just bought this cartridge ( Azden top of the line. ) from this ebay seller. I don't receive it yet but I know for sure that its quality performance is great.

Very hard to find in NOS status, as a fact this is the very firsat time I saw/see on sale, IMHO this is a good opportunity to own it. I understand the seller ( I ask him ) has two samples:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=260551502693&ssPageName=ADME:X:AAQ:US:1123

Regards and enjoy the music,
Raul.
Dear Lewm: +++++ " To all, I say when you fall in love with your latest cartridge, listen to it for several weeks and then go back to your previous analog love affair. You may be surprised to find that the old girl had virtues you did not previously appreciate. " +++++

I'm sure is true but in my case and due that I have to test all those cartridges it is almost imposible to me to take " weeks " with each 80+ cartridges.

My " first impression " on the cartridges I test and report certainly could not take it 100% as an " absolute " true but IMHO is a good step to start, I think that some way or the other that " first impression " is around at 85%-90% of the true.

regards and enjoy the music,
Raul.
Lewm,
1) If you want more "air" = less roll-off, best use higher load with MM/MI. (Any added C tends to do more harm then help).

2) Those "recommended" ~higher C (250pF - 450pF) for MM/MI was *never* meant to "roll it off"!
MM/MI roll-off is already more so then with most MCs. It was to ensure a proper match and thereby get most "air" / treble rather then the opposit! (Older phono gear would provided this mostly by default)

3) I'd thought we talked about the effects on "listening" and not electrical theory... Raul had this in mind, so did Timetel and myself.

4) This does not explain why the "E" sounds more dynamic the "FL" --- yet don't even try theory to exlain it... it just does, with my arm, and pre not to forget please :-)
Axel
Guys, my point was simple: the higher the load capacitance, the lower the roll-off frequency. If the roll-off frequency is so high as to be irrelevant to listening requirements, say above 50kHz, then it is a secondary issue or a non-issue. Yes, interaction of C with R or L (inductance) can also give a paradoxical resonance peak. This could account for the observation that adding capacitance may on some occasions make the cartridge sound brighter, rather than duller, if that resonance peak is just in the wrong place. I am sorry to have been a pain in the arse.
Lewm,
Pas du tout! De rien!

Wasn't it a scientific “truth” that: "the exception confirmes the rule"

The other item comes to mind: "It is a sign of higher intellect not to continue with an argument..." O.W.

(How nice to know we so many highly intelligent folks contributing :-)
Greetings,
Axel
Hi,

Has anyone out there tried the Shure Ultra 500? If so, how does it compare to the expriences above with other MM/MI cartridges?
Dear Axel, Who said I aspired to a "higher intellect"? Also, which one of us is guilty of "continuing with the argument"? Habeas corpus. Je ne c'est quois.
A wet bird never flies at night.
Lewm,
yet I guess you just did aspired "higher" anyway, no one seems guilty of prolonging the argument.
"All is for the best in the best of worlds" aye.

Now let's see what master Raul with come up with next for us :-)
A.
Regards, Lewm: I had thought to leave well enough alone concerning capacitance as I do not have the mathmatical chops to clearly define the condition. You wrote "adding capacitance may on some occasions make the cartridge sound brighter, rather than duller, if that resonance peak is just in the wrong place".
To confuse the situation, more from various manufactorers:
ADC XLM MK11: 275pF. @47K Ohm
AKG P8E: 400 "
Empire 2000Z: 300 "
Ortofon VMS20E: 400 "
Shure V15-111: 400-500 "
Stanton 680EE: 275 "
Grace (Shinagawa Musen)calls for 250pF for F9E/L/R, loaded at 100k Ohm.

The 47k resistance load was agreed on in the late 60's (IIRC) when ceramic cartridges were being replaced by MM's and there was no MM standardization to facilitate the transition for those who had "homeowner's" systems, typically inexpensive one piece plastic (like the one I started with) stacked or integrated units. MM's at 47k produced a user familiar sound but was still a compromise. !IIRC!

Back to your post: You wrote "if that resonance peak is just in the wrong place". For MM cartridges, "those resonance peaks" are in the "right place", but only after adjusting capacitance. Unfortunately this does not remain a constant from one example, or even, one cartridge to the next. Pioneer Electronics (1979) also clearly states that by different combinations of load resistance and load capacitance "you will be able to obtain a variety of different HF responses". Can't argue with that. It seems there is no single correct answer, just practical/subjective solutions, except for the exasperatingly dogmatic. I can document this debate back to 1974. Even earlier, Mark Twain said: There are lies, d--ned lies, and statistics. Raul's statement "in my ears I trust" has my vote.

To paraphrase Groucho Marks: If you don't like my capacitance (principles), I have others.
Peace, all.
Regards, Lewm: Hmmm, posts crossing in the ether. I sought to clarify, not dispute, and then Axel out-gentlemaned me while I was keyboarding. If I send a bass bloating Grado MT+ with a worn out stylus, optimistically a 1.0 on Rauls' scale, would you kindly overlook any unintended offence? It's vintage MI, quite scarce, you know. Free shipping in the conti. U.S., my best offer.
Dear Downunder: I just try again the Empire 1080LT and I just can't have a conclusion.

The cartridge makes everything fine, I don't find any serious drawback, it makes " things " very good and could seems that the cartridge belongs to 6-7 range level but there is a cartridge characteristic that I don't like it: it has an uninnvolving performance with no " emotion "/soul, its performance is very good but mechanical ( not analytical. ) more like a good LOMC than a MM/MI.

Maybe my sample needs more playing time ( that I don't have it. ) because is a NOS unit.

Of course that me or any other person can get this kind of cartridge opinion when we make comparisons with other great cartridges, if this was the only cartridge on hand we can say that is a great one but it does not seems to me today.
I try in three different tonearms with little differences but that uninvolving quality performance characteristic stay there.

Regards and enjoy the music,}
Raul.
Raul,
what you find about the 1080LT sounds exactly like my "Malaysia" source feedback. I had mentioned it before (but got the 1080LT twisted into a 1018..)

Question: Would that make for a similar performance compared to the MP-50? It sure sounds like it.

Axel
Raul, Axel

It does need more hours, as I had similar thoughts when I first set it up and played. two other Aussie gents with the 1080LT also found it needed time - Phaser prefers it to his Garrot P77.

Changing the load to the recommended cap of 300pf did wonders in my system adding some fullness and more integrity to the sound.
Timeltel, You cannot go wrong quoting Groucho. My favorite is what he said about Doris Day, who was apparently quite a floozy in private but became America's darling after she made many movies that depicted her as a virtuous innocent. Groucho said, "I knew her before she was a virgin". Both Groucho and Doris probably used ceramic cartridges back in their day.
My new MMCOW - ELAC ESG 795 E/40 cartridge that I bought almost 6 mnths ago NOS for around $150 from memory.

A real pain in the arse to set up in the headshell. changed cap to 300pf per manual. VTF was very low at recommended range of 5mN to 10mN. less than 1gm tracking weight WOW. Does anyone know the exact conversion from mN to gms?

Actually I was expecting not much, however just on several plays I am very pleasantly surprised. Nice deep tuneful full bass with a soundstage that has very good depth. Seems to excel in prat, so far very happy

cheers
Dear Dowunder: I own the Elac 896 cartridge that suppose is a top of the 795 you own.

I bought it more than a year ago with a NOS stylus replacement. Its look is a little " primitive " but the quality performance for what I remember is " surprising " good. I have to test again to be sure about, mine tracks at 1.25grs. but yours has a higher compliance than the 896.

Elac was7is a very " solid " cartridge builder with many many years of experience on the subject so it is not a real surprise that these cartridges performas in high way.

Regards and enjoy the music,
Raul.
Raul, I understand that your 1-10 rating system is purely a subjective way to order the relative performance of the many cartridges you test. And so long as we do not get hung up by thinking "I'd better get rid of X because it is only a 7 so I can buy a Y which Raul ranks an 8," then I think it is useful.

But you confused me with you 2/15 comment, "seems that the cartridge belongs to 6-7 range level but there is a cartridge characteristic that I don't like it: it has an uninnvolving performance with no " emotion "/soul". If there is any characteristic about a cartridge that leaves you feeling disappointed or unconnected with the music, how can you rate it 6-7?

I've been reading your comments long enough to respect your perspective of seeking components which do connect you emotionally with the live music experiences you enjoy so frequently. So how can you rate anything as above average when it does not provide such a connection?

Regards,
Dear Pryso: That was not my intention, I don't explain very well.

As a fact I don't like that kind of cartridge quality performance due to that uninvolving characteristic. I states that maybe that is because it is a NOS unit and needs more playing time ( Downunder confirm this. ).

What I want to tell was that if the cartridge does not show that characteristic then will be on the 6-7 range but right now I can't give it any ranking till the cartridge change through more playing time.

As I posted the cartridge makes everything good with no serious drawbacks ( other than the uninvolving characteristic. ) but in today status I don't want to follow hearing it when I have to many other cartridges to test.

If I can I will let the cartridge playing in one of my TT and see what happen in 10 days.

Regards and enjoy the music,
Raul.
Raul, thanks for the reply. But if I'm not out of line for suggesting it, whenever you test a cartridge that does not come up to your expectation but believe more playing time might help, why write a comment at that time? Why not wait until you are satisfied the cartridge is broken in, then offer your comments?

I offer my suggestion because such short term comments, by Raul or any of us, may not be much help. The only benefit I can see would be to warn others not to expect much until a given model is broken in. But that could be stated simply without yet assigning a rating.

My 2 centavos worth.
Dear Pryso: Downunder posted on that cartridge and its very good performance and other persons like Jaspert ask about and that's why I decide to test the 1080 where I give a normal time of playing like any other MM/MI cartridge I did.

In the other side Axelwhal posted something not very positive on this cartridge from his Malasyan source.

Till that moment I was unaware if the cartridge needs a longer playing time ( unusual/anormal. ).

Before Dowunder posted that it needs more time I posted that maybe it needs more time.

Now I let clear that my intention was not to make a cartridge rating but a way to say that: the cartridge made things good but not fullfill my targets and I still think in this way.

Right now I would like to ask Axelwhal if the similar findings by his Malasyan source was with enough time on the cartridge, say: 30-50 hours.

I understand your claim but due that this cartridge is a vintage one where could be differences in between cartridge samples and that the cartridge needs ( according to Downunder and friends. ) more playing time at least give me /us something additional to take care about for a final rating and as you posted:

+++++ " The only benefit I can see would be to warn others not to expect much until a given model is broken in. " +++++

I could add: not a given model but this one. So not everything were loosed.

Regards and enjoy the music,
Raul.
Dear Raul,
as to the 1080LT play-in time I have no exact information, other than the person had given it "a good try" comparable with his other tests.
It would support (along the line of common sense) that if a cart is lacking in "realness" / "lifeness" it is a tall order to listen to it for 30-50 hr!
In fact most folks would not find it very rewarding to do so --- it maybe your ears in the end being played in rather then the cart?! :-)
In my experience if a cart doesn't show the "right" sort of synergy in one's system, 30-50 hr (so my experience) usually makes little positive difference -- the basic characteristic is never changed as such.
If it sounds quite nice to start with it may get a bit better after a while yet - if something is lacking it hardly much changes that characteristic, AND in fact it may very well be more a system, then a cart issue.
Note: not every one can be good in every one's sack, aye?
Greetings,
Axel
Dear Axelwahl: I agree with you, that were the kind of experiences I had with cartridges.

Even that I want to give the " doubt benefit " to my 1080LT if I find the time to do it. I never spect this cartridge performance for this top rated cartridge so I want to be sure about.

In the mid-time I want to test the Azden YM-P50VL that I just receive it, this cartridge was build by Empire to Azden design characteristics, we will see.

regards and enjoy the music,
Raul.
Dear friends: I take this statement from other thread where Stanwal posted it:

+++++ " Yes, there is general agreement that a more rigid one piece system is inherently superior. This in no way means that replaceable stylus cartridges cannot be good, just that they have to make a compromise that non replaceable ones do not. " +++++

as we know 90%95% of the MM/MI cartridge designs comes with removable stylus and only a few are non removable stylus cartridge designs.

It is ovbious that the cartridge design it-self is the main subject for quality perfromance level but this removable or don't removable stylus design " factor " seems to me important.

The B&O MMC2/1 are non removable type as is the AKG P100LE and I can't be sure but maybe my Grado Amber too.
There are other cartridges that are removable stylus type designs but that comes with a screw to fix in place the stylus ( I mean almost like a non removable ones. ): Technics EPCP100MK4, Audio Technica AT24, Signet TK10ML2, ADC TRX.

All these cartridges are very good performers and I wonder how much " weight " in that quality performance belongs to its non removable stylus design. I know is hard to say for sure because we can't compare against the same cartridge with removable stylus.

I had two experiences about, one very old when I did exactly that: I take the ADC Astrion and glued its stylus body to the cartridge and for what I remember there was an improvement not day and night but an improvement. Three months ago I did the same ( well Van denHul ) with my Nagatron 350 with same result.

Dertonarm posted in this thread that he experienced that subject with an AT-180 OCC with similar results: a quality improvement.

Maybe and just maybe it is time to take this subject seriously and make tests with some cartridges we own.

Anyway IMHO it is an interesting subject. What do you think?

Regards and enjoy the music,
Raul.
Dear Raul,
interesting notion glueing in MM/MI styli...
The ONE! you missed in the fixed list is the MP-50 which is screwed in from both sides, hm. I'd be loath to glue it on top of it!
I do recall hearing the Shure V15 III glued-in giving a ~ better result. (Then what to do with that SAS stylus? :-)
In case one has some "doubles" (like yourself) gluing be not too daring I guess.
Like to hear what Lewm will come up with for this one -- "you can't always get what you want, but then some time and if you try... :-)
A.
Dear Axelwahl: You are right the Nagaoka too.

I think is important to try it. We all know that we can " tame/color " a cartridge performance with different tightness grade/range between the headshell/cartridge mount screws. I like always tight with fierce those headshell/cartridge mount screws, sounds to me less colored.

Well if that is happening between the relationship headshell/cartridge I think that the more intimate cartridge/stylus relationship can have an influence in the cartridge quality performance.

Yes I was thinking on those cartridges ( many ) where I have two-three samples and that several of you own it. The Ortofon M20's could be a good choice.

I would like to know what any one of you that own these Ortofon's recommended as the glue ( please name more than one typebecause I can't find everything exist on USA. ) and how to " implement " in such way that can't damage the stylus plastic body or the cartridge metal/plastic body. The other side is to do it in non permanent way if this is posible.

Regards and enjoy the music,
Raul.
I purchased an M20FL because of this thread and am enjoying it. Thanks guys.

Glueing is an interesting idea. I wouldn't want to do it in a permanent manner myself but I can see possible advantages.

On a similar subject, the M20FL stylus has a stylus guard. I was thinking of removing it, since it is an additional piece of plastic hanging off the stylus that perhaps contributes to resonance issues. Has anyone experimented with removing the plastic stylus guard?

Cheers,
Bill
Dear Williamdc: Normally I always remove any stylus guard, as you point out contributes to resonance issues and that is not good for the cartridge quality performance.

Regards and enjoy the music,
>Raul.
Any recommendations for a glue that could be broken/cut when stylus replacement time rolls around? I would guess Super Glue and similar products to be too permanent. But what about a clear glue intended for plastic models like cars, planes, etc.?

On the other hand, I'll guess those who insert any absorbent material between their cartridge and headshell will not be candidates for stylus assembly gluing experiments. 8^)
Dear friends: +++++ " The B&O MMC2/1 are non removable type as is the AKG P100LE and I can't be sure but maybe my Grado Amber too.
There are other cartridges that are removable stylus type designs but that comes with a screw to fix in place the stylus ( I mean almost like a non removable ones. ): Technics EPCP100MK4, Audio Technica AT24, Signet TK10ML2, ADC TRX. " +++++ plus the Nagaoka MP-50.

it is curious and I don't think it is only a " happy " coincidence but all these cartridges comes with removable stylus guard, it seems to me that these cartridge manufacturers really know what a non removable stylus guard add on cartridge performance colorations along a tight/intimate/non-resonant cartridge/stylus link.

Regards and enjoy the music,
Raul.
Dear Pryso: Thank's for the advise.
I wish more of you can give and advise on this glue subject.

Regrads and enjoy the music,
Raul.
I like the idea of removing the M20FL Super stylus guard, in principle, but I have to admit that if you mount these things on removable headshells, as I have started to do, the guard is really useful, not to say "life-saving". Same goes for the Grado TLZ, that is sitting "cantilever up" but guard-protected in a Dynavector headshell on my cabinet. I don't want to admit how many times the guard has saved the cantilever/stylus from injury and death.
Forgot to say, instead of "glue", I would recommend some Walker Audio silver contact enhancer or a similar product. You could put that stuff right on the frictional surfaces to increase BOTH the solidity of the mating and the electrical contact across them. It's not as full-proof as glue but it is less irreversible. Use the Walker stuff after cleaning both surfaces with Pro Gold or the like. I bet that would result in some dramatic reassessments of some of these cartridges, where we are listening across a mechanical contact that is 30 years old in some cases and has never been cleaned (unless of course others have been cleaning these contact surfaces).