Cartridge loading

Dear @antinn  : Your post is a great learning " food ", thank's.

In the past the Audio, Stereo Review and High Fidelity audio magazines made it such kind of measurements and if I remember other two England ones made it too.

I have on hand the Audio review made it by   B.V Pisha reviewer on the LOMC Ortofon  MC 2000 cartridge. The review is a long one and full of measurements. Here the test records Pisha used for:
Columbia STR-100, STR-112 and 170, Shure TTR 103/|109/110/115/117, Deutsch HiFi No.2, DIN 45 549, Nippon Columbia/Audio technical Record ( PCM ) XL-7004, B&K QR-2010, Ortofon 0002/0003 and JVC TRS-1005.
They took " things " very seriously andn exaustive and way informative. Obviously detailing the analog rig used and after the measurements tests with tortuose recordings as Telarcs and from other labels.

Anyway, thank's again.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

Dear rauliruegas,

The amount of current is just one of the many questions left to answer.  And, I agree with your other statements.  A basic challenge with vinyl is the difficulty in measuring it, and this is very consistent with electro-mechanical systems.  In oil lubricated turbo machinery there is a bearing known as the Kinsbury Tilt thrust bearing that is widely used, and has been for over 50 yrs.  But, Professors have been  studying it for over 50 yrs trying to unlock all of its secrets.  However, my last turbo machinery project was having nothing to do with that; we used magnetic bearings that could generate almost 1 MB of data every minute; we had no trouble measuring everything.

But to me, and I suspect you by your last sentence,  one of endearing qualities of vinyl is the challenge, which pushes it into a different category other than just listening.  It is not plug and play.   Vinyl takes some skill (and tools) and perseverance (devil often in the details) to get it to sound good and that can be very rewarding/satisfying.  However the 'vinyl-challenge' obviously can frustrate some (if not many 😁).  And, there are the unknowns which stimulates the never ending conversation (frustrating some, engaging others, all good as long as we stay civil), and a lot is still an art-form (of course that defies the IOT - Internet of Things🤔).  This site is doing some measurements of cartridges though-
  https://www.lowbeats.de/tonabnehmer-messungen-bei-lowbeats-tests/.  Its in German, but Android devices will translate.  It is surprising that Stereophile has not taken a lead in this area, but JA who for sure leans to digital, is probably less than enthusiastic.  

I am not a luddite as you can see from the 1st paragraph above, but, the true irony may be that this 2015 report "ARSC Guide to Audio Preservation", commissioned by the Library of Congress states:  "Vinyl discs are the most stable physical sound recording format developed to date; they can last 100 years in a controlled environment.", and the Voyager probe carries a gold record that will last for centuries and beyound with simple details on how to play back.  

Best Regards, 
N.

Dear @antinn  : I know that the cantilever could be stiff through that current and all your hyphotesis make sense to me.
The issue is that which kind of  current level is need it to happens that mis-tracking?

Of course that could happens but the reality is that exist no audiophile evidence nowhere of any one that can attest an experience like that.

Now and on the mechanical side the compliance of any cartridge can change over time over the playing hours and normally we don't change the VTF due that the manufacturer VTF range iin LOMC cartridges is to  the coils be centered.

Thank's for your answer. As a fact the issue is really exiting to think/discuss on it.

R.

rauliruegas,

As I said it was a hypothesis, and as a hypothesis, there is no empircal data to support, but for me only deductive reasoning from a multitude of sources that I have addressed in a number of posts. But, your statement that the compliance cannot stiffen beyound some point because of the stiffness of the cantilever without any data does not make sense either.  The compliance is more than than the cantilever stiffness; it includes the suspension, and this is addressed in many of the articles here http://pspatialaudio.com/index_help.htm.   If current in the circuit from the harmonic distortion exists, it can by the back-emf torque the coil to 'effectively' stiffen the the cantilever assembly causing the cartridge compliance to decrease, the stiffer the cantilever, the worse it should be.  As far as an Ikeda non-cantilever cartridge which I have no knowledge of and found no data on the web, but assume is similar to a London-Decca design, the unique design with very low compliance may be immune to this event.  As I implied with the Denon example, for a very low compliance cartridge, the design is so stiff to begin with that there is not much margin/room left to futher stiffen. But, there are medium compliance cartridges with very stiff boron cantilevers. If a medium compliance 22 cartridge with only 1.4-gm VTF was to decrease to 10, but, if at 10 requires 1.8-gm VTF, that is a difference of almost 30%, and in my mind it stands to reason it could mistrack.  It becomes very dependent on the individual cartridge design. I never said, it was for it was for every cartridge. But, the cartridge and tonearm form a mechanical resonance, which is very different from the loading resistor that forms an electrical resonance, but that does not mean that one cannot manifest itself as the other, especially for LOMC.   There is an old saying, We do not what we do not know.   Otherwise, we agree to disagree.  In the meantime, I use only Soundmith moving iron cartridges (Paua & Carmen on two different arms). And, to be honest, after all my reading on LOMC, I highly doubt I will ever dip my toe into those churning waters. 😁

Dear @antinn  : There is " something " in your 4. point where you said:


"""  The stiffening of the cantilever assembly will cause the cartridge effective compliance to decrease. If the LOMC cartridge is a medium compliance with low VTF, then it stands to reason that the cartridge will likely miss-track at audible frequencies. """

Medium compliance, this is what P.ledermann states about: 

"" medium to low compliance cartridges. Cartridges with a compliance between 22 and 10. Most cartridges are between 22 and 10 in compliance.  ""

I asked atmasphere that proposed the same ( almost. ) hyphotesis you posted in  point3. and 4. that he showed wich kind of electrical current must need it not to stiff the cantilever but to make the stylus tip mistrack groove modulations.
A medium compliance LOMC device say 16cu normally be a very good tracker even in very high velocities recorded in the LP grooves an even if are recorded at the most inner recording LP surface.

Now, I posted that for that medium compliance cartridge could has a mistracking problem that compliance has to goes really low, lower than 10cu and this is almost impossible that could happens with the stiffness of the cantilever.
Not science only common sense. I would like that you or other gentleman come here to shows those " numbers " that can cause the effect detailed in your 4. point. At the end it's the discussion main issue.

Ikeda designed non-cantilevered cartridges with extremely low compliance and obviouly with 1gr higher VTF that a medium compliance that normally comes with 1.5gr and up and I never read any report of such kind of problem you posted and that was what I asked to atmasphere.

Your hyphotesis probably can't be proved it can happens .

In the other side, no single audiophile in no single audio forum sites over the world never reported that phenomenon.

Seems to me that's more easy that the mistracking happens with a bad mistmatch between cartridge and the tonearm about resonance frequency in between that by the loading resistor combination with the cartridge/phonostage. Only an amateur opinion.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

bydlo,

After further thought, here is my best hypothesis, and it really is just a 'perfect storm', for all the variables to come together.

1.  Many LOMC cartridges have very wide bandwidth, out to 47kHz and maybe even beyond.  So, the harmonic distortion that starts the event may begin at a very high inaudible frequency.  

2.  For capacitors used in audio such as Elna, Nichion, etc, a 25V, 4.7uF capacitor may only be rated 25mA, but this rating is at 120Hz.  There is a Coefficient of Frequency for Rated Ripple Current that for higher frequencies, you can add 20% or more to the rating.   But, the capacitance can drop with higher frequency, so this all adds uncertainty.  And. as I addressed in my very first post, per this very old article www.aes.org/tmpFiles/elib/20200131/2623.pdf; the preamp design has a lot of influence on the entire circuit.

3.  If the event first starts at very high inaudible frequencies, and the preamp circuit saturates, overloads, oscillates or otherwise becomes unstable, and if a current surge occurs, then the LOMC cartridge may now try to function as a moving coil instrument https://www.yourelectricalguide.com/2017/01/permanent-magnet-moving-coil.html; "When the moving coil instrument is connected in the circuit, the operating current flows through the coil which is mounted on the spindle. Since the coil is placed in the strong field of permanent magnets, a force is exerted on the current carrying conductors of the coil which produces deflecting torque.".  

4.  If item 3 above occurs, the cantilever will stiffen.  The stiffening of the cantilever assembly will cause the cartridge effective compliance to decrease.  If the LOMC cartridge is a medium compliance with low VTF, then it stands to reason that the cartridge will likely miss-track at audible frequencies.  If the LOMC cartridge is a very low compliance (i.e. Denon DT103R) with high VTF, it may not miss-track.  However, when the cartridge cantilever assembly stiffens and the effective compliance decreases, the cartridge-arm resonant frequency will increase, and this 'may' depending on the cartridge-arm combination increase the cartridge-arm mechanical resonant frequency into the audible range.

bydlo,

First, the sequence of events is dependent on the cartridge and the pre-amp.  One of the premises of this entire thread has been the limits of 'some' pre-amps.

This article is an extension of the first Shure article I referenced, and it goes deeper into the cantilever stiffness, with the risk of mistracking at high velocity.   http://pspatialaudio.com/analogy.htm#cantilever.  This mechanically induced instability will lead to harmonic distortion.

From this article https://www.analogplanet.com/content/current-affair-intriguing-mr-labs-vera-20-mc-phono-preamplifier, the statement is made that LOMC  "Moving coil cartridges output very low voltages but relatively high current on the order of tens of micro-amperes".  Dynamic microphones that operate on the same principle, state current output. https://www.audio-technica.com/cms/site/b0d226992d31e25d/index.html/

Depending on the pre-amp, using this as an example, https://sound-au.com/project06.htm, if there is a line to line capacitor with no dampening resistor, and IF the capacitor saturates from the harmonic distortion, then the events should be setup for a high current to occur.  So, it may be that the mechanical instability begins the event, but the consequence is that a small mistracking event can cause harmonic distortion that because of the poor preamp design leads to an even larger mistracking event.

@antinn

That article was modeling the mechanical resonances as an equivalent electrical circuit. I was trying to show that the mechanical resonances were more complex than I originally thought, and if the cartridge goes into physical resonance (which is more likely at high frequency), then there will be a high harmonic distortion (EMI/RFI) produced.

Indeed it's more complicated than just a mass on a spring as there comes into play the vinyl resonance (I admit I never thought about that).
But getting a mechanical resonance radiate into RF range I think is not easy. Ultrasonic yes, but RF we are talking about some 40-50kHz at least.

Its my understanding that LOMC, are poor voltage generators, but good current generators which is why the new generation of LOMC preamps are current sensing.

Again: MC and MM cartridges work by the electromagnetic induction. What they generate is voltage. What I mean is if you play a cartridge unconnected what you will measure on its pins is a voltage but no current flow as the circuit is open. So cart is a voltage generator. Now, you in the electric circuit theory you can exchange current and voltage sources on the paper. You can redraw any circuit using voltage sources to current sources and vice versa. BTW the current source at teh Shures schemtics is wrongly drawn. Series resistance makes no sense with current sources. What I suspect the "current generator" thing mean is that LOMC's have a low internal resistance so for a given output voltage they will push more current. And this is of course a fact.

If a capacitor saturates because of the high harmonic current, and there is no dampening resistor, the only thing that is left is the capacitor equivalent series resistance (ESR). If the circuit current suddenly increases, this will by the back emf, dampen the motion of the cartridge armature (stylus-cantilever-suspension), and may depending on where on the record this is occuring (i.e. radial velocity), cause miss tracking. So long as the current was not outrageous and the capacitor is not damaged, and most will self-heal, once the current drops, the capacitor returns to function. So the event can be very transie

Sorry, cannot understand what you mean here. Which capacitor? Can you point me to the relevant passage from your links?

The topic about Cartdige Loading is hot.
But here is something about Speakers Loading from Zu Audio:

https://www.zuaudio.com/low-voltage/2020/1/24/loading-resistors?mc_cid=709c630e33&mc_eid=cdb0d19c49

Around 1980, the B&W and Audire Florida rep was my neighbor near my family's St Augustine beach house.  He turned me on to both brands, and suggested a Supex 900 E+ M/C to replace my Ortophon.  I bought an Audire Diffet 1A  preamp, which had a three position impedance selector.  He changed the 40 ohm input resistor to a 10, really opening up that cartridge.  BTW, I had thought my Phase Linear Stacked Advent system was good, which is was for my grad student party system, but he enlightened me. 

Bydlo,

That article was modeling the mechanical resonances as an equivalent electrical circuit.  I was trying to show that the mechanical resonances were more complex than I originally thought, and if the cartridge goes into physical resonance (which is more likely at high frequency), then there will be a high harmonic distortion (EMI/RFI) produced.  Its my understanding that LOMC, are poor voltage generators, but good current generators which is why the new generation of LOMC preamps are current sensing.  If a capacitor saturates because of the high harmonic current, and there is no dampening resistor, the only thing that is left is the capacitor equivalent series resistance (ESR). If the circuit current suddenly increases, this will by the back emf, dampen the motion of the cartridge armature (stylus-cantilever-suspension), and may depending on where on the record this is occuring (i.e. radial velocity), cause miss tracking.  So long as the current was not outrageous and the capacitor is not damaged, and most will self-heal, once the current drops, the capacitor returns to function.  So the event can be very transient.  

When you say, RFI, are you talking radio frequency interference, or in general, electro-magnetic interference (EMI)?

@antinn Thanks for your comments!

RFI, not EMI. The RFI is caused by the tank circuit created by the cartridge inductance and tone arm cable capacitance. It is driven into excitation by the cartridge energy.

Don’t really buy the RFI argumentation, sorry. Putting aside simple and super cheap solutions like grid stoppers existing for decades, I cannot see how the RFI conspires to always give the effects exactly mimicking underloaded (high R) cartridge.

@bydlo

Grid stoppers amazingly are not used in all phono preamps! Some designers have ’not heard the gospel’ so to speak ;( But more to your point, I’ve yet to see an audio circuit that sounds right if it is having problems with RFI. The ’cartridge loading resistor’ detunes the tank circuit at the input of the preamp. With most preamps if they are RFI sensitive, this will cause them to be less bright as there will be less intermodulation. Intermodulation contributes to brightness as the ear converts all forms of distortion into tonality.

the cart model of Shure brothers analyzed there is *unloaded* (plus the current source is strangely drawn with series (??) instead of parallel source impedance). The R on the schematics is the mechanical damping of the suspension, not the loading R.

Shure to my knowledge never made a LOMC cartridge. My comments about RFI relate only to low output cartridges. MM cartridges are an entirely different matter, as the resonant peak is often at or near the top of the audio band. They are also capable of ringing at audio frequencies as their inductance is so much higher, so to use a MM effectively, proper loading **is** required.

@antinn Fantastic source, thanks Antinn for sharing! But the cart model of Shure brothers analyzed there is *unloaded* (plus the current source is strangely drawn with series (??) instead of parallel source impedance). The R on the schematics is the mechanical damping of the suspension, not the loading R.

All,
Re-reading my response above, I failed to address the actual question.  So, did some more research and came upon the site,  http://pspatialaudio.com/index_help.htm which has a wealth of historical data, with detailed info, lots of calculations, and this article  http://pspatialaudio.com/analogy.htm presents an interesting model of the equivalent circuit of the dynamic system of a phono cartridge.  While it does not clearly show that harmonic distortion can mimic unloading, the mechanical resonances are not so simple".  Depending on the design of electrical circuit, harmonic distortion can saturate capacitors and inductors thus shifting the electrical resonance frequencies, and if they coincide with the mechanical resonances, there should be no reason that the circuit in the presence of the high harmonic current behaves as if the cartridge is unloaded. 

@intactaudio

Now, as the force against the groove wall lessens
momentarily,...

Very much agree with that. EMF damping I’ve been talking about. Thanks for sharing Dave.
@atmasphere Don’t really buy the RFI argumentation, sorry. Putting aside simple and super cheap solutions like grid stoppers existing for decades, I cannot see how the RFI conspires to always give the effects exactly mimicking underloaded (high R) cartridge.

atmasphere,

The article I referenced was only to address the affect of inductors.  When you say, RFI, are you talking radio frequency interference, or in general, electro-magnetic interference (EMI)?  EMI encompasses conducted emissions (CE) , conducted susceptibility (CS), radiative emissions (RE), and radiative susceptibility (RS). My background includes testing equipment to EMI requirements, so I am just trying make sure we are on the same page when communicating.  However, Peter at Soundsmith addresses the concept of stylus jitter https://www.sound-smith.com/articles/fixed-coil-vs-moving-coil-why-make-jump-different-technology. 

I also have experience with vibration testing.  So when I read all this, my analogy is that stylus is tracking the record such that you want the transmissibility (essentially the ratio of the record grove to the stylus-cantilever movement) to be unity, that way the stylus-cantilever reads exactly the groove.  If the transmissibility drops below unity, then the stylus-cantilever-suspension is absorbing energy and there will be loss of data.  It may read the frequency correctly, but the signal output will be lower than normal, and this could be frequency dependent, so an oscilliscope trace may show some 'suck-out' at the affected frequencies.  The list of items that can cause transmissibility less than unity can be of mechanical origin (such as too much VTF) or electrical (such as circuit speed).

If the stylus-cantilever-suspension transmissibility is greater than unity, but not resonating then it will output more data than what is on the record, i.e. it may read the frequency, but the signal output may be high than normal, but again this may be frequency dependent.  So, an oscilliscope trace may show some peaking at the affected frequencies.  The list of items that can cause transmissibility greater than unity can be of mechanical origin (such as VTA) or electrical (such as cartridge loading and maybe an electrical circuit causing a weird impedance).

However, if the stylus-cantilever-suspension resonates, the transmissibility increases many times causing the stylus-cantilever assembly to move far greater than what is in the groove, thee output signal to increase proportionally, and depending on whether the stylus maintains groove contact, and depending on the pre-amp overload margin can lead to massive harmonic distortion (smearing of the output signal, i.e. conducted emissions) with distorted sound, and/or pops.  

Ergo, anything that effects the stylus-cantilever-suspension stiffness, be it of mechanical or electrical origins can affect its ability to properly read the groove.  And, since low, mid and high frequency information can simultaneously exist, there can be shall we say over 20,000 opportunities for this unravel.   Yes, its a mircale that this works, but as Corey Greenberg said many years ago, a 1000 years from now, good luck trying to find a CD player, but you could play a vinyl record with a pine needle.

Dear @intactaudio  : Yes that could be because limit the tracking stylus tip is not so easy and if we are " thinking " to do  by the loading electrically  effects the posibility to overdamps the stylus tip motion in unimaginable due that the stylus tip motion inertia is really high.

The more " extreme " mechanical stylus tip damping exist through the Townshend TT where the oil/silicon damping is practically at the stylus tip and things are that just no overdamping, I had the experience to listen at least twice that TT/tonearm andthe kind of damping it has makes a very enjoyable listening experiences. More as the last sentences PM information you shared.

R.

@intactaudio That is what the 47K input standard is supposed to be for- a slight amount of damping. I don't see in the text you quoted how the cartridge was set up- was it driving a very high impedance as a control or 47K?
@antinn  The interesting article you linked refers to self-resonance of inductors as a consequence of using them in equalization circuits. I don't see anything in that article about how the RFI generated by a cartridge can interact with the phono section. Pete Millet's website is quite an asset to those interested in audio!


What I have found is that there are two aspects of RFI issues in phono preamps. The first is pretty obvious; the resonance of the tank circuit caused by the cartridge inductance and the tone arm cable capacitance. This can cause overload of the input circuit if it has poor overload margins. The other is less obvious which is the inherent stability of the circuit. There is a device known as a 'stopping resistor' which is used to prevent oscillation at the input of a grid (in the case of tubes) or gate (in the case of FETs). But some designs don't use stopping resistors and can oscillate briefly if presented with the right circumstances. This is how a phono section can generate ticks and pops; this is a fairly common problem is why many people think than LPs are a lot noisier format than they really are. 

 Now, if someone can find International Audio Review 5, 1980 pp.31-159, the answer to the existental challenge of prove-it may be answered.

Have a copy in hand....   which is why I took exception to the thought that loading a cartridge down must adversely effect the ability to trace high frequencies.    I think the following text from IAR 5 sums it up pretty well

Now, as the force against the groove wall lessens
momentarily, the stylus’ motion is no longer as damped
by the compliance (springiness) of the vinyl interacting
with the mechanical impedance of the stylus assembly.
The stylus assembly is, as John Curl has put it, more
on its own. And that’s when the additional damping
imposed on the stylus motion by the electromagneto-
motive effects of Lenz’ law and a low load resistor can
come into play. Stylus tip damping, from whatever
source, helps the stylus assembly to cope with groove
rattling problems (note that cantilever pivot damping
in the cartridge might not, especially at higher fre-
quencies).

maybe accurately tracing high frequencies is the wrong term and loading can help prevent the creation of "non-source contained" high frequency information.

dave

rauliruegas"The issue is that no evidence/measurements/numbers of that non-existent " limit trace "

That has been clearly and definitively explained in thorough and complete detail so what is it that you are arguing about it is a mystery to some of us hear!

Atmasphere,

No arguments of the electrical-mechanical fundamentals, but the aspect is not well doucumented for cartridges, and therefore, the nay-sayer(s) will debate.  However, that being said, this document shows how the phono-preamp design can affect the performance. And, lets not even begin to discuss how Impedance is often incorrectly used for resistance, with Impedance = Resistance + Reactance and is frequency dependent, whereas resistance is fixed.
 http://www.pmillett.com/file_downloads/LR%20Phono%20Preamps.pdf

atmasphere I'm not questioning if you have a conversation with JC.

Good. Because you misread an earlier comment of mine and came up with this nonsense:

Atmasphere mentioned WBF where JC participated and in that forum JC never mentioned that " limit trace... " that ( for me ) exist only in the atmasphere imagination

What I had said was not that Jonathon had written about it, I said that he and I had a conversation about this issue at Munich. Very specifically it was he that brought up the compliance of the cantilever being affected by the load the cartridge has to drive IOW becomes stiffer as the load resistance is reduced. Anyone familiar with electronics would instantly see how this is the case.

Now, if someone can find International Audio Review 5, 1980 pp.31-159, the answer to the existental challenge of prove-it may be answered.

A simple understanding of how electro-mechanical transducers like loudspeakers and cartridges work is all that is needed. It should be no surprise that Moncrieff experienced something like this; what is surprising is that it was not reported earlier, but its been my position for the last 20 years or so that the implications of using a transducer based on an inductive principle haven't been fully realized by the hifi industry.


It was pretty obvious to me all that time ago that most phono section preamp designers were not taking into account how the resonance created by the cartridge inductance and the capacitance of the tone arm cable interacts with the phono preamp. Its not just a matter of enough gain and proper EQ; its also a matter of RFI immunity and internal stability of the circuit. If the latter two are properly addressed the need for cartridge loading for a LOMC cartridge is moot.

All,

This artcle http://www.gammaelectronics.xyz/s_1987-8_cartridge-tweak.html, makes the following statement "The importance of the resistive load across the output of cartridges was reported by J. Peter Moncrieff in 1980.[2] He found that a lower shunt (parallel) resistance reduced distortion levels: he postulated that the reduction in distortion was due to electromechanical damping being applied to motion of the stylus assembly (though others were unable to replicate his findings to anything like the same degree)" which would support the premise that electrical loading can affect the mechanical function of the stylus.  Now, if someone can find International Audio Review 5, 1980 pp.31-159, the answer to the existental challenge of prove-it may be answered.

atmasphere I'm not questioning if you have a conversation with JC.

The issue is that  no evidence/measurements/numbers of that non-existent " limit trace " that till does not appears evidence for me is only your imagination/hypothesis.

You said that JC posted about on wbf and that's why I posted all what JC posted down there and exist no reference to that limit trace. 
I know JC and know that he post only information where he already corroborated with facts.

That's all.

R.

Started out interesting...got a little personal...then brain damage set in. I think I’ll load the cartridge where it sounds the best to me, take a Tylenol and let y’all hash it out. Cheers!  
btw thanks @atmasphere for your normal well thought-out and non-combative posts

Can I just ask if others have found that say 100ohms on one cartridge for a phono stage is altogether different on another phono stage?

@noromance 
great explanation of cartridge loading BTW - I wish someone explained that to me many moons ago - before I read around and figured it out

Dear @lewm  :  """  I would posit that subjective testing based only on listening is fraught with error, not the least of which is error due to listener bias..""""

do you already made the tests I did it? no? then just do it and you will know that that " listener bias " just does not exist because what you are looking for is if you can detect " anomalies " ( other than little changes due to differences on SPLs due to the load resistor. ) in the specific HF range.


Those kind of listening tests is a good approach to confirm that at least by our ears/brain there is no limit trace problem with the cartridge tracking abilities.

Taske your time and try it or not, is up to you.

R.

Dear @lewm  and friends : This was the main subject in the first intactaudio post:


"" article in IAR #5 by Peter Moncrief titled "Audio Fallacies Exposed Low Impedance Loads for MC Cartridges" about loading and he proposes that loading down a cartridge helps it keep better contact with the grove. ""

Years ago too Palmer posted in Agon as an answer to atmasphere:

"""   not on tracking which is demonstrably false based on IM tests on tracking performance that I have incidentally performed as a function of load. """

@atmasphere  thank's for your comments and I and maybe some one else would like to know which is that "  in my sample set ".

R.

Dear friends: Yesterday I mounted the Talisman LOMC cartridge that's an extraordinary performer and I did exaustive tests " plñaying " with load impedance and capacitance and no matters what and even that my system has very high resolution with every kind of distortions at minimum I can't detect/be aware of no single anomaly in the HF range and I put focus on that HF range. Nothing.

So with LOMC cartridges  current or voltage phono stages designs makes no diference in that  loading subject where that " limit trace " does not exist.

So and due that over 95% of the phono stages are voltage designs the important issue down there is the overall quality levels of the design and the quality levels of the excecution of that finished design on the market.

Btw, no one of the LOMC cartridges that I tested performs in a superior way when loaded at 47k, always inferior quality levels against lower loading values. My MM/MI I " historically " load it at 100K.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

Raul, Likewise, I wrote the above post before I saw your response to Dave.  No problemo.

For the record, I did mention the relationship between the input impedance of the Intactaudio device and the output Z of my MC2000 (2 ohms into 20 ohms), by way of speculating on how it is working with that particular cartridge. Nearly any very LOMC cartridge with a very low internal R would tend to work with the IA device in a voltage-dependent manner, I guess.  Still, the IA device also sounds great with one of my other LOMCs that has a high-ish internal R and where the amplification would be more in the current domain.  (Dynavector 17D3 which has internal R = 32 ohms.) Be that as it may, I am driven to try out a very very low input impedance phono some time, with the MC2000, just to satisfy further my curiosity.

Raul, When IA used the term "tests", he meant exactly that.  He made measurements using the proper test gear and said nothing about listening tests.  Not that there is anything "wrong" with either approach, except I would posit that subjective testing based only on listening is fraught with error, not the least of which is error due to listener bias.  Furthermore, Dave (IA) was not per se testing Atmasphere's hypothesis that low resistive loads impair HF tracking.  He was testing a finding put forth by Moncrieff, to the effect that unloaded LOMCs (i.e., with a 47K ohm load) exhibit a form of IM distortion (when he used one particular pair of frequencies for his IM test) and that the distortion is reduced when you use progressively lower resistive loads, down to 100 ohms. Nevertheless, Moncrieff's and Dave's measured findings might (or might not) provide a scientific rationale for your position.  As for me, I wonder about the particular pair of frequencies that Moncrieff used for the IM test and whether one might get a different result for other pairs of frequencies.  (I think the upper one was 4KHz; would that be high enough for the effect described by Atmasphere to kick in?) Or for different cartridges.  (I don't know what cartridge was used by either Moncrieff or Dave.)  Finally, I personally wouldn't care if using a 47K load produces a bit more measurable distortion, as long as the result sounded closer to live, real music compared to a 100R load.

Dear @intactaudio  : Thank's for the clarification I understand it in diferent way.

At the end through measurements or listening tests seems to me that only you, PM, JC, Palmer and I " experienced " that loading subject and its effects, at least according with the facts I have on hand.

Sorry @lewm  you was rigth.

R.

Raoul,

Yes...  I confirmed the results via measurement.  I did not put forth any listening impressions.

To be clear the stage that Lew M is using is not a current amp in the true definition of the term.  Its circa 20Ω input Z is multiples enough of his cartridge internal impedance that it acts as a traditional voltage amplification stage.

Dear @lewm  :  Not subjective you are wrong. Here is the very first intact audio post in the thread when he shared the IAR PM findings on the loading subject:

"""  Being the Skeptic that I am I repeated his tests and confirmed his results..  """


R.

Raul, Intactaudio made measurements of frequency response and IM distortion, I think. You are here reporting your subjective impression, which is fine, but there’s a big difference. 

I bought a BMC MCCI current injection phono stage 2 months ago and agree with your assessment . I just had a Lyra Claves De Capo repaired By Steve @  VAS  . Best vinyl playback in my system to date . 2 ohm & 0.25 mv  stunning 

About 3 days ago i hooked up my current-injection phonostage (47 Labs Phonocube) to my system and i was blown away! We were sitting here with a friend of mine who often comes to my apartment. Even him is quite familiar with the sound coming from my two Luxman PD-444 turntables with various tonearms and cartridges, using different phono stages. Prior to that we already selected our "cartridge of the month" just for fun, it was an MI cartridge (Grado Signature XTZ) connected to WLM Reference phono stage with upgraded load resistors (100k Ohm Vishay). The second best was LOMC Fidelity-Research FR-7fz connected via Luxman toroidal silver SUT to JLTi 47k Phono stage, probably it was too bright.

I want to tell you that same FR-7fz on FR-64fx with W-250 counterweight and N-60 stabilizer never ever sounded as good as with the 47 Labs Phonocube phonostage. The impedance of this cartridge is 5 Ohm, the output is 0.24mV. Prior to that i have tried this cartridge with Gold Note PH-10 phonostage direct, with WLM and JLTi direct, also with ZYXCPP-1 headamp and with two different SUTs too.

With 47 Labs Phonocube the cartridge became so alive and emotional contact with the music is so strong that i can clearly say this is the best phono stage i have ever heard. We did the same next night and again and again... My feeling is like i’m right there with musicians, the sound is so dynamic and open that it’s a kind of psychedelic experience. The rest of the chain is passive Pass Aleph L preamp and First Watt F2J current source power amp, upgraded Zu Audio Druid mk4 speakers with latest Zu Audio drivers (101db) and Radian super tweeters.

What i am gonna say here:
With current-injection phono stages you don’t have to think about loading at all, no optional loading! But it’s completely different experience with relatively low impedance LOMC cartridges. And i did not try my Phonocube with Miyabi cartridge yet, so i can only imagine the result, because it was designed for Miyabi. I decided to check FR-7fz with Phonocube because i am using this cartridge in my system often and i thought i knew its character.

I believe our @lewm experienced something similar with his new current injection device with his MC2000.

My advice to others:
FORGET ABOUT CARTRIDGE LOADING!
Look for current injection phono stages for your low impedance LOMC cartridge, there are quite a few on the market. None of the conventional phono stages with optional loading in my arsenal (like the Gold Note PH-10 with PS-10 or JLTi mk4 for exampe, or my WLM Phonata Reference) are even close to the sound coming from the current injection little phonocube (without optional loading).

I am using original Phonocube, but here is a DIY version with schematic (to read how it works). 

Dear friends: Yesterday I took my time to make some tests on the controversial and now confirmed false issue:

I used the Carnegie 2 LOMC cartridge using same LP tracks in all tests some choosed for its high recorded velocities in HF and choosed tracks between the middle of the surface LP to the inner surface positions:

I runned first at 47K using additional 550pf along the cable capacitance. I runned to with out that added capacitance.
The performance was exactly the same with no additional any kind of noises/disturbances: not found out higher SPL in the clicks/pops.
The listened quality performanse is inferior that when loading is at 100 ohms.

Next I runned at my normal 100 ohms loading and no added capacitance and performed as I’m accustomed to listen it.

After that I lower the loading to 50 ohms and other that a lower lower SPL the HF response was not altered by .

I tested the 103D too with similar results. I had an accidente and I bended the cantilever and this gives me the oportunity to up grade this cartridge and test its improvements on quality performance level.

So both issues: higher click/pops and " limit trace...HF " does not exist. The theory is rigth there but tjhose issue just does not exist.

Almost any one of you can confirm by your self about making your own tests. Till today I know that intactaudio made it on the LOMC loading and now I.

Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

I forgot to say that I made the same tests with two diferent phono stages.

A secondary issue is whether or not the cartridge was built with some form of electrical damping in mind with the intent of thus creating mechanical damping. This seems problematic as the compliance of the cartridge is directly affected- that being the case a range of loading values would be specified for a given effective mass and we certainly are not seeing that in the spec sheets!

@atmasphere  I'd imagine the compliance change may not be big in the manufacturer specified load range so no one cares. Plus  load optimization is usually done by ear anyway.

Dear @intactaudio  : atmasphere posted to you:

"""   first, 47K is the industry input impedance standard for phono preamps. Second, I had a conversation with Jonathan Carr (well known of Lyra fame) on this very topic and it was he who mentioned to me that loading at 100 ohms or the like would have the effect of reducing high frequency performance....""

btqw, the 47k industry standard has no direct relationship with LOMC because 47k was choosed for the MM cartridges before the existence of MC cartridges and even that latter on appeared the MC 47k stays for the owners can use SUTs because does not existed active high gain phono stages.


Now, atmasphere said: " i had a conversation... "" . He talked with no evidence of that conversation that showed that " limit trace  " in anyway.
Atmasphere mentioned WBF where JC participated and in that forum JC never mentioned that " limit trace... "  that ( for me ) exist only in the atmasphere imagination and as Palmer said is false..

Here are the main JC highligths when he posted down there in the loading subject:



"""     Regarding loading of low-impedance MC cartridges, in general I recommend trying to reduce any capacitances present between cartridge and phono stage input to as little as possible. Use the lowest-capacitance phono cable that seems decent, turn off any additional capacitance in the input stage of the phono amplifier etc.

The reduced capacitance should make it possible for you use a wider range of loading impedances without having the sound go bright, peaky or thin-bodied. Conversely, any excess capacitance between cartridge and phono stage input will almost certainly force you into choosing lower loading impedances to save your ears.

Being able to use higher-value loading impedances should allow you to hear more of the dynamics and resolution that the cartridge is capable of, while using lower-value loading impedances will limit how much of the cartridge's dynamics and resolution that you can usefully extract.

As you said, live music is energy, and audio reproduction equipment should suppress that energy to the least extent possible.

hth, jonathan  """


normally cables does not comes with low capacitance ( 32pf as the JC cables. ) but a little high one.




"""  My comments are based on an objective understanding (measurements, calculations, and simulations) of what a low-impedance cartridge generator is, what an interconnect is, what happens when the two are combined, what happens when resistors of various values are added to the mix, and what happens when extra capacitance is added. A low-impedance cartridge has an inductive generator, while a phono cable has significant capacitance. Put the two together and you get a huge spike at ultrasonic frequencies. These frequencies are much too high for any human to hear directly, but fall in a band that is likely to impair the linearity of the phono stage in much the same manner as excessive RF. When we "load down the cartridge", for the most part we don't affect what the cartridge does at all (unless the value of the load approaches or drops below the internal impedance of the cartridge). What adding resistive loading at the phono stage input accomplishes is to dampen the resonant energy of the ultrasonic spike, and give the phono stage an operating environment isn't so likely to trigger any latent non-linearity tendencies that the phono stage circuitry may have.

For the reasons given, the phrase "cartridge load" is misleading. "Phono stage input terminator" is a better description of what really happens.

Increased capacitance between cartridge and phono amplification circuitry will lower the frequency of the ultrasonic spike, which requires the application of lower resistive values to dampen the spike. Reduced capacitance between cartridge and phono amplification circuitry will increase the frequency of the ultrasonic spike, which can be tamed with higher-value resistive values.   """




some one there tell JC the first statement here and followed by JC answer:


""" 
you are not really affecting the audible high frequencies with any resistive load shown.

JC: 
Not directly, no. To claim that the loading affects the measurable frequency response of the cartridge is bogus. However, if inappropriate loading bathes the phono stage in copius amounts of high-frequency noise, it may start to distort (unless the designer implemented various techniques to make sure that this won't happen), and the result will likely be intermodulation distortion. IMD products can go low enough to fall within the audible band (even when the stimuli are ultrasonic), and IMD nearly always is not harmonically related to the signal, making it particularly grating to the ear.   ""


JC followed wiith this on his cartridges:



""" When authoring the documentation for our post-2009 cartridges, I went up as high as 600pF cable capacitance (to cover audiophiles who may keep their turntable in a separate room / closet). The official loading recommendations for the Delos, Kleos, Atlas, and Etna reflect this wide range of cable capacitances, and the inclusion of highly capacitive cables for special circumstances is why you may see loading values as low as 95 ohms suggested in our literature. """


"""  jc
Higher capacitance values should be paired with lower resistance values, and vice versa.

The loading resistor value is placed across the phono cartridge's output terminals, which means that any output voltage produced by the cartridge will be forced to flow through the load resistor in the form of current. The higher the load resistor value is, and the farther the net impedance is from the cartridge's internal resistance, the less current will be produced. Conversely, the lower the load resistor value is, and the closer the net impedance is to the cartridge's internal resistance, the more current will be produced.  """


This is what a pair of audiophiles posted there:


"""  I have been experimenting lately with resistive loading on my Pass XP-27 phono stage. I am using the stock SME phono cable that came with my 30/12A table. I have an AirTight Supreme cartridge. I am finding that my previous setting of 47K ohms now sounds a bit flat and thin to me. There seems to be a lot of resolution and dynamics but the sound is a bit less natural or real than I am finding with lower settings. I have been gradually lowering the load values (increasing the load) and am now comparing the 500, 350, and 220 ohm settings. I prefer these because they seem to improve the sense of weight, body, tonal richness and warmth of real instruments without seeming to diminish dynamics, liveliness or resolution. In fact, the resolution seems greater. There is also an increased sense of palpable presence and more natural sound.
 Nick (Doshi) also pointed out that the added "detail" at the say higher loadings actually obscures "real" information. I hear what he’s talking about with the Atlas and other cartridges


My MSL Platinum signature was best with 250ohm at the time with Magico M3 and pass xp-25. Now with Pass xs i prefer 330ohm.
1k and higher it becomes thin and i hear distortions.

So i think your recent findings are right. """



 @intactaudio  and friends we can read in those posts that JC never mentioned " limit trace... ".

JC is very knowledge gentleman not only in cartridges that's his speciality but he knows a lot on tonearms, TTs and Phono Stages because he contributed in a very well regarded PS design and build it.
I know him very weel and I know that what he post he posted because he has evidence because he always makes calculations, charts, modeling and the like. He is not a stupid person, is some one I respect a lot even that in the past he and me do not been in agreement in some issues mainly because my amateur knowledge levels.


Btw, here what Ortofon said on the loading issue and that's different to what JC posted:

"""  The lower the load impedance, the higher the current and the more dynamic the sound.

Best regards
XXXXXX
Ortofon A/S

[FONT=&amp]Playing with the input impedance means also playing with the sound character. The influence of the load impedance on the differences in sound is caused by the change of the crosstalk levels and the amplitude raise at the resonance frequency. The lower the load impedance, the higher the current and the more dynamic the sound.[/FONT]  """



So and for me, the " limit trace..."  issue is still false till some one can comes here ( as @lewm said: jumps here. ) and proves/shows true evidence and not bla, bla.


Regards and enjoy the MUSIC NOT DISTORTIONS,
R.

 As for 47K being the optimal load, I see all kinds of manufacturers suggesting values other than 47K as the optimal load for their cartridges.  

47K is the industry standard; as far as what it the optimal load that is what this thread is about :)

47K only work under a limited range of circumstances - mostly whether or not the phono section is stable enough to deal with the ensuing RFI to which it will be presented when dealing with that impedance. A secondary issue is whether or not the cartridge was built with some form of electrical damping in mind with the intent of thus creating mechanical damping. This seems problematic as the compliance of the cartridge is directly affected- that being the case a range of loading values would be specified for a given effective mass and we certainly are not seeing that in the spec sheets!

Ralph,

To be clear, a current amplifier does not significantly load the cartridge. The 'zero ohms' thing that you see talked about in reference to them refers to the virtual ground with which the cartridge plays a part.

I built a spice simulation of the circuit in question and while the input Z was not 0Ω, it was low and followed the  output V / R pattern that Lewm described.  When I placed a 0.05mv 2Ω source it delivered 25µA of current into the phonoclone circuit.

I am referring to the simple fact that a stiffer cantilever will be unable to trace higher frequencies- at some point, it won't be able to follow the groove wall impressed with higher frequencies.

I believe that if a cantilever is either too stiff or too compliant it will have issues tracking high frequencies.   As for 47K being the optimal load,  I see all kinds of manufacturers suggesting values other than 47K as the optimal load for their cartridges.  

dave

I was merely pointing out that there is some merit in this idea of a "current-driven" phono stage for certain very LOMC cartridges, even though the use of the term may be semantical or to put it another way, an exaggeration.  On a practical level, I hear it.  I was maintaining a priori in my discussions with Chakster that the input impedance of most such phono stages, or phono stages that have been marketed as "current-driven" is not zero.  So I don't disagree with any of the above. The key word is "marketing". Anyway, I am quite pleased with the result.

I wouldn't worry about whether a cartridge is a voltage or current generator- the simple fact is current does not exist without voltage and vice versa. I think this might have come up on account of current amplifier phono sections, which have that low 'virtual ground' thing going on.


Just because its a current amp does not mean you need the source to make only current.

At any rate, a cartridge makes **power** since its a generator; there is voltage and current at the same time.

bydlo and larry, I wouldn't argue with what you both say, but I would point out that the capacity of a LOMC to make signal current into a very low resistance load (meaning a load that is equal to or much lower than its internal impedance) does not usually parallel its capacity to make voltage into a "high" resistance load (meaning any load that is about 10X the coil resistance). (I am not getting into the argument between Raul and Atma-sphere.) For example, my MC2000 is rated for 0.05mV at the standard stylus velocity. But its internal resistance is only 2 ohms. Thus it can generate 25uA of current into no load or probably anything much lower than 2 ohms. For comparison, my Audio Technica ART7 has twice the voltage output of the MC2000 (0.12mV) but also has an internal impedance of 12 ohms at 1kHz. Thus the ART7 is less efficient at generating current (10uA), when forced to do so, than the MC2000. Viewed this way, the MC2000 more than holds its own for current output, among very LOMC cartridges.

@lewm What you are describing is the fact that the lower output resistance of a voltage generator, the more current efficient it is. This does not change the fact that by the laws of induction MC and MM carts are both voltage generators.

atmasphere

... if you understand that a cartridge is a generator, maybe this idea is easier to understand in that a conventional generator which is spun to make electricity, the generator shaft becomes progressively harder to spin the more the generator is loaded. A cartridge **has** to have a similar behavior!

That's a great analogy! Thanks for sharing, Ralph!

rauliruegas

Dear @cleeds : " I think Ralph has been very patient with you...""

Patience?, I have years wating for his numbers about and he only showed and shows : empty words

We are off-topic. Briefly, no matter how impatient or unhappy you are, your accusations against Ralph - in particular, that he has lied in the forum - are unwarranted. The two of you seem to disagree, which is not unusual here. Yet you continue to prosecute your case with insult.

As I mentioned before, I think some of the problem here may be a language barrier. Please consider that.

My personal take on it is that the coil generates what you tell it to. Leave it open it generates voltage, Load it down it generates current.

@intactaudio 

To be clear, a current amplifier does not significantly load the cartridge. The 'zero ohms' thing that you see talked about in reference to them refers to the virtual ground with which the cartridge plays a part. Virtual ground being nearly zero ohms is **in no way** similar to actual ground!! So the cartridge does not behave as it its driving a short. It behaves as if it is driving a fairly high impedance. This may sound counterintuitive, but a virtual ground is a thing that has to do with how OpAmps work and if it was really the same thing as zero ohms, the OpAmp wouldn't work. Another way of putting this is that 'virtual ground' is a charged term in that it does not mean 'ground' at all. The word 'virtual' means something different than 'actual' :)

when you say "ability to trace" are you referring to the output generated by the cartridge or the physical ability for the stylus to remain in contact with the groove wall?

I am referring to the simple fact that a stiffer cantilever will be unable to trace higher frequencies- at some point, it won't be able to follow the groove wall impressed with higher frequencies. This point may be outside of the audio band, but the way some people try to use loading resistors as a tone control, with some cartridges I suspect it will be inside the audio band too. Regardless, by loading the cartridge in a significant manner, causing the cantilever to be less supple is unavoidable.


The reason I do not think cartridge designers design for any load other than 47K is twofold: first, 47K is the industry input impedance standard for phono preamps. Second, I had a conversation with Jonathan Carr (well known of Lyra fame) on this very topic and it was he who mentioned to me that loading at 100 ohms or the like would have the effect of reducing high frequency performance (this conversation occurred in my room at the 2014 Munich show; we had both been active on a thread on cartridge loading that can be found on the 'What's Best' audio forum). This issue was at the heart of the conversation- it was not about anything else. Now as a phono preamp designer, having this conversation with a top cartridge designer, and understanding basic physics of how transducers work, this confirmed my own work in the area. He and I are on the same page with anything to do with cartridge loading, not just the cantilever stiffness issue.

If you know how electro-mechanical transducers work, you can't come to any other conclusion. To make things easier to work with, we humans often simplify a picture so we can deal with basic concepts. Making the cartridge output invariant as if it somehow does not obey Ohm's Law and basic generator theory (see https://en.wikipedia.org/wiki/Generator_(circuit_theory)) is one of those ways of simplifying a concept.  But if you understand that a cartridge is a generator, maybe this idea is easier to understand in that a conventional generator which is spun to make electricity, the generator shaft becomes progressively harder to spin the more the generator is loaded. A cartridge **has** to have a similar behavior!