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In Reply to: RE: Frequency range: 20Hz - 70 kHz. What's the point of........ posted by Rick W on September 19, 2014 at 09:13:29
It prevents phase shift from occurring in the audible frequencies. That is always the point of components having extended frequency response above the audible range. This is why moving coil cartridges sound better than moving magnet cartridges.
Follow Ups:
You've included many things that affect the sound, what about the (common) transformer that seemingly most use?
Serving up content-free posts on the Internet since 1984.
Well, my Bob's Devices 1131 sounds outstanding to me. It's my favorite SUT. ;-)
Objectively speaking, that phase analysis is incorrect. Frequency of primary phase shift is defined by mechanical and electrical properties. With MCs, the shift is caused by mechanical resonance and the peak is only extended in frequency by mechanical damping. Electrical resonance in no way defines MC phase performance.
Electrical resonance does lower the high frequency resonance peak of a high inductance cart and phase nonlinearity can extend as low as 1KHz, but not necessarily. Some MMs, especially those with boron or beryllium cantilevers resonate close to 30KHz. If such a cart, like some AT/Signet, have extremely low inductance (85mH), phase performance will be better than some MCs.
Ortofon actually measured phase performance with their MC200 and 5 unnamed MMs. This is the only known measurement of phase vs amplitude. If someone else measured this with different results, please let me know.
The MC200 has a boron cantilever and high frequency resonance is at 27K.
That is the frequency of both mechanical resonance and phase shift peak. Damping extends the phase peak to higher frequency, but it also extends nonlinearity lower in the audio band. With stock damping the MC200 phase nonlinearity extends down to 7 or 8KHz.
There is not necessarily a steep roll-off in MM response just beyond electrical resonance. This was shown unequivocally in measured performance.
I think too much is being made of phase performance and it's not the reason some prefer MCs. The Lyra Kelos and Atlas (well respected) both have primary high frequency resonance at 20K, so phase performance will mimic many MMs. This seems to be a deliberate by design.
In the middle of this page is a reprint of the article, Phase Testing in Phono Cartridges. 4 MC plots are on the right and 5 MM plots on the left. If you magnify it you might be able to read the commentary:
BIRD LIVES
Instead of constantly badgering me about this, why don't you go badger Jim Hagerman. All I did was expand on Jim Hagerman's electrical model and as far as I'm concerned, there's nothing wrong with his model or my analysis. However, if there is something wrong, go tell Jim Hagerman. He is the one who developed the model. However, I seriously doubt you actually understand much of anything you're talking about and I seriously doubt that my analysis of Jim Hagerman's electrical model is incorrect. You are the only person who has ever complained and based on your argument, I don't think you understand electrical theory.
Good luck,
John Elison
Hagerman isn't posting misinformation, you are. His electrical model is correct even though it's of limited use for loading a MM. Your expansion of his electrical model is pure conjecture and ignores the fact of mechanical performance.
How can you argue your theoretical model against measured performance? It's absurd.
Below is a link to a thread on VE about loading. CarlosFM (EE) started the thread and Werner (EE) chimes in on page 5. If you read some of it you'll see that Hagerman calculator doesn't work for real world carts.
Phase is another question and until you can prove otherwise, I'll accept Ortofon's measurements over conjecture.
BIRD LIVES
> Hagerman isn't posting misinformationIf Hagerman isn't posting misinformation, then neither am I. You can't have it both ways. Sorry!
Better luck next time, although I hope there isn't a next time.
Goodbye,
John Elison
Edits: 09/19/14
**If Hagerman isn't posting misinformation, then neither am I. You can't have it both ways. Sorry!**
Hagerman's electrical resonance model is valid only in the electrical realm. It's useless for loading purposes because it ignores the mechanical aspect. Your Hagerman extension makes the same mistake. Here's what Werner (the same Werner who wrote the TNT article Load the Magnets) had to say about the Hagerman calculator and a Spice loading program differences:
folkdeath95 wrote:
**Hello,
The Spice simulation program that CarlosFM used, seems to differ somewhat from the Hagtech results.**
Werner wrote:
**And both are near-useless as they don't take the (inevitable) cartridge's mechanical resonance and treble losses into account. With MMs this is all happening around 10-20kHz, and electrical resonance (through loading) is used to compensate for this.
Mechanical resonances and mechanical treble losses (how fast can you wiggle a given mass?) don't show up in electrical models of cartridges. Both phenomena happen between 10 and 20kHz with MM cartridges.
Sadly cartridge manufacturers don't publish the electrical equivalents
of their products mechanical properties.**
I don't expect you to accept Ortofon's MEASURED phase response. I offered to email the PDF to you and I got no response. I post this once again for those interested in this subject.
Regards,
BIRD LIVES
> Hagerman's electrical resonance model is valid only in the electrical realm.
You are absolutely right. My model is valid only in the electrical realm, too. I've been trying to tell you that for years. However, the thing that matters is that high inductance cartridge have their electrical resonance within the audible range between 10-kHz and 20-kHz, and this causes audible problems regardless of how their cantilever mechanical resonance interacts. Low inductance moving coils do not have an electrical resonance to contend with until you get into the megahertz region. Consequently, their cantilever mechanical resonance can be dealt with by using stiffer cantilevers to move it out of the audible frequency range. The mechanical cantilever resonance of the Dynavector 17D3 is 80-kHz, which removes if from audible frequencies. In fact, just about all moving coil cartridges have their mechanical cantilever resonance well above 20-kHz so it does not fall into the audible range. The reason that low-output moving coils have a rising frequency response in the high frequencies is because their mechanical cantilever resonance is purposely under-damped in order to reduce phase shift within the audible range. Ortofon was able to manufacture moving coils that exhibited very little phase shift within the audible frequency range by under-damping the cantilever mechanical resonance and moving the electrical resonance out beyond 1-MHz. This is what makes low-output moving coils sound better than high-inductance moving magnets.
Goodbye again,
John Elison
PS. There will be absolutely no difference between a Spice analysis of Hagerman's electrical model and my electrical analysis. As long as you use the same electrical model, there can be no difference unless Spice is designed incorrectly, and I seriously doubt that is the case.
** My model is valid only in the electrical realm, too.**
But it isn't. In the case of a cartridge with almost no inductance (LOMC), phase shift is defined completely by mechanical properties, not electrical. This is clearly shown by Ortofon, but you refuse to look at it. An undamped MC200 w/boron cantilever has primary phase shift occurring at 27KHz not somewhere in the stratosphere.
> Typically, the undamped moving coil cartridge has response which begins to rise in the 5 to 6KHz region, climbs to + 8dB at 20KHz, and peaks at about 15 to 18dB at 25 to 28KHz. This undamped cartridge also has a large amount of phase shift, up to 180° centered around the resonant frequency. <
Regards,
BIRD LIVES
> But it isn't.
It has to be; it's not really my model; it's Hagerman's model. I copied it. Go bother Jim Hagerman and leave me alone.
Good riddance,
John Elison
What are those audible problems? I asked earlier and you apparently thought I was being argumentative. I wasn't, it was simply a serious question. I'd like to know what the aural/audible manifestations of the phase shift you're talking about are.
Phase shift is a time distortion and it varies with frequency. In this case the distortion is plus. As it's plotted, it peaks at high frequency resonance where the shift approaches 180°. The shift diminishes on either side of that peak and will eventually go to zero.
Ortofon used their MC200 as an example, saying that undamped it had spectacular imaging, but was unlistenable due to excessive brightness. Damping was required and imaging suffered the more damping was applied.
This analysis is looked on with some suspicion. It could be the rising amplitude response that caused the spectacular imaging or a combination of those two. Imaging is the only aspect of performance alluded to.
neo
BIRD LIVES
I don't hear timing issues with my mm's, all of which have pretty good imaging. I'm more concerned about realistic timbre anyway, and if there's an effect on timbre due to phase issues that my carts have I'm not hearing it. 'Course my whole system is far from SOTA.
Edits: 09/20/14
I'm keeping it secret. The only way you'll ever know is to make your own comparison.
Good Riddance,
John Elison
nt
Here's freq. res. specs for 2 of my carts - they ain't mc'sGrado Master Reference: 10Hz - 60kHz (Statement series go to 75kHz)
AT ML170: 5Hz - 40 kHzMy other 2 carts - both mm's - don't go past 20kHz and phase shift or no, I prefer them to mmany of the mc's I've heard. As you know, I ain't alone.
Without spending too much time looking more mm's up......
Ortofon 2M Black: 20Hz-31kHz
AT150mlx: 10Hz-30kHz
ADC XLM: 15Hz-24kHz
Grace F9 - according to Vinyl Engine above 60kHz
Music Hall Mojo: 20Hz-27kHz
Nagaoka MP-500: 20Hz-25kHz
Pickering XSV 3000: 10Hz-30KhzBearing in mind my technical ignorance, can you explain in terms I might understand how high freq. response in carts prevents phase shift and what the audible effects of phase shift in carts w freq. res. to only 20kHz are? In other words what are the tell tale signs of phase shift I'm supposed to be hearing with my mm's that don't go past 20kHz? Also, how high does freq. response need to go to prevent those "symptoms"?
If what you're saying is true, apparently phase shift doesn't bother me anywhere near as much as what I perceive to be the UNnatural sound of many mc's. I do really dig Koetsus though :-)
Edits: 09/19/14
Phase shift will be present a full decade below the -3db point. If the -3db point is 40kHz then the phase will be shifted all the way down to 4kHz.
It takes a -3db point of 200kHz to give 20kHz phase shift free.
To my ears, when there's phase shift in the audio band the HF is just not as "open" sounding.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
has some info on modeling the mechanical parts of an MM cartridge. The same principles apply to MC except the final model will have very different values :) (in most cases)
dee
;-D
True terror is to wake up one morning and discover that your high school class is running the country.
quote by Kurt Vonnegut
will give you all the answers you want about each one the specific cartridges, you JUST have to create a unified model of the mechanical portion and the electrical portion of the entire cartridge, and include the loading of the cable and the preamp. You will find surprising things about all of them. and loading will not only effect the electrical motors but the mechanical damping of the entire system. The article pointed by John is good, but way to generic and paints a picture with a broad brush stroke. The statements made about the characteristics of each motor type are generally true, then there are the exceptions that break that rule. BTW the frequency limits do not mean that there are no phase shifts a lot earlier in the circuit, and some people may be more sensitive to it than others.So you have to take it all with extreme prejudice, and only accept what you hear. The measurements and electrical character of the cartridge give a good starting point to orient yourself to what to expect, and then be confirmed or surprised :). This is what makes this such an interesting hobby.
dee
;-D
True terror is to wake up one morning and discover that your high school class is running the country.
quote by Kurt Vonnegut
Edits: 09/19/14 09/19/14
"So you have to take it all with extreme prejudice, and only accept what you hear. The measurements and electrical character of the cartridge give a good starting point to orient yourself to what to expect, and then be confirmed or surprised :). This is what makes this such an interesting hobby."
In spite of my post above, I totally agree with you.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Here is a link that you may find helpful.
John should have probably clarified the difference between high and low impedance MMs, but otherwise the reason is that high impedance MM cartridges have a large inductance which causes an electrical resonance well within in the audio passband. Low impedance MMs like Pickering XLZ or Stanton LZS have a low impdeance of 1mH, but at the MC load impedance of 100 ohms, the electrical resonance still occurs at a very low frequency compared to LOMC. With my Stanton LZS, I get a much better sound with a load resistance of 4.7kohm that is close to LOMC - there is much greater realism and a more palpable soundstage than with the high impedance version. High impedance MM always seems to have a slight colouration (which disappears largely with the low impedance body).
For conventional MM, the designer chooses an inductance and coil resistance such that he gets a resonance (and suitable damping) with the phono stage capacitance and resistance on the input at a particular frequency which compensates for the mechanical resonance of the moving assembly. When done appropriately, you ideally get a maximally flat wide response.
Have a play with the calculator on the web page and see for yourself.
Regards Anthony
"Beauty is Truth, Truth Beauty.." Keats
Hey Rick,Feel free to spend all the time you need to look up specs on different cartridges. Then feel free to study electricity and electronics so you won't be so ignorant in the future. Electricity is quite an interesting subject. There is much written about frequency response and phase shift so feel free to knuckle down and dig in. You'll feel much better about yourself and you won't have to second guess whether or not I'm giving you correct information.
Good luck,
John Elison
Edits: 09/19/14
John I have no intention of getting in a debate with you or anyone else about the merits of moving coils vs. moving magnets. With you, especially, it would be like me bringing a knife to a gun fight.
However, all I can say with any authority is that in my system, in my room, there is something very seductive about the sound of especially some vintage moving magnet cartridges, such as the Grace F9 (which, based on Vinyl Engine specs, goes up pretty high in bandwidth.)
I have, as you know, a DLS1 and it does sound very good indeed, when properly loaded, etc.
But I have, of late, been listening to both the Grace and a Nagaoka MP 500 and the urge to replace either of them with the DLS1 has been so infrequent as to be meaningless.
But it may be that happy listening is because of limitations of my system, or hearing, or both.
And, if I may, I seriously doubt the major manufacturers' seeming lack of interest in further development of the moving magnet is science-driven.
> And, if I may, I seriously doubt the major manufacturers' seeming lack of interest in further development of the moving magnet is science-driven.
What do you think is the reason?
There is more money to be made with moving coils...right now, than with moving magnets.
Sound Smith and Grado, both slightly above "boutique" level companies are the exception, and it is interesting that both seem to have been interested in significant development of moving iron cartridges and not moving coil.
Yes, Ortofon and Clearaudio offer relatively expensive moving magnet cartridges, but Clearaudio is said by many apparently knowledgeable folks to buy their generator assemblies from a large Japanese manufacturer.
One would assume the big outfits' marketing folks are watching Sound Smith's sales with some interest.
So, the short answer is the lack of development among the big boys is market driven.
Hey John, feel free to study music and learn how to play several instruments so you won't be so ignorant about what you're listening to on your Tech. 1200. Music is actually quite an interesting subject. Who knows, your ears might eventually develop.
Thanks, Rick.
I have studied music and I am a musician although I haven't played in years. You're definitely right that music is an interesting subject. I certainly hope my ears don't develop to the extent of yours because I don't own any moving magnet cartridges.
Best regards,
John Elison
nt
Thanks for that, John.
I will be sharing this with my "oh-so-technical" guitar buddy whose just getting (back) into LPs now (and starting with a Clearaudio Concept table- not a bad start from nothing since about 1990, I'd say!). He likes to compare the sound AND specifications... What a mess!
Dman
Analog Junkie
Its the transparency and clarity of the MC that got me. Lots of MMs are great. My favorite from back in the day was a MI actually, an ADC XLM II Improved. I have a NOS one of these plus a Shure Ultra 500 with a Jico SAS stylus.
I currently have the Shure mounted on my tonearm and its a superb cartridge but its missing that transparency that I'm used to with my LOMC.
I'm not certain if that's the cartridge or a fault of the MM phono preamp so I'll reserve comment until I'm done checking these out. I will give the Shure and ADC a chance.
I have a feeling it will end up the same and I'll prefer the LOMC but you never know.
Ed
We don't shush around here!
Life is analog...digital is just samples thereof
I think i would like to hear the Voice from SS, I am right now listening to the Decca Gold, and a Technics EPC 100 MK 4 would be nice to hear :). The Decca is very dynamic, transparent, but i think it is coloured (in a british way) sounding. Maybe it is that i do not have a POD just the plastic holder.
if all of those have artifacts that i do not like compared to LOMC, then i can write the moving magnet moving iron crowd out of my wish list.
dee
;-D
True terror is to wake up one morning and discover that your high school class is running the country.
quote by Kurt Vonnegut
I've been very impressed with the Nagaoka MP-150.
Opus 33 1/3
after all i am married...or was there something else you had in mind with a model number attached?I think i have an MP-150 floating around here...maybe i should plop it in a shell and listen to it.
dee
;-D
True terror is to wake up one morning and discover that your high school class is running the country.
quote by Kurt Vonnegut
Edits: 09/19/14
Try the MP-150. You'll like it.
Opus 33 1/3
you have more experience....
dee
;-D
True terror is to wake up one morning and discover that your high school class is running the country.
quote by Kurt Vonnegut
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