Cartridge loading explained

the thin end of the wedge
JoeE SP9
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Re: Cartridge loading explained

Post by JoeE SP9 » 15 Oct 2016 17:42

KarlBaj wrote:Astonishing how all this mingling with resistors and capacitors looks like a primitive, manual and extremely awkward way of doing exactly what is happening inside that nowadays much- maligned HiFi seperate that we were told back in the Eighties no one could live without: the equaliser.

Yes, I know:

[-X [-X [-X
No you don't. :mrgreen:

Equalizers were invented and merchandised for correcting in room response. They were not invented/intended to smooth/change the frequency response of phono cartridges. To do that we have phono preamps with variable loading.

Following a cartridges loading requirements ensures the flattest frequency response.

FWIW: I have used linear equalizers in the past and currently use a stand alone DSP to smooth in room bass response (<85Hz) in my acoustically treated room.
Last edited by JoeE SP9 on 15 Oct 2016 17:57, edited 2 times in total.

bcarso
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Re: Cartridge loading explained

Post by bcarso » 15 Oct 2016 17:51

KarlBaj wrote:Astonishing how all this mingling with resistors and capacitors looks like a primitive, manual and extremely awkward way of doing exactly what is happening inside that nowadays much- maligned HiFi seperate that we were told back in the Eighties no one could live without: the equaliser.

Yes, I know:

[-X [-X [-X
It's not as simple as that, although I have nothing against equalizers.

If there is a very strong ultrasonic resonance with an inadequately damped MC cartridge, you have the potential for overload and excessive IM distortion in the preamp. Once that spurious energy is present you can't get rid of it with post-EQ.

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Re: Cartridge loading explained

Post by KarlBaj » 15 Oct 2016 18:21

Equalizers were invented and merchandised for correcting in room response.They were not invented/intended to smooth/change the frequency response of phono cartridges.
You're absolutely right, yet it seems more than likely they were used for that very purpose, too, since 99.9 pct. of users would probably just (like me) set up these thing by ear and not know what deep down was causing the problem they were trying to rectify. Hence, from an overall point of view they would in many cases be doing the same as what today's audiophile is attempting when he solders capacitors and resistors in and out of his phono stage. If you really don't understand what I mean, just open op an equaliser and what do you see? Essentially resistors and capacitors of varying values stretching across between the signal path and earth/ground. Which is exactly what happens when you solder in and out similar components by hand, only done a lot more smartly. Am I right?
Following a cartridges loading requirements ensures the flattest frequency response.
Ergo: equalisation.

In any case, I was just trying to make a bit of a joke, hence the funny man X 3 wagging his finger.

JoeE SP9
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Re: Cartridge loading explained

Post by JoeE SP9 » 15 Oct 2016 18:35

KarlBaj wrote:
Equalizers were invented and merchandised for correcting in room response.They were not invented/intended to smooth/change the frequency response of phono cartridges.
You're absolutely right, yet it seems more than likely they were used for that very purpose, too, since 99.9 pct. of users would probably just (like me) set up these thing by ear and not know what deep down was causing the problem they were trying to rectify. Hence, from an overall point of view they would in many cases be doing the same as what today's audiophile is attempting when he solders capacitors and resistors in and out of his phono stage. If you really don't understand what I mean, just open op an equaliser and what do you see? Essentially resistors and capacitors of varying values stretching across between the signal path and earth/ground. Which is exactly what happens when you solder in and out similar components by hand, only done a lot more smartly. Am I right?
Following a cartridges loading requirements ensures the flattest frequency response.
Ergo: equalisation.

In any case, I was just trying to make a bit of a joke, hence the funny man X 3 wagging his finger.
No, you are not right. You really shouldn't make unfounded assumptions about the technical level/competency of posters here.
I'm a retired BS EE/MS Comp Sci. I used to design power supplies and low noise amplifiers used in the medical field.

I have posted before that using the recommended load in the phono preamp for a phono cartridge generally results in the flattest response. If you don't like what you're hearing then tweak your linear equalizer to your hearts content.

I have posted the RIAA curve below. Not using the manufacturers suggested values to load the cartridge in the phone preamp will result in a less than flat response.

Be advised that moving magnet cartridges are sensitive to capacitive loading while moving coil cartridges are more susceptible to resistive loading.
https://upload.wikimedia.org/wikipedia/ ... ay.svg.png

This is what's known as complimentary curves. If you add the recording response to the playback response the result is a flat line. This is how a phono preamp is supposed to react to the signal from any phono cartridge MM or MC.

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Re: Cartridge loading explained

Post by KarlBaj » 15 Oct 2016 20:21

No, you are not right. You really shouldn't make unfounded assumptions about the technical level/competency of posters here.
So it's good that I haven't.
I'm a retired BS EE/MS Comp Sci.
Don't know what that is, but I'm a retired science and music teacher myself, if that counts for anything.

Regarding irony, I know it's said that some nationalities have it in their make-up and others don't. You can't really blame anyone either way, other than if you're brought up with it and using it on someone who isn't. So I apologise, remembering what Bob Dylan said: "It's nothing. It's just something I learned over in England."

klimal
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Re: Cartridge loading explained

Post by klimal » 10 Mar 2017 06:24

Any simple tutorial on how to use the B2Spice sotware to get the cartridge's FR?

FileFixer

Re: Cartridge loading explained

Post by FileFixer » 10 Mar 2017 13:49

klimal wrote:Any simple tutorial on how to use the B2Spice sotware to get the cartridge's FR?
You can to use EasyEDA online software to get cartridge FR and plot them. It have huge base of electronic components and it is very easy to use. Also you can to view FR and Phase on plot.
https://easyeda.com/

37670

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Re: Cartridge loading explained

Post by Moving Magnet » 21 Apr 2017 10:38

Hi, started to read the first pages of this thread, very interesting so far!

Just one question. Can you notice by ear the difference between no loading and increasing steps until about 220pf? (Talking just phono stage capacitance). I tried with a friend's AT100E (recommended capacitance 100-200pf) and couldn't really notice any difference between 0,120,150,180 and 220pf...(it was done on the fly using a socket) We just left it with 180 pf wishing it would tame some brightness...

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Re: Cartridge loading explained

Post by andyr » 21 Apr 2017 12:21

My view is that if the cart mfr specifies a cart loading (like Stanton does for my model - 275pF) then you use that.

If you want to get 'picky' you can then use your ears to decide whether more or less capacitance - if you can arrange for these differences - sounds better ... or worse. :D

Modelling the cart in some sim program is suspect to me ... because you never know whether your 'model' represents the real thing ... or not.

Andy

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Re: Cartridge loading explained

Post by Moving Magnet » 21 Apr 2017 14:48

Thanks Andy, in this case 4 ears couldn't discern anything! In any case i believe the amp's phono stock input capacitance is 150uf, so i'd say 180uf won't make much difference for the better or worse...

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Re: Cartridge loading explained

Post by Moving Magnet » 21 Apr 2017 15:51

180uf that would make a total of about 280uf cables included

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Re: Cartridge loading explained

Post by Moving Magnet » 22 Apr 2017 12:07

And something relevant, it seems Audio Technica cartridges recommended capacitance refers only to that value in the phono stage section, not cables included! Until know I thought it was cables included, and it seems most of the poeple think that as well? I read this in another forum from someone who had direct correspondence with AT personnel.

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Re: Cartridge loading explained

Post by andyr » 22 Apr 2017 12:20

Moving Magnet wrote: And something relevant, it seems Audio Technica cartridges recommended capacitance refers only to that value in the phono stage section, not cables included! Until know I thought it was cables included, and it seems most of the poeple think that as well? I read this in another forum from someone who had direct correspondence with AT personnel.
That is very interesting - if confusing - bcoz the cart doesn't care where the capacitance it sees, comes from ... it simply 'responds' to the total amount of capacitance delivered by:
1. the headshell wiring
2. the arm wiring
3. the phono cable, and
4. the default on the phono stage PCB.

Maybe AT takes an average sum of 1, 2 & 3 and then quotes the value for #4 which will get the total into the right ballpark?

Andy

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Re: Cartridge loading explained

Post by Laila1 » 22 Apr 2017 15:08

Hi Andy,

I really don't think that . . . for example the cabling on my Technics are 90 pF and the cabling on my Jelco are 235 pF. To much difference to make sense, I think.

/ Lars

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Re: Cartridge loading explained

Post by andyr » 22 Apr 2017 22:37

Laila1 wrote: Hi Andy,

I really don't think that . . . for example the cabling on my Technics are 90 pF and the cabling on my Jelco are 235 pF. To much difference to make sense, I think.

/ Lars
That's quite a difference! Which means what someone posted about AT specifying just the phono stage capacitance ... doesn't make any sense. :D

Andy

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