Cartridge loading explained

the thin end of the wedge
mrw00ds
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Re: Cartridge loading explained

Post by mrw00ds » 23 Apr 2017 09:44

I can only speak from recent experience,

viewtopic.php?f=19&t=95312

but the improvement I'm experiencing by reducing the 220pf capacitance load of the Cambridge Audio 651P down to 33pf to suit the Goldring 1042 is amazing. Lovely smooth sound which doesn't shout at me all the time. There's just a smidgen of lower HF/upper mid "honk" and a lack of ultimate sparkle on cymbals, triangles and stuff, so I'm going to experiment today by soldering in another 33pf per channel.

A lot of cartridge specifications don't include capacitance loading. Thanks to the knowledgeable people at Vinyl Engine I was able to sort out the problem

Moving Magnet
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Re: Cartridge loading explained

Post by Moving Magnet » 23 Apr 2017 17:18

edit
Last edited by Moving Magnet on 23 Apr 2017 17:20, edited 1 time in total.

Moving Magnet
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Re: Cartridge loading explained

Post by Moving Magnet » 23 Apr 2017 17:20

andyr wrote:
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
It does make sense to me in the case of AT. It seems a total capacitance of 100-200uf is not the case for the average user in most cases, at least without surgery or special cabling... Anyway, here's where I got this information from:

http://forums.stevehoffman.tv/threads/a ... st-9963319"]Audio-Technica AT150MLX review

HaroldNotTheBarrel
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Re: Cartridge loading explained

Post by HaroldNotTheBarrel » 29 Apr 2017 15:02

Audio-Technica recommends 100-200 pF for their best models, at least. They knew exactly what they were doing: total capacitance is all wiring + inherent value of preamp. Very low values in reality do get the best out of the carts.

Furthermore, I´ve been experimenting with very low both capacitance and impedance values, app. total 120 pF + 30 kOhms and my AT-ML180/OCC does benefit from very low values, sounds now better than ever has. The same goes with SHURE V1V-MR w/original stylus as well.

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Re: Cartridge loading explained

Post by wojo58 » 30 Apr 2017 15:34

I know this is pitifully late to the party, but just how exactly does one measure inductance, capacitance and impedance, specifically how they apply to TTs? If I remember from some old electronics classes, these are "active" measures versus the static measures of resistance, voltage, and current.

A tinkering I must go....... :wink:

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Re: Cartridge loading explained

Post by wojo58 » 02 May 2017 02:20

Ah, the dulcet sound of crickets........

I guess if I had to ask, it shouldn't bother me :roll:

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Re: Cartridge loading explained

Post by LeonW » 02 May 2017 21:28

There 4 options on my phono stage, the lowest being 120pf, then 220, 340 & lastly 440pf.

I seem to recall the packaging on my cart recommended anywhere between 150pf - 300pf so I set it the middle at 220pf however after a tinker I found 120 sounded much more to my tastes. Horses for courses?

andyr
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Re: Cartridge loading explained

Post by andyr » 03 May 2017 00:07

LeonW wrote: There 4 options on my phono stage, the lowest being 120pf, then 220, 340 & lastly 440pf.

I seem to recall the packaging on my cart recommended anywhere between 150pf - 300pf so I set it the middle at 220pf however after a tinker I found 120 sounded much more to my tastes. Horses for courses?
I suggest that's bcoz when you add the capacitance of the headshell/arm/phono cable wiring, you will end up with 220pF ... whereas when you use the 220pF setting on your phono stage, you will have a total capacitance of 320pF.

Andy

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Re: Cartridge loading explained

Post by Tympani1982 » 09 May 2017 08:18

Is there really a specific capacitance or impedance (resistance) loading for a specific phono cartridge? It seems to me it has to be a range, probably a fairly wide recommended range rather than a specific number.

The frequency response curve of every speaker system can be very different. Some might have an elevated treble and some might be slightly dimmed in high notes. I understand that the tweaking of cartridge's loading has the effect of raising or lowering the treble. Isn't that the tweaking has a dependency on the speaker's frequency response curve? So the tweaking can be different from one system to another.

In other words, a 200 pf input capacitance may be right for you but for my system I might need 100 instead. Am I mistaken something here?

andyr
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Re: Cartridge loading explained

Post by andyr » 09 May 2017 11:44

No, I think there's a lot going for your posit. :D

By mentioning capacitance, you are explicitly talking about MM carts but, yes, MM cart manufacturers often state the optimal C-loading (or C-loading range) ... but, as you mentioned, your speaker's response will affect this.

Likewise, where in the recommended R-loading range is your preference, if you have a LOMC cart, is your decision.

Andy

TA

Re: Cartridge loading explained

Post by TA » 09 May 2017 18:24

Tympani1982 wrote:Is there really a specific capacitance or impedance (resistance) loading for a specific phono cartridge? It seems to me it has to be a range, probably a fairly wide recommended range rather than a specific number.

The frequency response curve of every speaker system can be very different. Some might have an elevated treble and some might be slightly dimmed in high notes. I understand that the tweaking of cartridge's loading has the effect of raising or lowering the treble. Isn't that the tweaking has a dependency on the speaker's frequency response curve? So the tweaking can be different from one system to another.

In other words, a 200 pf input capacitance may be right for you but for my system I might need 100 instead. Am I mistaken something here?
No, ideally there should not be no such tweaking specific for the loading - if so that tweaking option should be there for all sources. The cartridge maker tries to make the response as linear as possible given a nominal load. As everyone knows, the results differ between cartridges, from small to rather large. So there is an opportunity to make a custom load to fit each cartridge.

If there is a tweaking that has to be made due to nonlinear frequency response of the speaker, one can change the speaker to a better one, work with the acoustics or use tone controls. Then it would work better with the various sources (CD, radio, tape, streaming music, LP....)

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Re: Cartridge loading explained

Post by Tympani1982 » 13 May 2017 06:34

wrote: If there is a tweaking that has to be made due to nonlinear frequency response of the speaker, one can change the speaker to a better one, work with the acoustics or use tone controls. Then it would work better with the various sources (CD, radio, tape, streaming music, LP....)
No speaker system is linear in frequency response. Some are brighter, some warmer, some sweeter and some..., you name it. None is necessarily better than any other. It all depends on individual's taste. So the tweaking in input capacitance is a valid process to optimize the sound. It is not necessarily a has to be made tweaking but nowadays it seems everyone is talking about and doing it. People change speakers for other reasons but not for this one.

TA

Re: Cartridge loading explained

Post by TA » 14 May 2017 00:48

Tympani1982 wrote:
wrote: If there is a tweaking that has to be made due to nonlinear frequency response of the speaker, one can change the speaker to a better one, work with the acoustics or use tone controls. Then it would work better with the various sources (CD, radio, tape, streaming music, LP....)
No speaker system is linear in frequency response. Some are brighter, some warmer, some sweeter and some..., you name it. None is necessarily better than any other. It all depends on individual's taste. So the tweaking in input capacitance is a valid process to optimize the sound. It is not necessarily a has to be made tweaking but nowadays it seems everyone is talking about and doing it. People change speakers for other reasons but not for this one.
Well, personal taste is a different matter. Speakers are different and some have more linear response than others. What I am saying is that if you would have a dull speaker all sources will sound dull if the sources have the same frequency response. Raising the treble in vinyl playback by changing the loading of the cartridge will help vinyl playback only, all other sources will still sound dull.

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Re: Cartridge loading explained

Post by muskrat1954 » 11 Apr 2018 04:27

I bought a cap meter a few months ago. Relative to cart loading, I measured my cables. The lowest I had were an 8" pair that I bought for my tt and some ratshack 3', middle of their line, 20+ yo. These measured 50pf. Others I had or acquired were 100 to over 600pf. So I would say cables as tone controls is a valid concept. I'm moving so things are packed away, but the cost or thickness seemed to have no correlation with measured capacitance.

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Re: Cartridge loading explained

Post by andyr » 13 Apr 2018 18:42

muskrat1954 wrote: I bought a cap meter a few months ago. Relative to cart loading, I measured my cables.
I presume you measured your phono cable's capacitance - as that is the only one that is relevant to a cart?
muskrat1954 wrote: I bought a cap meter a few months ago. Relative to cart loading, I measured my cables. The lowest I had were an 8" pair that I bought for my tt and some ratshack 3', middle of their line, 20+ yo. These measured 50pf. Others I had or acquired were 100 to over 600pf.
Yes, cable capacitance can vary considerably!
muskrat1954 wrote: So I would say cables as tone controls is a valid concept.
Yes it's a valid concept - but I suggest it's not ideal to do this (use cable capacitance as a tone control).
muskrat1954 wrote: the cost or thickness seemed to have no correlation with measured capacitance.
I can well believe this - which is why I make all my cables! :D (so I know what their capacitance (and for speaker cables, inductaance) is.

Andy

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