Nagaoka carts true compliance figures?

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panum
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Nagaoka carts true compliance figures??

Post by panum » 19 Jan 2010 20:37

As I have been now advised at other topic and two different web pages that Nagaokas compliance figures are much higher than the specs say. Caused by different measuring methods. So would somebody calculate the real compliance figures for these cart, would Help a lot

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

http://db.audioasylum.com/cgi/m.mpl?for ... compliance

lini
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Post by lini » 20 Jan 2010 02:41

You can also use recommended tracking force (or the median of a recommended tracking force range) as an additional indicator, if you've only got a compliance spec without further qualifiers or even none at all. Similar to doubling a "dynamic compliance at 100 Hz" value for an estimation at 10 Hz, this also isn't quite exact, but it's usually good enough as well to decide, whether trying a cart/arm combo makes sense or not...

Greetings from Munich!

Manfred / lini

krenzler
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Post by krenzler » 20 Jan 2010 19:53

Yeah dynamic lateral compliance at 100Hz multiplied by a value between 1,5 -> 2 to get at the same at 10Hz.

Or approximately dividing the static compliance by 2.

http://www.moerch.dk/files/Cartridge%20 ... 20List.pdf

"There is one snag about it. The manufacturers of cartridges do not always state a useful value for C. (It should be started at 10 Hz). Figures of C coming from Japan usually are measured at 100 Hz, so they should be multiplied by 1.5-2. Figures of C coming from USA often are static values, so they should be halved. Most figures of C coming from Europe are OK (stated at 10 Hz) Also the tracking force could be used, as this usually is a function of the compliance."

Axon
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Post by Axon » 20 Jan 2010 22:54

People say this about the AT-OC9 too. LIEZ. ;) The stated compliance is 35cu, and when I've measured it with HFNRR - ignoring the voice and looking at the wow/flutter, mind you - I come up with a measured compliance of about 32cu.

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Post by krenzler » 21 Jan 2010 15:06

The stated 35cu is the static compliance.

Axon
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Post by Axon » 21 Jan 2010 19:06

It's also the dynamic compliance at ~10hz.

Guest

Post by Guest » 21 Jan 2010 19:45

Good job and I think it figures. Isn't it both difficult to achieve and undesirable from a response perspective to have frequency dependant compliance ?

lini
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Post by lini » 21 Jan 2010 21:50

ld: Difficult to achieve? Uhm - why should it? I'd assume wiggling a cantilever in an elastomer suspension to be similar to moving a spoon in a honey pot. But not all suspensions are equal, hence doubling the 100 Hz compliance or halving the static compliance sometimes are only pretty rough estimations. That's why I'd suggest to look at the recommended tracking force as well, 'cause that can also Help to zero in on the 10 Hz compliance...

Greetings from Munich!

Manfred / lini

lini
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Post by lini » 22 Jan 2010 03:44

Frequency dependant compliance? What in the world are you talking about?
Well, it wouldn't be different from 10 Hz at 100 Hz, if it wasn't frequency dependant, would it?

Greetings from Munich!

Manfred / lini

krenzler
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Post by krenzler » 22 Jan 2010 05:53

Axon:

Are you referring to the lateral or the vertical resonance test?

At what frequency was the stylus tip most excited?

What tonearm are you using?

Werner
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Post by Werner » 22 Jan 2010 08:23

Recently measured by Paul Miller (HFN):

Audio Technica AT-OC9ML/II

LF Resonance in 8g tonearm
Arm/Cartridge Resonance = +9dB @ 10Hz (Vertical)
Arm/Cartridge Resonance = +14dB @ 7Hz (Lateral)

That puts the horizontal compliance at 30 cu, and the
vertical one at 15 cu.


While we are at it:

Denon DL-103R

LF Resonance in 8g tonearm
Arm/Cartridge Resonance = +8dB @ 18Hz (Vertical)
Arm/Cartridge Resonance = +9dB @ 11Hz (Lateral)

12 cu horizontal, 4.5 cu vertical.

Guest

Post by Guest » 22 Jan 2010 10:31

lini wrote:ld: Difficult to achieve? Uhm - why should it? I'd assume wiggling a cantilever in an elastomer suspension to be similar to moving a spoon in a honey pot. But not all suspensions are equal, hence doubling the 100 Hz compliance or halving the static compliance sometimes are only pretty rough estimations. That's why I'd suggest to look at the recommended tracking force as well, 'cause that can also Help to zero in on the 10 Hz compliance...
Hmm. Spoon in a honey pot is not springy, that's drag, a measure of damping factor. Damping force is proportional to velocity and therefore naturally varies with frequency for any given amplitude.

BUT damping factor is not compliance.

Compliance is a function of the spring constant of the suspension i.e how springy it is, how much force resists compression or extension. So for compliance, spring force is proportional to amplitude (compression or extension dimension) which in principle is independant of velocity and hence independant of frequency. It would be hard to make a spring with a frequency dependant compliance, it's not natural !

Unless compliance is non-linear (which would be bad), compliance should also be independant of VTF.

Different lateral and vertical compliance is a different proposition. It simply means a different spring constant in vertical and lateral planes, so would be readily achievable with an asymetric profile for suspension material, for example. But that's not frequency dependance !

Here's a plot I recently made (for different purposes) that shows vertical and lateral resonances being very similar on an OM2 Red. But that depends on cartridge type, and where it varies it is usually specified. Just for interest, and illustrates how easy it is to see the resonance peaks from a normal recording without a test disc.
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Post by missan » 22 Jan 2010 17:05

It´s a bit odd that Pramanik speaks of compliance as frequency dependent, in Klaus paper. He speaks most likely of the dampening parameter of the elastomer.

I would imagine that in most cases the compliance is really the same vertically and laterally for most cartridges. One test is valid for that specific condition.

As ld says, there is no need for a test record, the resonances will show up in a frequency plot.
missan

TA

Post by TA » 22 Jan 2010 19:06

Sometimes perhaps the resonance also reflects RIAA/preamp roll-off. Care must be taken when intepreting.

lini
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Post by lini » 22 Jan 2010 19:42

ld: I think that's why we have the difference between static and dynamic compliance. In a static system, the exciting force is constant, so the basic springiness rules apply (although I could still very well imagine that the resulting static compliance is only linear within a certain range, depending on the shape and material of the suspension...). Whereas in a dynamic system that exciting force varies over time, so it would seem logical to me that we have to do with a mix of springiness and damping effects.

Greetings from Munich!

Manfred / lini

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