Cartridge compliance and arm mass confusion.

[Bonky]

I'm a little confused here (not hard I assure you...).

I'm looking for a new cartridge to pair with my Roksan Nima unipivot arm. At present I have an AT-05MC.

I've heard great things of the Dynavector 10x5, but am aware one must match the cartridge's compliance with the arm's effective mass.

In this case the Nima's EM is 10g, which according to Ortofon is 'Low Mass'. (See: http://www.ortofon.com/support/cartridgetonearm-resonance-frequency). However, according to this site: (http://www.10audio.com/roksan_v_nima.htm); it's 'medium mass'. So which is it?

Ortofon have recommended cartridges in the range of 20 to 25+ µm/mN for my set-up.

("2M Blue is a moderate compliance cartridge of 20 µm/mN, this value is within the recommended range for low mass arms.
2M Bronze will apparently be even better for your arm due to a slightly higher compliance 22 µm/mN.")

Yes I know these are MMs not MCs, but the principle is the same.

Now here's my other problem. There are many hi-fi sites that actually recommend the 10x5 with the Nima arm. However, the10X5's compliance appears to be not within the above range (or higher) at all, being 12 x 10-6 cm/dyn.

(Confusing when different manufacturer's quote using different nomenclatures/units. I believe, however, that the two are comparable - i.e. -the numbers remain the same.)

So, in theory, the 10X5 should not work particularly well in the Nima arm...

Can anyone help, a) with some common sense re EM vis-a-vis Compliance, and b) whether the 10x5 would suit the Nima, and c) any other recommendations?

Thanks,

BW

Bonky

[Rare Bird]

Nima isnt that low mass around 10g.. The 20-25x youve been recommended should be fine.

[Barry]

Hello Richard,

Looking at the Dynavector web site, the compliance of the 10x5 is 12x10-6 cm/dyne, and it has a mass of 7.3g.

The Japanese tend to quote the compliance measured at 100Hz. Ideally it should be measured and quoted at ~ 10Hz, where it has a value 1.5 - 2.0x the value at 100Hz.

The resonant frequency is calculated as 1/(2*pi*sqrt(total mass*compliance)).

Thus with a total mass of 10g (for the arm) + 7.3g (for the cartridge) + 0.5g (for the fixings) = 17.8g, the resonant frequency will be 7.7 - 8.9Hz. This is on the low side, ideally it ought to lay in the range 8 - 12Hz, however unless you use a deck with particularly bouncy suspension, you ought not to have any problems.

[nat8808]

'low mass' 'medium-mass' potato potaaato.

It's 10g EM ! - numbers are better than ambiguous words sometimes.

Yes, have to be wary of compliances being stated at different frequencies - have to make sure you're using the right number if you can get it.

Many people won't worry too much about what is perfect and will just listen .. sounds like people have tried the Nima / 10x5 combo and like it. As long as those are people who's ears and taste you trust, I'd give it a go..

[rusty bearing]

Try the ubiquitous vinyl engine calculator

http://www.vinylengine.com/cartridge_resonance_evaluator.php

[Bonky]

Thanks everyone. I feel more confident that the 10X5 would be OK.

It's such a complex subject that I wonder whether Barry and/or others could write it up as a 'sticky'?

Thanks again,

Richard/Bonky

[Wakefield Turntables]

Try the ubiquitous vinyl engine calculator

http://www.vinylengine.com/cartridge_resonance_evaluator.php

This just goes to google??

[Barry]

This just goes to google??

Yes, Vinylengine blocks all direct links from this forum. (Sour grapes?)

Anyway, it won't come up with any different result, as it uses the same formula (as it must).

[Barry]

Thanks everyone. I feel more confident that the 10X5 would be OK.

It's such a complex subject that I wonder whether Barry and/or others could write it up as a 'sticky'?

Thanks again,

Richard/Bonky

Well I must admit I have gone through this exercise several times in the past for members.

We are considering providing a 'calculator' for AoS along the lines of that provided by the vinylengine. When it materialises it will be put into The Knowledge.

Until such time, I could perhaps write up something and persuade the Admin to make it a 'sticky'.

[rusty bearing]

Yes, Vinylengine blocks all direct links from this forum. (Sour grapes?)

Anyway, it won't come up with any different result, as it uses the same formula (as it must).

By Jove so it does! Sorry chaps I had no idea, as to why.......?

[OneyedK]

http://www.vinylengine.com/cartridge_resonance_evaluator.php

Copy and past into another browser tab ;)
Actually, it's this forum software that blocks links to VE.

[Rare Bird]

My Arm cart are near as perfect match as i want..

[The Grand Wazoo]

Actually, it's this forum software that blocks links to VE.

No sorry, you are misinformed - the road-block is at VE's end.

[OneyedK]

No sorry, you are misinformed - the road-block is at VE's end.
Ah, ok, sorry...
But the "code" workaround works èh :)

[nat8808]

I say suck it and see... just as any other combo of equipment.

Funny how even die-hard subjectivists would say it is ok to study the specs to inform your choice of cartridge but not so for anything else.

[OneyedK]

Funny how even die-hard subjectivists would say it is ok to study the specs to inform your choice of cartridge but not so for anything else.
Somewhere in the line of recommenders of certain combo's (who might be die-hard subjectivists), there will always be one that studied the specs but doesn't talk about it.

I've learned that you can use specs and later fine-tune by ear.
My Denon 103R, tuned to 10Hz doesn't sound as good as tuned down to 8Hz.
that's what my ears say. Specs said that 10Hz would be ideal.
I feel specs are a good way to start, but in the end, let your ears decide.

[Bonky]

Somewhere in the line of recommenders of certain combo's (who might be die-hard subjectivists), there will always be one that studied the specs but doesn't talk about it.

I've learned that you can use specs and later fine-tune by ear.
My Denon 103R, tuned to 10Hz doesn't sound as good as tuned down to 8Hz.
that's what my ears say. Specs said that 10Hz would be ideal.
I feel specs are a good way to start, but in the end, let your ears decide.

Hi, how have you tuned your Denon to 10Hz?
Did you add extra mass to the arm, and, if so, did you find it more effective evenly distributed along the arm or just at one end?
Thanks,
Bonky

[OneyedK]

Hi, how have you tuned your Denon to 10Hz?
Did you add extra mass to the arm, and, if so, did you find it more effective evenly distributed along the arm or just at one end?
At first, I tried headshell weights, but in my experience, they do move the resonance frequency, but they also make the peak sharper and higher.
So next step was to use different headshells, right now, I use the AT-LH18 OCC, that's 18g.
Of course, I made my counterweight heavier to fit the extra mass.

With the Technics arm, distributing mass along the arm is very difficult and rather ineffective. So, until I switch to a Jelco, the mass distributed by the headshell is fine for me.

[Bonky]

Thanks; understood.

Regards,
R.