Hello. I have been researching resonance and cartridge combinations, and after reading many posts have decided to get a new cartridge + stylus for less than $150. I will plan on getting an AT 120e cartridge using a new AT 440mla stylus (compliance 10cu's), if the resonance with my Technics SL-1300 tonearm is OK. I decide this after reading online (some random posting on another board) that the effective mass for my tonearm is 16.5 grams. Using the common formula, the resonance comes close to 10 Hz--a good number I believe.
If that is indeed the correct mass, I will decide to get that combination of cartridge and stylus. Would this cartridge and tonearm be a good combination? You guys know your stuff, so thanks for any input.

It might still work nevertheless, but be aware that AT like a couple of other Japanese manufacturers doesn't spec the compliance for the usual 10 Hz, but for 100 Hz. The compliance at 10 Hz is quite a bit higher, should be close to 20 µm/mN...

Greetings from Munich!

Manfred / lini

Agreed. The compliance figures at cartridgedb.com are not accurate. Actual compliance usually tends to work out at about 80% of their reported dynamic compliance. But the cart should work fine nonetheless.

That arm mass of 16.5 g is based on the original headshell. If you use the newer headshell you can knock off two grams.

I have an AT PL120 which is nearly identical to the Technics 1200 turntable. I have run the AT120e with 440MLa stylus for quite a few hours and it works fine with that style arm.

The big deal is to get as lite a headshell as possible. Weight/mass at the end of the arm is not where you want it. The silver or black generics off the 'Bay work just fine. They are lite and long enough to easily get the 52mm overhang needed. Also suggest the silk wrapped headshell wires from LPGear as I believe they are lighter than the ones supplied with the shells (still waiting for my jewelers scale [lost in transit] or I'd have the numbers for you).

Agreed. The compliance figures at cartridgedb.com are not accurate. Actual compliance usually tends to work out at about 80% of their reported dynamic compliance. (...)

Uhm, nice that you agree - but, sorry, I don't get your math... Shouldn't that be +80% or 180%? :scratch2:

Greetings from Munich!

Manfred / lini

Again, thanks everyone for the information.


Agreed. The compliance figures at cartridgedb.com are not accurate. Actual compliance usually tends to work out at about 80% of their reported dynamic compliance. But the cart should work fine nonetheless.


Just a note: I got the compliance from several online sources, including cartridgedb.com, and they were all the same.


That arm mass of 16.5 g is based on the original headshell. If you use the newer headshell you can knock off two grams.

I will probably get a new headshell sometime soon, if that is the case.

(...) Just a note: I got the compliance from several online sources, including cartridgedb.com, and they were all the same. (...)

As already mentioned, in this case it's not about consistency of the given numbers per se, it's about consistency of the measurement method/conditions. To give you an analogy: Imagine you found a comparision table on cars with one column being "engine power" in which the numbers were all correct, but nevertheless not directly comparable, as some were horsepower and some were kilowatts...

Greetings from Munich!

Manfred / lini

Oh, and just for the record, compliance isn't the only problematic kind of spec in the realm of hifi - on the contrary, there are lots of specs which are rather worthless without details. Just a few examples:

- frequency response: pretty worthless, if no limits of deviation (e.g. +/- 1 dB) are given, 'cause what one usually wants to know is not the frequency range in which there's any response at all, but in which the response is more or less flat...

- efficiency/sensitivity (e.g. of loudspeakers and headphones): often mixed up, so one needs to heed the units for comparisions. Efficiency in its strict sense would be sound pressure level per power, measurend at a certain distance - e.g. 85 dB/W (1 m). Whereas sensitivity in its strict sense should be sound pressure level per voltage, also measured at a certain distance - e.g. 80 dB/V (1 m).

- output power (of amplifiers): also rather worthless, if only given in watts without any further details on measurement methods and load impedance...

Want more examples for your further confusion? ;)

Manfred / lini

Yup - synergy is the real world of pieces mated together and sounding as they do irrelevant of the paper specs - and it can be very surprising :)

Just a note: I got the compliance from several online sources, including cartridgedb.com, and they were all the same.

First of all, they are likely copied from each other. Second, I should clarify. Those numbers are accurate as reported, but are meaningless for this purpose. They are not correctly applied to determine cartridge/arm matching. For example, if you are going to use the reported dynamic compliance (at 100Hz) for the AT440MLa of 10CU as a guide to compute resonance for arm/cart matching, you might as well just pick a number out of thin air. 10CU is LOW compliance. The 440 is a high compliance cartridge, as are most of the decent MM ellipticals and line contacts. Compliance is inversely proportional to the tracking force. So when you're talking a low 1-1.8g TF, that's high compliance.

And 100 Hz is not anywhere near the low frequencies of concern. what's the compliance at 15 Hz or there abouts? It's not stated and must be interpolated. For a fact the 440 is a high compliance cartridge. It's a flexy flyer if I ever saw one :)

They are not correctly applied to determine cartridge/arm matching. For example, if you are going to use the reported dynamic compliance (at 100Hz) for the AT440MLa of 10CU as a guide to compute resonance for arm/cart matching, you might as well just pick a number out of thin air. 10CU is LOW compliance.

Now I'm lost. I thought some of the resonance charts for arm/cart matching that have been posted here and elsewhere used the cu listed for the cartridge to determine exactly that. If that is false, then how in heck do you figure it?


Compliance is inversely proportional to the tracking force. So when you're talking a low 1-1.8g TF, that's high compliance.

I dont get "Compliance is inversely proportional to the tracking force."

The eff.mass/compliance charts are OK, at least the ones I have seen.
What You must know when using compliance figures is at which frequency they are valid. You can not use figures measured at 100Hz, then You will get too high res. freq.
To know which frequence is used, You can look at recommended TF. The higher the TF the lower the compliance. If the recommended TF is around 1,5 grams, or slightly below, as with many modern carts, the compliance can not be around 10, but more likely 20-25 at 10Hz.
For instance AT95E has a dynamic compliance of 6,5 and a static compliance of 20. The one that should be used is neither of them, but something more close to 20 than to 6,5.
/gusten

The eff.mass/compliance charts are OK, at least the ones I have seen.
What You must know when using compliance figures is at which frequency they are valid. You can not use figures measured at 100Hz, then You will get too high res. freq.
To know which frequence is used, You can look at recommended TF. The higher the TF the lower the compliance. If the recommended TF is around 1,5 grams, or slightly below, as with many modern carts, the compliance can not be around 10, but more likely 20-25 at 10Hz.
For instance AT95E has a dynamic compliance of 6,5 and a static compliance of 20. The one that should be used is neither of them, but something more close to 20 than to 6,5.
/gusten
Exactly. The charts (and formula used to create them) are fine, it's the compliance numbers stated for the carts that are not valid. In fact, the actual compliance at 10Hz is about 80% of the static compliance figures given at 100Hz.

And yes, inversely proportional means that the higher the compliance the lower the tracking force. A stiffer spring (low compliance) requires more force to compress it and conversely a softer spring (high compliance) less force.

Hmm. Well, now it sounds like a guess, and, if you dont know if the specs given by the manufacturer are measured at 100Hz or whatever, then trying to determine an arm/cart match seems futile. Example of Dynavector 20X (H/L):

Type: High/Low output moving coil cartridge with flux damper and softened magnetism
Output Voltage: 2.8mV / 0.3mV (at 1KHz, 5cm/sec.)
Channel Separation: 25 dB (at 1KHz)
Channel balance: 1.0 dB (at 1KHz)
Frequency response: 20 - 20,000Hz (± 2dB)
Compliance: 12 x 10-6 cm/dyn
Tracking force: 1.8 - 2.2grams
DC resistance: 150 ohms / 5 ohms
Recommended load resistance: > 1Kohms / > 30 ohms
Cantilever: 6mm length, hard aluminium pipe
Stylus: Micro-Ridge
Weight: 8.6 grams


All I see is "Compliance: 12 x 10-6 cm/dyn". Other vendors will advertise it as a "12 cu" compliance, and, will not state how or where it was measured. So what in blazes is the purpose of the spec if it needs to also state at what Hz it was measured at?

Hmm. Well, now it sounds like a guess, and, if you dont know if the specs given by the manufacturer are measured at 100Hz or whatever, then trying to determine an arm/cart match seems futile. Example of Dynavector 20X (H/L):

Type: High/Low output moving coil cartridge with flux damper and softened magnetism
Output Voltage: 2.8mV / 0.3mV (at 1KHz, 5cm/sec.)
Channel Separation: 25 dB (at 1KHz)
Channel balance: 1.0 dB (at 1KHz)
Frequency response: 20 - 20,000Hz (± 2dB)
Compliance: 12 x 10-6 cm/dyn
Tracking force: 1.8 - 2.2grams
DC resistance: 150 ohms / 5 ohms
Recommended load resistance: > 1Kohms / > 30 ohms
Cantilever: 6mm length, hard aluminium pipe
Stylus: Micro-Ridge
Weight: 8.6 grams


All I see is "Compliance: 12 x 10-6 cm/dyn". Other vendors will advertise it as a "12 cu" compliance, and, will not state how or where it was measured. So what in blazes is the purpose of the spec if it needs to also state at what Hz it was measured at?

The need for compliance figures are really only when calculating resonance frequency. It is good if there are in fact some that further can be used. If they are stated at 10Hz, 100Hz or it´s a static value one has to figure out.
The figures that should be used are the ones at 10Hz, it´s worthless to use values at a frequency where there will be no resonance.
/gusten

The need for compliance figures are really only when calculating resonance frequency. It is good if there are in fact some that further can be used. If they are stated at 10Hz, 100Hz or it´s a static value one has to figure out.
The figures that should be used are the ones at 10Hz, it´s worthless to use values at a frequency where there will be no resonance.
/gusten

OK. I understand that, and since in the example for Dynavector it doesn't say if it's 10Hz or 100Hz...So for "calculating resonance frequency", in the example of the Dynavector I posted, what is the compliance used?

OK. I understand that, and since in the example for Dynavector it doesn't say if it's 10Hz or 100Hz...So for "calculating resonance frequency", in the example of the Dynavector I posted, what is the compliance used?

Not knowing this cart at all I still would say that the compliance is stated at 10Hz. If I was going to buy one I may want to be 100% sure, so I would also in that case ask Dynavector.
If I already owned one it would be good enogh just to look at the compliance when playing.
/gusten

If I already owned one it would be good enogh just to look at the compliance when playing.
/gusten

OK I'll bite. How exactly does one do that?

jfine: You can be pretty sure that the compliance spec for your Dynavector is for 10 Hz. Not only as that would be typical for an MC in that class and because it fits better to the tracking force spec - it would also not really make much sense to build such a comparatively heavy cartridge with much higher compliance, as it then would only be good for very light tonearms.

Greetings from Munich!

Manfred / lini

Yes, as lini suggested, you look at the tracking force. When you see 1.8-2.2g then 12 CU makes sense.

BTW, you've probably figured out that CU = compliance units = 10-6 cm/dyn. CU is easier to type.

OK I'll bite. How exactly does one do that?

He may mean just look at the movement of the stylus and see how bouncy it is. But if you know the mass of your arm, you can use a test record to determine the resonant frequency and then calculate the compliance of the cartridge. If you wanted to try this, the test record to look for would be Shure Era IV.

OK I'll bite. How exactly does one do that?

In this case it´s just to see if the cart is low compliance, then the figures stated is for 10Hz, or if the cart is high compliance (not likely), then the figures is for 100Hz.
/gusten

jfine:
For the sonic result it´s very important to have the resonance freq. at a freq. where a resonance most likely will not happen.
The figures for good resonance freq. often mentioned are 8-12Hz. That does not mean that 8Hz is as good as 12Hz in this matter. A resonance will more often be initiated at 8 than at 12Hz. For instance will playing warped records be more easy if we are above 10Hz.
If we look at the calculations for res. freq. one interesting thing is that the eff.mass and the compliance are equally important. That means that reducing 2grams from the headshell, for the purpose of raising res. freq., is the same thing as having another cart with a compliance (10Hz) that is 2mym/mN lower.(To go from 25 to 23) That indicates how important right figures from the manufacterers really is.
/gusten

A few days ago my new jewelers scale arrived so I measured the weight of some headshells with supplied wires. The lightest cast shell I have is an AT9 that measures in at 8.9 grams. The lightest stamped shell I have is a generic silver one from eBay that measures in at 6.9 grams. You can get the weight down and that will allow some tuning to the resonant frequencies :)