Cartridge compliance confusion for the 3009 S2 (None improved)

[The Black Adder]

Hi all.

I've been trying some different flavors of carts in the 3009 none improved tone arm but I'm getting all confuzeled with how manufacture compliance's differ.

I think I might be working this out wrong or just missed something along the way. Can someone please shed any light on these values?

O.K. to start the 3009 none improved arm weight is 12.5g and I've been trying to find a nicely matched cart for this.

I'm sure it's understood that the 3009's spiritual cart is the Shure V15 Type 3, the specs of this cart are:-

Shure V15 Type 3 - 22.5 x 10 with a mass of 6.3g

So should I look for something within that range of spec?

The other carts I'm looking at and using are:

Ortofon 540 MKII - 25 x 10 with a mass of 5g - (TonyL uses this on his set up)
Ortofon M20FL Super - 20 x 10 with a mass of 5g - (currently in system)
Ortofon M20E Super - 40 x 10 with a mass of 5g - (a swap with the M20FL stylus)
Ortofon MC1 Turbo - 13 x 10 with a mass of 4.1 - (recommended by Schopper for my set up)
Goldring G800 - 20 x 10 with a mass of 7.5g - (currently in system but has updated cantilever)

Which one of these would you say suits my arm using the original perforated head shell which I think is 7g

Some help here to understand the compliance and headshell combo would be appreciated as there is quite a difference between each cart.

Thanks

Joe

[DSJR]

PLEASE guv'nor, don't get all het up by this.....

For high compliance cartridges, the SME shell with either a strip of card table baize or better, the black-tac SME supplied at one time, will be fine. Use aluminium screws and nuts with these as the plastic bodies won't take over-tightening.

Another good universal headshell is the Techie style one, available from various sources on fleabay. Rigid and really good with replacement wires IMO, it'll work with most things I find, except the most fussy of MC types.

At another step up in cost and before the mad ones, the Sumiko shell offers a heck of a lot for under £40 still and it's solid enough for Denon 103's and so on.

As for SME counterweights, the ideal is to get this as close to the pivot as possible. My fixed head 'Improved' one will barely balance a V15 III with stainless steel bolts and SME black-tac and once I get to use it, I'll get the weight for the detachable shell version, which on prior experience works a treat here.

[Oldpinkman]

If you are concerned about the compliance / effective mass resonance then the M20E is the obvious "wrong un"

I am assuming the 12.5g "weight" you quote is the effective mass including the headshell. Effective mass is NOT the same as the mass (ie you can't just put it on the scales). Mass furthest from the pivot is more significant than mass close to the pivot. You won't go miles wrong in most cases though if you treat the mass (weight) of the headshell and the cartridge as pure "effective mass"

So the effective mass of your arm with the standard headshell is 12.5gm. If you change for a 9g headshell it would be (near enough) 14g. Both are conventionally considered "medium" effective mass. To that you add the cartridge mass

So your V15 example in the standard headshell would be 18.8g (19 for cash!) The compliance in cu is 22.5 (usually at 10Hz but be careful - Japanese cartridges are often spec'd at 100Hz, so need to be roughly doubled)

You are looking for a resonant frequency ideally in the 10-14Hz range, but certainly above 8 and below 20.

The frequency is calculated by 159/ SQR(M*C) where M = total effective mass, and C= compliance in cu

Giving 22.5*19 = 428. SQR 428 = 21
159/21 = 7.6 is a bit low really but I think it is bailed out by having a damper brush

By contrast your M20E is 40*17.5 = 700 sqr = 26. 159/26 = 6.1 - seriously too low

The ideal is the MC1

M= 12.5+4.1= 16.5. M*C= 16.5*13=215. SQR 215 = 14.6 F= 159/14.6 = 10.9 - perfect! But most other than the M20E will probably be OK

E&OE!

:)

[kininigin]

the frequency is calculated by 159/ sqr(m*c) where m = total effective mass, and c= compliance in cu

giving 22.5*19 = 428. Sqr 428 = 21
159/21 = 7.6 is a bit low really but i think it is bailed out by having a damper brush

by contrast your m20e is 40*17.5 = 700 sqr = 26. 159/26 = 6.1 - seriously too low

the ideal is the mc1

m= 12.5+4.1= 16.5. M*c= 16.5*13=215. Sqr 215 = 14.6 f= 159/14.6 = 10.9 - perfect! But most other than the m20e will probably be ok

e&oe!

:)

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAHHHHHHHHHHHH HHHHHHHHHHHHHHH!!!!!!!!

My head hurts :D

[The Black Adder]

Thanks Dave. I'm just trying to get around the maths to be honest... I thought I had it licked but it seems not.

Richard, that's great, thanks.

Just a couple of things... lol

"SQR 215 = 14.6 F= 159/14.6 = 10.9" - What is the 14.6 and the F value, is that Frequency?

Cheers

Brain hurt, it's too late and I'm going to bed. lol :)

[Oldpinkman]

Joe
Sorry - I was replying on my galaxy and couldn't draw maths functions. F is the frequency. To calculate it add the effective mass of the arm headshell and cartridge (and fixing hardware) to give you M.
Treat cartridge and headshell actual mass (what they weigh on the scales) as effective mass as a rough and ready.
Multiply M by C. C is the compliance in "cu" hopefully quoted at 10hz but not all manufacturers state.
Find the square root of M×C.
Divide 159 by the square root of M×C. That is the resonant frequency of the system - near enough for jazz.

Its actually quite easy maths - if I had you here with a pen paper and calculator you'd get it in no time. If you pm me an email I could send you a simple excel spreadsheet. But its dead easy really.

I am near certain the 12.5g mass you quoted is the combined mass of the arm and original headshell.

And if mr "I don't go on forums" khoubesserian is reading this, yes I know that is dynamic compkiance at a frequency, that effective mass can be different in the vertical and horizontal planes, that it is the effective mass at tge effective length, and don't talk to me about fulcrums before breakfast! It's close enough for jazz.

[Oldpinkman]

Sorry joe
Got carried away
14.6 is the square root of the effective mass (M) multiplied by the dynamic compliance (C)
F the frequency is 159 divided by 14.6


Why 159? Don't ask - it involves pi :D

[Oldpinkman]

Regarding daves headshell suggestions, most if them appear to add mass and that will be unsuitable for high compliance cartridges. Yor problem is that the rest of the arm isn't particularly suited to low compliance (typical mc)
Not sure of your budget but a 1022 should work ok and is not half bad. (Vertical compliance is key)

[NRG]

Good grief. Life is too short ;) http://www.google.co.uk/search?client=safari&rls=en&q=cartridge+db&ie=UTF-8&oe=UTF-8&gws_rd=cr&ei=TNFLUpfjIoia0AX20YCQDQ Select the Cartridge DB (can't link directly)

Find your cartridge and click on the button in the Dynamic Compliance box. :D

[Oldpinkman]

Good grief. Life is too short ;) http://www.google.co.uk/search?client=safari&rls=en&q=cartridge+db&ie=UTF-8&oe=UTF-8&gws_rd=cr&ei=TNFLUpfjIoia0AX20YCQDQ Select the Cartridge DB (can't link directly)

Find your cartridge and click on the button in the Dynamic Compliance box. :D

Handy - bookmarked for future reference :)

Also, in my paranoia about Arthur looking over my shoulder, it occurs that this advice could be confused. A cartridge "match" based on resonant frequency doesn't amount to a recommendation that it will sound good. If the cartridge sounds naff, sticking it in an arm which puts the resonance at 13Hz won't make it sound any less naff. you have to listen to a cartridge and see if you like how it sounds.

The resonance issue is an "unsuitablity" check. If the system resonance is too high - above 16Hz is usually the cut-off, it will directly affect the sound produced "interfere with the audio frequencies". If it's too low, it risks disturbance by record warps and the like. In the Goldilocks zone - I feel completely safe in 10 to 14 Hz but most go down to 8 Hz - then you avoid those 2 problems. But it could still sound rubbish. So pick a cartridge you like the sound of, and make sure it is "in the zone" for your arm, or get an arm its in the zone for.

Phew - the old git has really spooked me with that Technics v Vestax post. :rolleyes:

[Oldpinkman]

Good grief. Life is too short ;) http://www.google.co.uk/search?client=safari&rls=en&q=cartridge+db&ie=UTF-8&oe=UTF-8&gws_rd=cr&ei=TNFLUpfjIoia0AX20YCQDQ Select the Cartridge DB (can't link directly)

Find your cartridge and click on the button in the Dynamic Compliance box. :D

Just searched the 1042 using that, and it found it but doesn't quote the compliances. And you still need to do the sums to work out your system resonance. Or did I miss something?

[NRG]

Click on the Resonance Evaluator link, put in your arm mass. You know the approx. weight of the cart and its compliance so you can quickly scan the chart for the approx. resonance. Or just use the 1055 compliance in the first page...

[The Black Adder]

Thanks for clarifying that Richard. I think I just forgot how to work it out.

Many thanks guys for the link etc.. I like to know how to work it out that's all. I'm that kind of brain. lol.. although my brain seems to be fried at the moment.

[Barry]

Don't any of you look at "The Knowledge"? There is a perfectly good article that explains arm-cartridge resonance: http://theartofsound.net/forum/showthread.php?22373-Arm-cartridge-resonance.

Whilst we are still finding a way to include an on-line catculator for AoS, reference is given to a chart that allows you to find the resonant frequency given the arm and cartridge properties, as well as the formula quoted elsewhere in this thread.