Question regarding setting up / tweaking of SME 3009/S2

Hi,

I have this question regarding setting up my SME 3009 improved (removable headshell version).

When I got my Thorens 126 MkI / SME 3009 some twenty years ago (those were times without the Internet) I was told by some "guru" that SME headshell was not that good and that I should do the following tweak:

[IMGDEAD]http://www.kujucev.com/ar/_SME_tweak.jpg[/IMGDEAD]

I stuffed it with a small amount of some sort of black modelling putty (feels like BluTack), filling all small holes. The cartridge at that time was MM Ortofon VMS30 MkII.

I kind of remember that after this tweak, sound got warmer with slightly deeper bass. After twenty years I'm not really sure about the difference, since I never removed the putty...

Question No 1: Is this tweak valid in your opinion?

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Question No 2 (also related to Q No 1): I allways wondered what this really is for:

[IMGDEAD]http://www.kujucev.com/ar/_SME_Q.jpg[/IMGDEAD]

SME 3009 has this setting for cartridge weight. Why? On some other arms you only have VTF and anti-skating settings.

I used to set this to naked cartridge weight. I always checked the VTF with a small Ortofon Stylus Gauge.

Recently, I started wondering if the cartridge weight setting should also reflect added weight of spacers, screws and this putty? Should I also substract the weight of the finger lift thingy that I removed from the headshell?

The cartridge I'm using now is high output MC - Ortofon MC-1 turbo. It is only a temporay solution, since I'll receive my new Shure V15 V XMR in a few days :)

Thanks,

Aleksandar
 
Hi.
The weights are used for altering the lateral tracking of the tonearm when using different cartridges.
If you were to lift the back of the arm up(just for the sake of this argument),then the arm would have a tendency to "fall" to one side or the other.effectively "leaning" the cartridge.
Proper adjustment of these weights should stop this.

The black substance could be SME seating compound(used to create a good contact between cartridge and arm,especially when using SME plastic bolts/nuts that they supplied with the Series III arms),or it could be Blacktak(bit like Bluetack,but not as sticky and made for hi-fi use in the same way as the SME stuff).

The idea of using it in the headshell is ok,but if you really want to be finicky about it then it is adding a lot of mass to the end of the arm which may not suit it.
Another option is to get hold of an ADC magnesium headshell.I've used them myself to great effect and know that a lot of people virtually swear by them.

The cartridge weight will be unaffected by nuts/screws/fingerlift etc. as your initial setup for downforce will be based on the fact that you should have perfectly balanced the arm on it's pivot,before applying any downforce weighting.The only things they doeffective affect,again,is the mass.

If you would like to know a great deal more than I could ever tell you,then visit;

http://www.theanalogdept.com

http://www.theanalogdept.com/images/spp6_pics/SME/SME3009R/ModelsRtype.pdf

http://homepages.compuserve.de/kistneraudio/txt/Antiskating.txt

These sites are readily available using standard search,so I don't think i'm breaking any rules by posting them.

Best of luck anyway.
mschwilson
 
Hi Aleksander

The guru was right - these flimsy headshells can benefit from extra mass and the 'improved' version is definitely too light for most moving coil cartridges.

The lateral weight is for setting lateral balance. It may not be too important for fixed-bearing arms but with knife edges you definitely want the same force on each side of the bearing. With the earlier 3009 there was a simple procedure for setting this up. You push the back of the arm up and adjust the balance until both sides of the knife edge bearing lift at the same time.
 
The cartridge weight will be unaffected by nuts/screws/fingerlift etc. as your initial setup for downforce will be based on the fact that you should have perfectly balanced the arm on it's pivot,before applying any downforce weighting.The only things they doeffective affect,again,is the mass.

I'm not sure that I understood this...

Is 3009's lateral balance setting "calibrated" to empty standard headshell with its finger lift thingy?

How would the 3009 "know" if the weight (that has to be compesated through lateral balance setting) is coming from heavier cartridge that is used alone, or from some other lighter cartridge with added weight in form of putty, longer screws, extra spacers, etc?

IMO, it would be logical to include the extra weight in lateral balance setting.
4g cartridge + 2g of extras, or 6g cartridge without extras - it should be the same from lateral balance perspective.

Or maybe I'm wrong?

Thanks for the answers,

Aleksandar
 
Hi Aleksandar.

Is 3009's lateral balance setting "calibrated" to empty standard headshell with its finger lift thingy?

No.The lateral balance is set up once all of the variables are in place,cartridge/bolts/fingerlift etc.
The idea being,that all this weight now needs to be balanced on the arms pivot points(knife edge bearings)to negate the lateral "twist" that this extra weight is causing.

If set up and then you add something else(black putty),then the arm will want to "twist" again,so the lateral balance will now need to be adjusted once more,as will the counterweights and tracking force.

The lateral balance adjustment should be carried out when all other criteria are taken care of,barring anti-skate which is the final adjustment(hopefully).

I hope this helps.
Best regards,
Simon.
 
Simon,

Thanks for the answers!

I wasn't clear enough when I said:
"Is 3009's lateral balance setting "calibrated" to empty standard headshell with its finger lift thingy?"

What I meant to ask is, is the arm's setting factory callibrated to standard headshell, so that all the additional weight has to be taken into account, including non-original headshell...

But your answer confirmed that anyway.

Thans again,

Aleksandar

PS does anybody know the weight of an empty SME 3009 S2 headshell?
 
Why the compound in the holes....?

Hello everybody. I think the compound in the holes of the headshell are not only for providing a better "seat" to the top of the cart, but also for added mass. Lot of people are using a heavy headshell (generally Orsonic) which should help to mate the compliance of modern (I mean after 1980) MC designs to the mass of the tone-arm. Remember Series II are really light (6.5 gms approx.), so if you want to use a low compliance moving coil cartridge, you need a little more mass on the tone-arm and the headshell seems to be the place to put it.
Regards
Zoidy