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Graham Phantom II 12" - dimensions and overhang

Hello guys,

I come from Europe and recently purchased Graham Phantom II tonearm with 12" armwand.I was missing specs for 12" armwand (in manual are specs for 9" and 10"),so I emailed to Bob Graham and asked him for specs for 12" version. The answer was,that 12" version should be adjusted same as SME V 12". Bob sent me document with SME dimensions as well.

So regarding this document specs are Leff 308,8, overhang 13,2, mounting distance ( Pivot-Spindle) 295,6.
To adjust mounting distance is easy using any quality protractor. I used Acoustic Solid.

http://www.acoustic-solid.de/html/schablone.html

So with mounting distance adjusted to 295,6,here comes the thing.
I should set overhang to 13,2 regarding to specs for SME V 12",but simply
elko
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923 posts
 
Hi

I am dealing with similar issues after upgrading our 9" Phantom to 12" Phantom II supreme. We needed the 12" arm wand for the new TTWeights Momentus Duo Drive table we just got in for demo and sale, which has an outboard arm pod.

I am ordering a new Mint LP protractor for the 12" arm and this is the info I got back from Yip atMint LP. The numbers are in mm. and recommend the Mint LP unit highly. The one I had for the 9" version worked extremely well.

"For the 12-inch Phantom tonearm the spec is totally different:
295.6/308.8 Mounting Distance/Effective Length."

Hope that helps.
elko OP
3 posts
 
But that is the thing,that these specs,which Bob sent me,does not work with me.
When I adjust mounting distance to 295,6mm,I simply cant make overhang 13,2mm. 13,2mm overhang is for Baerwald scheme.

I am getting around 16mm and than screw,which is holding cartridge in headshell hits the inner edge of headshell and I cant move cartridge anymore.
It seems to me,that Leff is bigger than 308,8. I made some calculation for Baerwald scheme and what can work with me is this:

Leff 313
Mounting distance 300
Overhang 13
Offset angle 17,37

With these numbers,I will be able to adjust cartridge in headshell correctlly.
albertporter's avatar
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albertporter
4,949 posts
 
Has anyone figured out what's going on with the 12" Graham?

I have one and using the SME 312 mount template the tonearm base angle does not allow the arm to swing all the way to the run out of the LP.

I'm going to check on this again soon but if anyone has more data it would be great.
suteetat
435 posts
 
I just got Graham 12" last month and there is no spec available. The manual is still for 9/10 inch arm only. It only said to look at addendum sheet for 12 inch spec but there is no addendum sheet anywhere in the box that I could find. So far I use only setup tool from Graham which seems to work ok but I am not really overwhelm by the result. I am thinking of trying mint protractor since it seems to really help both JWM 10.5 and Reed 3Q significantly.
sarcher30
596 posts
 
If you use an arc protractor like the Mint LP you will get the correct offset angle. As long as the arc protractor is designed for correct P2S for the arm you're using and you follow the alignment for zenith you will have the ideal offset angle. Just ignore the offset angle on the Graham 12" armwand as it is not correct.

Sean
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