New 55,000 Euro tonearm

Dear @dover  : First I was refering to the Netherlands new field coil unipivot not the Kuzma and in the other side ruby and  sapphire is the same material with same characteristics and only different color.

 So " touching " you are.

R.

ruby and  sapphire is the same material with same characteristics and only different color.

Sure - if you use Wikipaedia for your knowledge base.

I have seen several moving coil cartridges over the years with cantilevers made from sapphire tube.

I have never seen a cantilever with a ruby tube, only solid ruby.

Perhaps you need to look beyond wikipaedia for your knowledge base.

@larryi 

The actual bearing housing around the tube ( that rotates for horizontal motion ) is no bigger than my old Zeta tonearm which has a similar layout. The Zeta effective mass is only 14g - so as you point out the apparent bulkiness around the pivot point gives no indication of the effective mass.

However the lack of specifications on either their website or reviews is an issue for me. Two of my favourite cartridges are medium compliance and will not work optimally in a high mass arm. I would not buy the arm unless they can tell me the effective mass.

@dover, that is quite a caustic response. You might want to tone it down a little.  

@larryi , you are absolutely correct. Carbon fiber can be very misleading and tubes that look massive may not be massive at all. On the other hand thin walls resonate more so they have to be thick enough to prevent resonance. Metal is a lot easier to eyeball and the horizontal bearing carrier is pretty massive and still effects the inertia of the arm to a significant degree. I think if you compare it to say a Schroder CB you will not have any difficulty telling which arm has a lower effective mass and less inertia. Judging buy the cartridges I see used in the SAT arm it is at the higher end of the medium mass group. I agree that not publishing the effective mass is a problem.

The SAT arm tube itself is a similar mass as a conventional arm tube from aluminium. 

Basically carbon fibre is lighter than aluminium.

SAT have used this attribute by using a larger and thicker cf arm tube that significantly reduces unwanted resonances compared to an aluminium arm tube of the same mass. 

This from their mouth.

However still doesn't tell us the effective mass.