Sub Platter design Mrm the Source.

[tutancarmen]

I've got an early Mrm . The Source , that had an Heavy Platter and Sub platter made of Brass.
In the later Model Mrm So the Sub Platter has been completely redesigned and inner alluminium hub was enlarged in comparison with the earlier model.
I think that the main reason in doing so was to obtain a lighter and well dumped platter .
The wilson benesch turntable had the inner sub platter of the same dimension of the later MRM so.
Are there any other reason to make a larger inner sub platter ? what could be an ideal inner sub platter design ?

[DiveDeepDog]

Having had my hands on The Source platter(Bronze I thought:scratch:) the reason for it's downsizing and weight reduction would be due to costs?

Its the most beautiful piece of engineering I've seen. It seemed out of place on the cheap and cheerful galvanised steel sub-chassis, although it was stable (5 springs) and sounded great.

If you've not seen the instructions, smear some oil between sub platter and outer to aid dampening .

[sq225917]

Not brass, it was more dense, some alloy of similar colour.

There's really only space and mass considerations to a two piece platter. The worlds your oyster, pick a principle and design accordingly. But think about pulley size and accuracy too.

[YNWaN]

I seem to recall The Source turntable used bronze for the platter. I'm not sure what you mean precisely when you write that the inner platter was enlarged. If you are saying the diameter was increased then the primary reason would be to alter the gearing with the motor.

[tutancarmen]

YNAWaN I think you're right , altering gearing with the motor could be a good reason .
You right the platter is Bronze . Someone said that the latest Source is better than the earlier . In my opinion it was a great and overlooked turntable . Indeed even if much stable than a 3 springs design, the five springs are more difficoult to tune at first .
To get the best the tonearm spring and the relative opposite shouldn't tight at all.
In my experience with such heavy platter the springs should't tight at all. It is not engaging as the Linn 12 but much more neat and transparent than the Linn. To be said that I don't Have the Keel subchassis that I think much improved the transparency of the Linn.