Tonearm mount to the plinth vs arm board vs rotating arm board vs isolated tower

You didn’t strike a nerve, pal, you struck out.

@fsonicsmith 
Nothing is wrong with Aluminum; to the contrary, it is a superb material for almost anything mechanical (there is a reason supercars are built from it). It rings because it is very stiff, and that is usually a good thing, but because it is very stiff (and light), it is very easily damped. So if you dampen Aluminum, you get the best of both worlds; stiffness yet well damped composite. Steel or cast iron is a different matter. It is stiff, but weighty and therefore hard to damped, usually not a good material for anything audio (unless you are building a bell).  

That has been my experience as well sciencecop. FWIW Brass seems to dampen aluminum very effectively in combination with soundcoat material (1/16" thick sheets).  

05-12-2020 1:23pm

In the case of the first you have a subjective means to winnowing out how a separate arm pod is a failed concept;

THE ATMASPHERE PRINCIPLE

THE 'FAILED' CONCEPT

Thank you for reminding me of why I dont use rubber belt drive turntables or direct drive turntables - the swirling and lurching from note to note of a platter driven by a rubber band vs the grainy grey wash of the direct drive as it interminably tries to calculate the correction speed required on ancient "software" using 1970's electronics, not to forget that a can of Baked Beans probably has more structural integrity than the motor housing on the DD.  And to think you can even hear it with a low res MM. Thanks again for reminding me.