A Copernican View of the Turntable System

T-bone, thanks for your helpful comments. if the plastic piece does not link the arm pod with the TT what kind of material will do it? I always use isolation platforms: the TOHO stand is placed on one, the motor on a separate one, the turntable on three isolated feet with platforms and the whole system again on a special Copulare isolation table (platform structure as well as feet).Following JC's suggestion to shield the TT i should build a surrounding shield for allover wave protection around the Continuum. This I can do. What is the best material and how much of the turntable needs to be covered, 100 mm above the highest point (tonearm)?

best & fun only

Thuchan,
This is, as Dgob points out, only theory. However, following that theory, one would say that having armpod and turntable on different isolation platforms would be sub-optimal. One could see this by having the table be absolutely, perfectly stable and putting the arm pod on top of a sponge-y material - the arm-mount/arm bearing is isolated/coupled to a different extent than the table bearing. Any movement anywhere (the ones your isolation platform is supposed to counteract) will lead to distortion because of the mismatch in response of the bearing surfaces. Putting both on separate isolation platforms does not necessarily improve things as trying to match the resonant frequencies of the two isolation platforms in both frequency AND phase is almost impossible (primarily due to differences in platform loading leading to both different frequency and different reaction time to a given impulse). Or so the theory goes...

Thuchan,T_bone is referring to the "cantilever effect". A separate armboard/armpod should be linked to the plinth by means which are as rigid and as stiff as the material of the plinth itself.
Otherwise you would create an "elastic joint" similar to a cantilever.
In the very same sense a separate/free standing arm pod in it's relation to the plinth/turntable is "connected" to the plinth. With inevitable effects on energy transfer and resonance behavior of the "closed circuit" mechanical system (here: stylus/cantilever - tonearm - arm pod - common ground - plinth - bearing - platter - record - stylus/cantilever).
That's what Jcarr meant when he was referring to the "grounding principles in amplifiers".
Cheers,
D.

Dear Thuchan, It is impossible for me to resist the temptation. You can probable also use the shild surrounding to protect yourself from radiation in case of an nuclear war.

'Peace',

Dear T-Bone, Dear Dertonearm. Oh yes theory is a wonderful thing but are there any experiment documentations available which support the "cantilever-theory" as well as the "isolation theory (of different platforms)".

Funnily I made the experience when I put the motor drive and the three legs (feet) of the Continuum on extra platforms the sound is quiter and dynamically better. I would never return to a non isolation concept.

Nandric is right he knows how to handle the issue seriously ... :-)

best & fun only