Skeletal vs Plinth style turntables


I am pondering a new plinth design and am considering the virtues of making a skeletal or closed plinth design. The motor unit is direct drive. I know that as a direct drive it inherently has very low vibration as opposed to an idler deck (please do not outcry Garrard and Lenco onwners coz I have one of those too) but simple facts are facts belt drive motors spin at 250rpm, Lencos around 1500 rpm, DD 33 or 45 rpm. That being the case that must surely be a factor in this issue. What are your thoughts. BTW I like closed designs as they prevent the gathering of dust.
parrotbee

Showing 1 response by basephysics

Halcro and Dover are correct although both muddy the waters slightly.
Halcro, by explaining the principles of structural forces necessary to move a sufficiently large armpod and Dover by mentioning the speed-correction circuitry of a DD turntable.
Neither point is relative to the Timeline and a moving armpod.
A moving armpod will be displayed by the Timeline on a belt-drive turntable and idler both without servo control.

The mistake being made is concluding that the Timeline is measuring rotational speed.
It is not.
The rotational speed is pre-dialled into its algorithm so that the flashing strobe merely confirms any deviations.
The Timeline device actually measures 'movement' to a microscopic degree. That is why it is able to visually display the effects of stylus drag as 'movement'.
As Dover points out, in a closed-loop system, any movement of the dependent particles in relation to another will be displayed by a device designed to detect movement.