Here's the way I try to think of the difference between an idler and a DD as regards plinth design: In the idler, the motor and idler itself are "external" sources of noise and vibration, whereas the rotation of the platter and the bearing can be just as inherently silent as that of a belt-drive table. A high mass plinth can drain away the motor/idler noise before it reaches the platter/bearing. That makes sense to me. On the other hand, in a DD table, the motor is a priori and inseparably associated with the bearing/platter. In a way, it's a closed system. So it is not obvious to me how a high mass plinth per se can efficiently interdict the transfer of noise to the platter from the motor. That's why I admire the thinking that has gone into Albert's plinth; there is an attempt to drain spurious noise into a heavy iron block via a threaded rod that contacts the base of the motor/bearing assembly. So instead of going upward into the platter, the spurious motor and bearing vibrational energy has a low impedance path downward into the iron block. In theory, it makes a lot of sense and similar strategies could be adapted to other DD tables. The high mass plinth may just be icing on the cake, to dampen chassis vibration and provide a solid base for the total structure. (I guess other plinth-makers have used a similar strategy to Albert's; I am not assigning a patent on the idea.)
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- 17 posts total
- 17 posts total