Rock music will soar with direct drive.@mikelavigne Just FWIW, its not possible to build any sort of audio playback that favors a certain musical genre.
I must confess that I don’t really get this, as I don’t see how a mat can simultaneously be an effective and non-reflective absorber of energy and have the same hardness as the vinyl record.If you are transferring vibration, to absorb that vibration at all frequencies the material to which the vibration is moving to has to be the same hardness as that which imparts it. In this way all the molecules move together. But at the same time, there is no material whatsoever that can receive vibration and not absorb some of it. This is easy enough to google, here's an example:
https://www.quora.com/What-is-best-known-material-that-can-transmit-vibrations-without-absorbing-vib...
So the trick to to create a platter pad that at its surface has the same durometer as vinyl, but internally is better prepared to absorb vibration- so this does not mean that the material is amorphous. Dissimilar materials are well-known to absorb vibration from each other (we use this principle to damp our preamp chassis, but of course any extensional damping compound is doing exactly that) so a platter pad composed in this manner would be quite effective.
At the risk of disagreeing with those who know more,If the motor has good bearings and the design of the 'table is correct, any vibration the motor has is quite minimal. To give you an idea of this, the motor in my mastering lathe makes 1/8hp but because the shafts which run between the motor and transmission have isomeric isolation, vibration from the motor is not picked up during the mastering process. The same thing can be done in playback; the motor for the Empire machines is isomerically mounted and simply makes no noise in playback; on top of that the Pabst motor used is notoriously silent despite its amazing amount of torque. Tom simply made too broad a generalization!
- agree with the late legend Tom Fletcher, who thought that powerful motors generated powerful vibration hence audible distortion;
- agree with the air bearing crowd who think that all conventional bearings cause vibration in the platter, which is audible;
Air bearings of any sort provide a different problem! For a turntable to work properly **without coloration**, there must be no play between the platter and the plinth and the plinth must be completely dead while rigidly coupled to the base of the arm; in this way the arm and surface of the platter are only able to vibrate in exactly the same plane. The pickup is thus unable to interpret vibration as a coloration or noise of any sort. To this end of course there can be no play in the bearings of the arm and the arm tube must not be able to 'talk back' (resonant) to any vibration being picked up by the stylus; in essence the cartridge is held rigidly in locus. Air bearings of course violate this basic engineering principle. To understand this better, think about the steering of a car because its exactly the same mechanical engineering principle. The wheel has to stay on the road but has to be guided by the driver. If there is play in this scheme, the car will be dangerous to drive and quite scary. Imagine installing an air bearing in the linkage of the steering of a car!