Twl,
You have provided yet another interesting discourse on the importance of the turntable. Keep it coming!
The turntables contribution as a provider of all time-domain information is really a mind twister to be sure, but true. One can make the same argument of the transport mechanism in CD players. Without motion, in either case, there is no music.
The bearing is also important, as you say, and it gets so little attention being buried deep in the plinth. Without robust construction, ample lubrication, and being constructed of high quality parts, the bearing will be unable to help the platter rotate at a constant speed without wobble. Even minor movement can create vibration that is then transmitted from the platter to the cartridge where its passed onto the speakers as noise. And if the turntable and tonearm resonate too much from airborne vibration produced by the speakers, these resonances create a feedback loop making the situation even worse, something I head with the Denon/Koetsu combination I discussed earlier.
>>The better turntables allow the cartridge/tonearm combination to perform at a better level because they are presented with the record information from the groove in a more stable manner, both vertically, horizontally, and in the time domain. Without this proper stability of the record groove, no stylus/cartridge can work at its best, and therefore will perform at less than what was intended.<<
If vibration, wow, flutter, and rumble levels are too high, or if they interfere too much with the proper functioning of the cartridge, no matter how expensive that cartridge might be, the cartridge will not live up to its full potential and may even perform at a lower level than a less expensive transducer on a great table. I experienced this firsthand with the Denon/Koetsu combination. While the sound of that combination was good in relative terms, it could have been easily equaled by a cartridge costing only 1/10th the price, or even less. So my experience does correspond to what you have written above. To hear a truly rock-solid turntable spinning ones favorite vinyl can be awe inspiring: the background is jet-black and silent, every detail is clearly rendered, bass is thunderous and palpable, and there is a prevalent display of upper-octave bloom and air that cannot be equaled by digital.
>>I only point out that the cartridge can only transducer what it reads, and the arm can only hold it properly over the groove, so that the turntable can feed the information to the cartridge effectively The turntable provides the environment for the cartridge to work. If the environment is poor, the cartridge cannot make up for it.<<
I think this statement sums it up nicely.