Why do turntables sound different?

So far scientists among us don’t participate, and I suspect I know why - they have no idea.
If all seemingly great turntables sound different, than perhaps none of them sounds quite right. Each distorts and colors the sound in its own way.
I would also assume that mechanically matching table and arm could be important. And cartridge is the third element. Maybe all three should be matched ?

Bearing friction..
Anyone experimented with different oil? I didn't. I just use Nottingham's oil that they make for their tables. The sound is on a warmer slightly darker side and there is nothing slow to it. Belt is like new, doesn't feel or look wrong, only about 600 hours on it.

Also, some tables apparently sound 'bigger' than others. Some sound 'bigger but slower', others 'bigger and not slower'. This observation does not come from my experience, I read about it.
I would say that my Spacedeck definitely does not sound 'small' and it is not 'slow' at all. Does it have to do with the platter mass and bearing?

Now, how exactly do the table designers calculate the mass of the platter ? Or they don't but just listen ?

I am not looking at it from the right/wrong perspective. I simply wanted to initiate a serious discussion. If the mass of the platter is not determined by calculations and listening than it appears to be BS approach. Of course, it's all connected to bearing and drive. That's what I am asking - how the hell is all that bloody interconnected stuff determined? There are only a few elements but I suspect that mathematics and physics behind it should be quite advanced.
And why would Library of Congress and other establishments use mostly Simon Yorke turntables, that do not seem to be especially popular among audiophiles? I didn't hear them use Technics or Walker or that Japanese shining iron you can put four arms on.

Right. This is a very scientific approach - let the others do the job and steal the design. Some would argue, though, that the one closest to tape sound would be the one to copy. Continuum, I don't know, I heard that that's Technics not Walker.

That's what I said - no turntable sounds right, even worse by definition they cannot.

Ralph, would you name those turntables you mentioned that were competent and sounded similar ?
I know, I know, you don't agree aloud that vinyl is inferior to tape medium. Theoretically, maybe not but in reality..

There was a thread years ago about recordings from vinyl to half track high-end deck sounding in some respect better than the record. There were a lot of arguments from both sides. I think, tape has more fluidity and continuity, it also sounds bigger with more powerful propulsion. Few audiophiles will openly admit that their super set-ups don't have the best source existing.
I don't have any direct to disc records, but to compare you need to have both tape and record of the same recording. Someone must've done it.
So, all great turntables should sound similar, not the same - that's impossible - but very similar. Just as everything else, perhaps, except speakers ?

racedoc, there will be a significant difference if you leave this thread.

You guys run and sell your Comtinuums, Walkers, TechDases, Kronoses etc. real quick. They are not as good as Technics. And don’t argue, just do while you can still get a good price. Yeah, Rockport too.
I am not talking about 100th generation copy of the master on junk tape. There are much more advantages than soundstage. But it should be top deck in top condition.

If direct drive was obviously the best design approach not many turntable makers would stubbornly continue with the belt drive. Clearly, the situation is much more complex.
Ralph, though you express your own opinion, I think that you misinform some people. You did say that there were many tables that you had not heard. Why would you choose the Technics before auditioning all of the top tables? And tonearms. And cartridges.
I don't have an expertise to voice my opinion and I would certainly not rush when choosing one or another.
Intuitively, that's what I would expect from great belt drive design - quietness and sophistication. I don't need it for jazzrock but I do for the rest I care to listen to.

As I said, according to Ralph everyone with good hearing and sense should go after the Technics and Triplanar arm. And don't forget about Atma-Sphere amps and Classic Audio speakers. Everything should be wired with Mogami cables, of course. That's the current state of the art. Yeah, that's how you lose competition not win.

Oh no, I don't have Studer, that's my future project, but I am familiar with good tape sound. And I certainly would not get any high-end table without comparing it to the tape. As for proper alignment and calibration, I would leave it to professionals, there are still people who know how to do it. It is also how I would choose speakers - with Studer or Ampex as a source. And if I was a crazy audiophile millionaires I would also move along three sets of electronics - solid state, hybrid and tube to audition speakers. Let's say, Gryphon for solid state, Ypsilon for hybrid and Lamm for tube. 
Some would say why such an effort, just get Continuum and that's it. They might be right but they might be wrong too. So, speakers frst, 'wire with gain' second, turntable/arm/cartridge/phono last.
nkonor, why are you so sure about that Technics ? Do you already use Technics and want to upgrade? It's expensive stuff.

Yet, there are those who gave up their Walkers and other high end tables and use highly modified Technics SP-10 MK III while claiming this set-up's with various arms and cartridges superiority. I would be happy to compare if I could. Most likely outcome is that it would be different with the advantages and disadvantages of either, and also a matter of taste and the synergy of the entire chain. At the highest level I believe you have to match everything, including turntable to speakers. The system should work in complete oneness. This would take enormous effort, but that's the only way. Science is science but art goes beyond it.

We are not really closer to answering the original question. In essense, the only kind of answer we have so far is they just do sound different. Or, they just color the sound differently and that's why they sound different. The exact science behind it let alone art remain elusive.

To defend Ralph against myself, though I only attack him when he is advertising, he is not alone who thinks that modified Technics SP10-MK III with the right arm, cartridge and phono comes very close to the tape sound. I just wonder if top belt drive tables were involved in those comparizons. I think, not sure, that when Fremer was evaluating the Continuum Caliburn he actually said exactly that - closest to tape, and so he got it for himself.
It's easy to choose an open reel deck - just get Studer A80 or 810 or Ampex, and if you cannot any of those - Otari. But with turntables, considering that there are many, it's not easy even if you can audition them. But yes, I would actually compare any table with my deck. In other words, even if you are not going to use the deck, you need it to choose a turntable ! And possibly speakers too. In fact, anything. I don't think many do it this way but maybe more than I would expect.

I would also think that the belt in the belt drive design should be very important. It's like a cable, in a manner of speaking, that connects two components. 
I can even imagine that at this level my preference might depend on a particular music and record, so I would take both the Continuum and modified Technics, no need to choose, really.

Problem is always those who buy things. If it's not good enough - don't buy it. It's not water or food, you know.
But, some manufacturers are very good, so it's not all bad.