Well, I think the larger then rational mass of “silent” TT platter eliminates all other moments. If you have a 150 lead-like platter then would it be direct drive, belt drive, or pinch roller would be absolutely irrelevant. The moment of inertia of this thing would be mammoth and you can apply torque by impulses once a second – the platter will not have reflected it on sound. The ultimate tonearm for the “ultimate turntable” is a whole another subject…

Still, if I go for ultimate turntable concept then in my book where less is more it would be a large mass TT with air or magnetic (perhaps electromagnetic) suspension. It is interesting that in the subject of “big turntables” the turntables have some kind of mysterious high values; this it is very little in analog come from a TT. There are expensive turntables out there with price tag of $30K, $50K, $80K…. What an idiocy! A function of TT is to spinning a disc – nothing else! Why should it be so expensive of complex of even simple and cheap $100 turntables already produce speed stability that is order of magnitude more stable that it is imaginable to hear. In fact the most horrible problem with speed stability I ever experiences in my live was from $100K Continuums Turnable… so where is the common sense?

Romy the Cat wrote:

Why should it be so expensive of complex of even simple and cheap $100 turntables already produce speed stability that is order of magnitude more stable that it is imaginable to hear. Teh caT

Very cool question. Without having any rational justification to make any educated guess I would pull idea out of my ass – just because the idea make sense to me.

If I make a massive palter I would go for very tall vertical shaft to minimize the platter’s latitude bearing. As the example might be taken the EMT 927 with a long tail below – I love the idea. However the longer shaft, the more shaft surface the more tension in the shaft - so it should be balanced somehow.  No ball bearing would care >150poinf, unless you want to fix it each two years. So I would use some kind of other methods – air or magnetic. But there is a ketch in it. I still believe that the platter should not be decoupled from the base – I have written about it in the beginning of the thread. A platter should be grounded, not electrically but mechanically and it should have path of mechanically ground. So, if I go for an ultimate solution then I would suspend the platter with air for insane in order the air to care 95% of the platter mass. Then I would have the ball bearing that would care the reminding 5-10 pounds. Sure when the platter is not spinning I should be not lower to the flimsy bottom bearing but somehow maintained in a lifted position.

enjoy_the_music wrote:

Making a vacuum hold down is quite simple, but would it be easier to use a device like the old Audio Technica AT-666? I guess the material used in the latter is not the ultimate. You don't need a great amount of vacuum to hold the record down.

Actually you are incorrect. To make vacuum hold down properly is quite complex. The ay how Audio Technica and Sota did it was simple but it is why it reportedly did not work well. (I used Sota a few times). Micro did it extremely good with real-time sucking. The benefits are arguable though – there are some pluses and some minuses. I feel that the idea of negative curving is much more interning then the vacuum hold down, still even the negative curving have own pain in ass disadvantages.

N-set wrote:

let me point out that the force injected by the needle moving through a groove can apparently be quite substantial (loud passages etc) dynamically slowing down the plate.

Only with flimsy platters perhaps. With heavy enough platter and with a platter with right damping it should not be the case.

guy sergeant wrote:

There was a Japanese company called Melco who did some experimentation with platter mass back in the 70's.  I seem to recall that they felt 30Kg was where it stopped making a difference.

Melco was in bad with Micro and I think Micro came from Melco. Japanese has another company with a ridicules name: it was called “American Sound“, they made TTs even heavier then Micro 8000

guy sergeant wrote:

The greek ACA president with his flywheel assistance feels its alot more. http://www.aca.gr/paper37.htm

Wey good artailsy, I have seen it before but never was able to read it carefully. I hate to read from computer screen and it a site has no printing options then I tend do not read it. From what I was able to glance I might say that if his platter takes 30-60 minutes to stabilize then his design is bogus. Putting, record in, touching the platter, cleaning the record – it is all affect the pressure to the platter and platter should be able to recover it really fast. I hate to think that I need to hard-clean record and then wait 10 min until the platter get cruse speed.  I think all heavy platters should have step-torque controls.

guy sergeant wrote:

Personally, I feel DD done properly is an adequate and more elegant solution. The fact that it was accurate enough to cut the records we listen to also suggests this to be the case.

I think it is incorrect rational. I am not proposing that DD idea are bad or good I just say that juts because some companies in past make DD cutting lathes then it proves absolutely nothing and should not be a reason for imitation juts “because it was cut on TT lathe”.  It is not to mention that all earlier cutting lathes were belt driver and then, for the sake of economy/space some of them went to DD. BTW, none of the c used heavy platters. I am sure if someone would case to make the cutting lathes today, with contemporary high level of demands and with the same amount of appreciation as it was done 60 years back then the today’s lathes would be much  more capable then the best  Georg Neumann’s lathes…

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N-set wrote:

let me point out that the force injected by the needle moving through a groove can apparently be quite substantial (loud passages etc) dynamically slowing down the plate.

Only with flimsy platters perhaps. With heavy enough platter and with a platter with right damping it should not be the case."