Vintage DD turntables. Are we living dangerously?

Thucan -
it is very simple.The stylus is measuring the groove. To accurately measure the groove the platter and arm board must maintain a constant relationship. They must be rigidly coupled via a close loop system to ensure there is no differential movement between the two. Imagine trying to measure the length of a piece of wood with the 0 point of the tape moving back and forth.

A similar case can be argued for having a rigid closed loop between the motor and platter. Physics tells us that where a platter/arm are not rigidly coupled to the motor drive, then there will be speed instability. Examples are
1) Where people put TT's on air platforms and the motor is on another table
2) The motor is mounted on a chassis and the platter/arm are mounted on a suspended suspended sub chassis.

Totem395,
you`re right. Maybe I was asking too much in general. I am not referring to the theoretical implications. Copernicus should blame me. I thought in the meantime there could be some more experiences from experimenting rather than describing why one belongs to the stand alone camp or related camp, no? Everyone is proposing only THE ONE SOLUTION?

Back to the practical side: I am experimenting with stand alone and related implementations. For my 100M I am just building a very massive stand alone pod and I`d like to find out if it really makes a difference when the pod is related to the Denon or not (in case I am suceeding doing so)?

For the 101 I am attracted by Henry`s pod design. Only my EA-10 will not fit into one of the pods due to its large counter screw.

Another idea is building a massive substructure for the 101, precisely drilling a 40 mm high and 400 x 400 mm massive aluminum bases (like with the MS RX 5000) and incorporate four related arm pillars at all four corners similar to the Micro Seiki`s ones. In the middle of the bases I could carve out a 5 mm deep recess taking up the Victor thus fixing the 101, not moving around from this position.

When done properly by using 30mm steel knobs and original 20mm MS bases I have no problem using cantilevered armboards. In this implementation the pods would be related. I am not decided yet. Any ideas?

thanks Fleib and Dover - very helpful indeed!
what do you think about the two implementation designs I mentioned above?

Thuchan,
Contemplating a DD non-suspended table, I disagree with Dover. In this case mass/weight is used to insure the platter is not a moving target, and the mounting surface for both arm pod and platter is potentially a superior "closed loop" system. You're simply using the mounting surface to close the loop. Using a plinth or subchassis to insure stable arm/platter relationship is convenient but might have greater potential for degradation.

In practice, I think good results are more dependent on implementation with either approach, and I wonder about a cantilevered armboard. Seems like a bad idea.
Regards,

Dear Thuchan, Dover and I are occasionally at odds, whereas I almost always agree with Fleib. However, in this instance, I disagree with Fleib, and I could not have stated the case any better than did Dover in his initial response. Obviously, a rigid relationship between the tonearm pivot and the platter bearing is a sine qua non for a suspended table, but it is also for me a "must" even in the absence of a suspension, and Dover said why. Like Totem said, this subject has been discussed ad nauseam. By now, those who will ever be convinced one way or the other have been convinced, or not.

I do think that a massive arm pod, such as the ones built by Halcro, linked rigidly to a massive cylindrical plinth (rather than standing on its own) would be a great way to go. Best of both worlds, you could say. Or, you could make the shelf part of the system by bolting the arm pod AND the plinth to a suitable shelf material.