Nude Turntable Project

Halcro.
You are using a plinth.
It is the shelf upon which your TT sits via the spikes you are using.
It would also seem logical that different shelf materials, size, shape, support method, spikes, et el would make a difference.

Richardkrebs,
I imagine it’s possible to ‘define’ an object into existence to suit one’s argument….but I’m not sure where it gets you?
To define a ‘plinth’ as a ‘shelf’ allows for a ‘rack’, a ‘platform’ and of course the ‘floor’ to also comply with that definition.
It gives us the situation where audio items like power conditioners and DACs and SUTs and preamps and amps are all on ‘plinths’?
And for those with a REAL turntable ‘plinth’ on a Minus K stand on a shelf on a rack on a floor……..we have a plinth on a plinth on a plinth on a plinth……..?

It would also seem logical that different shelf materials, size, shape, support method, spikes, et el would make a difference.

This would only be “logical” if one could conclusively prove that there was ‘stored energy’ within the shelf or within the object ON the shelf which REACTED to the “materials, size, shape, support method, spikes, et al” in a way that affected the motor, bearing, platter, record, stylus, cartridge and arm in a turntable system for example?
Despite the availability of accelerometers and other devices designed to measure and quantify vibrational energy and its transfer within materials…..I have seen no scientific evidence to support the many statements made by audiophiles on the nature of ‘vibration draining’ in regards to turntables….and any quantification of such?

The vast majority of audio systems are supported on the floor of the listening room albeit on racks or stands of some sort.
The vast majority of those floors are suspended timber frame or suspended concrete slab…..very few are concrete slab-on-ground.
All suspended floors (be they timber, steel or concrete) are under bending stresses of various magnitudes which create low frequency acoustic energy within the structure.
This low frequency energy (often resulting in movement) is transferred to the rack/stand/shelf supporting the equipment and results in higher frequency energy transmission and movement which is passed through to the equipment supported thereon.
With all this low frequency energy swamping the stands, racks and shelves……it is no wonder that differing methods of support and differing materials all have an effect on the transmission and damping characteristics?
But you are mistaken to assume that those who have absolutely no structure-borne feedback will also experience the same phenomena.
My floor is a reinforced concrete slab-on-ground topped with polished granite and is totally bereft of any structure-borne sound.
My turntables sit on a stressed-skin MDF shelf cantilevered from a masonry structural wall supported on that reinforced concrete slab.
The turntables sound identical whether they are sitting directly on the polished granite floor or up on the cantilevered shelf.
I have tested many methods of support for the turntables including an additional independent shelf on top of the cantilevered one….sorbothane feet, Delcrin footers, Stillpoint Ceramic feet, Stillpoint Ultra Minis, ceramic cones, aluminium cones, steel cones, plastic cones, brass spikes, steel spikes and stainless steel spikes. I have placed various materials between cones/spikes and the supporting shelf including metal coins, plastic, cardboard etc……and with all and every variation…..there has been zero change to the sound.
When there are no Structure-Borne feedback problems……there is nothing to affect the turntable adversely (other than Air-Borne feedback…..but that is another can of worms).
In fact a sure way to determine whether your room suffers from Structure-Borne Feedback is to see if changing the spikes, rack, footers etc results in an audible change?

But back to the plinth……I’m sure you have much to contribute to a discussion on a ‘real’ plinth into which a turntable like a DD or Idler may be mounted? :-)

Halcro.

We are both blessed with having music rooms that have concrete floors sitting on mother earth.

My definition of a plinth is likely a little wider than yours. To me it is.. "the structure that maintains accurate dimensional stability between the record surface and the tonearm". I am sure that you will agree that dimensional stability in this area is critical. I have also called this structure a "loop" in an earlier post.

By that definition your very nicely built stainless steel motor support, the shelf(or floor) and the equally nice arm pod are all parts of the plinth.

It would be reasonable to expect a change in the sound, if you were to change the stainless steel support for say a large diameter cardboard tube. Likewise we could expect a change in sound if the arm pod was made from say balsa wood. I suspect that your choice of these materials was based on experience and sound logic.
Since substitution of different materials would likely alter the performance, it can be inferred that your "plinth" does have a sound.

Aigenga,
In the TT101 Service Manual it explicitly states that the bearing needs no service, which would include periodic lubrication. Bill Thalmann also strongly advised against trying to "lubricate" it. You may fairly respond, and I would agree, that Victor probably did not envision a 30-year lifespan for the product. Therefore, at this point in history, some attention to the bearing may be merited. What did you see when you first accessed the bearing? What was the condition of the lubricant, the bearing, the thrust plate? I am just curious; I don't think what you did was necessarily "wrong" in any way. What lubricant did you use when you serviced your bearing? Thanks.

Halcro,
I think what you have now is a "plinth" by my own definition. Many if not most of the best belt-drive turntables are built with solid, heavy bases that do not afford an open deck surrounding the plane subjacent to the platter; I always thought that was a good idea, as is yours. If I had it to do over, I might have fashioned my own slate and wood plinths in a more minimalist way, but I am not about to do it over. By the way, my Lenco most of all benefits from its dense slate plinth. Why re-open the argument?

Lewm, the fluid was brown and had particulates in it. The bearing looked fine, the plate is soft white plastic so was dented by the bearing but otherwise fine. I do not recommend opening the bearing up unless you have detected a problem. I thought I had made that point in my narrative. But it isn't a real issue if you do it right, and it also enabled me to put rubber/steel grommets between the motor and the frame. All for education and hobby-fun.
Gary