Tables That Feature Bearing Friction

There are some good ideas:

BUT

super high quality motor

- the Designer has to know this part
- he has to know how to use it
- he knows, it makes his product more expensive

excellent power-supply

- see above

really heavy platter

- the Designer has to know: this alone is not enough
- he has to know how to use it
- he knows, it makes his product more expensive

superb bearing

- too expensive

superb drive counterpoint

- well, you know now: expensive

What is the most hated word today?
I think: expensive
The customer would probably pay the price, but he pays it also, when a "Test review" is great (whatever this means)
or when his wife says "Great, I like it"
Most don't need more.
Or?
A real audiophile lives in pain or is Single :)

Dertonarm, You have written that there should be no force on the bearing in the horizontal plane, and elsewhere you have written that use of more than a single motor is a no-no. (I agree in both cases.) But how would you achieve the former goal in view of the latter principle?

Yep, expensive is the hated word for the day. Expensive applies to both commercial and one off, all out assaults. It's just that the threshold for a one off can be much higher. Maybe a solid gold platter would sound really good...

For me expensive mostly relates to time. There are a lot of ideas that have merit. But it is not possible to experiment with all of them. I am sure that I have discarded some good ideas because I didn't have enough time. Part of the art of design is guessing the most profitable ideas to explore. Nobody gets them all right, but one of the important skills in this endeavor is the intuition to get it right more often than not.

Fascinating stuff . . . great thread (pun intended).

I will admit that I'm having a conceptual problem with the whole "controlled slippage" approach to filtering the motor vibrations from the platter. I can see how it would work brilliantly if all the conditions were carefully balanced . . . it just seems really inconsistent in terms of day-to-day usage, and likely to require very frequent tune-ups at least in terms the thread tension. But I will admit that I am comparatively ignorant of the real-world characteristics of these actual materials in this application.

Just a couple thoughts on the drive-system subject - first, how much data is available on the characteristics of the rotational vibration produced by the motors themselves? It seems to me that the relative strength and spectrum of this energy would be of paramount importance to determining the amount of slippage, the tensile flexibility of the belt or thread, and the necessary mass of the platter (and inertial flywheel device). Second, there is actually one more slippage mechanism -- that between the rotating magnetic force vector produced by the motor's stator, and the speed of the armature. It would seem that it's the interaction of these two time constants (or three if there's an inertial flywheel thingey) that ultimately determine how effective the motor/platter isolation can be.

Also, Dertonarm brings up the point of clamping and the record/platter interface, and I agree that it's undeniable that the platter must be of sufficient mass to effectively sink the vibrational energy of the record. But as far as the proper way to make the record-platter interface, that's another issue. There seem to be obvious drawbacks with clamping (tolerances in record dimensions, flexibilty, and condition), vacuum hold-down (complexity, noise and reverse-side dirt-bonding), and mere gravity (poor coupling). I confess that I don't really have an opinion as to what the "ultimate" solution has to be . . . maybe we just play lacquers! Issue solved! :)

*** Well - the physical phenomenons regarding the turntable CAN and ARE fully understood. Unfortunately and apparently not by the majority of turntable designers. ***

Some of the phenomenons are well understood but many are not. Please explain why pulley material would be audible when used with a 70 lbs. platter. I don't have a clue what physics are involved for this case. I also am quite doubtful that even with the best equipment that this effect could be measured. I am not suggesting that this is magic. Something logical and scientific is going on, I just don't know what it is. I am sure that plenty of folks can come up with theories about why, but theories are not that same as really understanding the physics.

Oh, and yes this is a real effect that many folks have heard. Please lets not get into the subjective vs objective debates...