mag-lev-turntable

Probably For Real. Too much/many "other" sources and information out there.

Interesting idea. One does wonder how the centering and leveling functions work. I can figure out how they handle rotation. A half-price for pre-purchase is not a half-bad deal given it comes with an arm and cartridge.

Peter Wieck Melrose Park, PA

Oh, boy! Did you see how HIGH they levitate the platter? Geez, I have strong doubts it can be stable at that height. Also, the thing must have an insanely strong external magnetic field.

Now, the only way I know one-sided levitation at low speeds can work is with something that TOTALLY excludes flux lines, ie. a superconductor.

So, the only way this thing could work is with a spinning Halbach array under the platter (which would play HELL with a magnetic phono cartridge) or massive high-field magnets underneath and a room temperature superconductor in the platter. Hmmm, can't buy that yet...

I know of no way to repel something ordinary with a steady magnetic field, although with strong tapered AC fields, it is possible to repel a conductor. I've seen this done with a big 3-phase AC motor stator and an aluminum platter. But, the motor draws insane current and the platter gets hot fast.

Brooklyn? As in Brooklyn bridge? Yup, sounds pretty appropriate, I'm very skeptical of this one. I think it probably CAN be done, but not as a practical device, capable of operating right next to a megnetic phono cartridge.

Jon

I didn't see that they cited the numbers of the patent(s) that they say they have.

The other trick which puzzles me, is how they keep the magnetic levitation/centering/rotation field from being picked up by the cartridge, or keeping the magnitude of the pick-up down below the noise floor of the phono preamplifier.

Years ago, some of the Grado cartridges had a bad reputation for hum when used with certain turntables - the stray fields from the AC motors were picked up by the coils in the cartridge.

Lovely ide, but I'd want to know more... Presumably the huge floating height in the "photo" is merely to make it obvious, rather than being enough to de-couple a major earthquake?

And how is the speed controlled?

Mike

I see it as a novelty. It may well work and may be worth more than the sum of its parts but is it worth it ?

And forget DC coupling in the amp it drives. Levitated that high the magnet ic fields needed to drive it will be substantial and be picked up by the ca rtridge. If it is three phase drive that works out to about 1.7 Hz, which i s quite low. However if you buy such an expensive turntable you are likely to have an expensive phono preamp which may be DC coupled. So then you have to use some sort of filter to get that noise out.

I don't generally go for these pay before they are even built schemes. Ther e is a reason that some company somewhere is not already doing this. What i s half price ? Ten grand ?

That is why I am not in the one for Red Pataya, which is like an Arduino bu t supposedly more versatile, or something.

And I see no reason in having a turntable that is higher fidelity than the lathe on which the master record was cut.

I am not necessarily saying the people are crooks, but it is someone's pet project and they do expect to make money. There is another one out there, a vertical turntable. There are people putting money into that as well and i t is not a really good idea. It is one hell of a novelty, as this is and if you got the money honey, go for it. Impress your friends and enemies as we ll.

Vertical record players have been around since at least the 1940s... Seeburg jukeboxes all used vertical storage and play of both 78s (1940s) and 45s right to the end - early 1990s.

Sony used a vertical player for their CDs.

John :-#)#

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The best you can do with vinyl is pretty poor; why bother?

Plus, rumble has not been a problem on "ordinary" turntables (well, decent-quality ones) for quite a while.

Isaac

Perhaps they use a ceramic cartridge. The sound would suffer, but it would still look pretty cool.

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Jim

people putting money into that as well and it is not a really good idea. It is one hell of a novelty, as this is and if you got the money honey, go for it. Impress your friends and enemies as well.

I'm sure a vertical turntable was marketed decades ago. I don't remember the supposed advantage, though...

Mike.

an

ith

I have experienced these magnets directly - when we were in China, the nove lty shops sold a device with what amounted to a metal puck, about the size of a hockey puck but half the thickness that could be suspended above a pla tform if "heads" or was very nearly impossible to remove from the platform except by sliding if "tails". Variations included a shaft that could be sp un in suspension over a bed attached to the platform and another that could be twirled.

When we tried to bring it back to the US in our checked baggage, we were ca lled to the front of the plane and informed that these things were powerful enough to interfere with aircraft navigation systems - and that we would h ave to either get off the aircraft and mail it, or give it up. We gave it u p.

In any case, I would have no difficulty at all believing Neodymium magnets within the platter with a rotating field developed in the plinth reaching t hat distance. And, it would have the additional effect of 'centering' the p latter as well. The platter *will* be quite heavy.

Now, one more beneficial effect of this system: The field will be, effectiv ely, two nested donuts, and they could be rather small relative to the 12" platter given the power of the static field (in the platter) - perhaps as l ittle/small as 6". At that size, the platter would be a shield for the cart ridge both magnetically and in rF. Note that the cartridge is always *ABOVE

• the field with the platter between it and that field.

Not that I am going to line up to purchase that TT. I am hooked on linear t racking arms - and unless/until that happens, it is only a neat trick, no m ore.

Peter Wieck Melrose Park, PA

One advantage was that they could be built into boomboxes and an arm could be mounted on the front and the back. (No need to flip the record) I remember when they first Sharp samples showed up at Best Buy. They were monstrosities that I thought wouldn't sell and I was right.

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let's see, how many things can go wrong here.

1) the stylus has weight required for proper tracking. It will want to tilt the platter, and the torque will vary from edge to center.

2) there's friction at the stylus, making the platter want to rotate around the point of contact.

3) the base is still coupled to the platter through the magnetic field. Vibrations will still be coupled to the platter.

4) better have a UPS. You don't want that platter crashing down when the power goes out.

5) that large of a magnetic field wont interfere with the cartridge?

6) a rotating magnetic field driving the platter will introduce just as much wow and flutter as is introduced by the motor of a direct drive turntable.

7) an open window or a fan could easily blow that platter around creating even more distortion.

And that's without putting much thought into it. But it seems they've already exceeded their goal and have more than $400,000.

dl=0

This is my wildly speculative speculation on how this system could work and be effective. Some points:

a) Neodymium magnets are wildly powerful. And can be shaped more efficientl y than many other materials. b) By offsetting the suspension rings as shown, the forces centering and ke eping the platter level would be very strong - certainly stronger than most suspension springs for that matter. c) And there would be negligible elastic forces - that is, no wobble or bou nce. That window fan would not have a chance. Damping, similarly. d) The wow and flutter issue, though very real, would be pretty much elimin ated by the mass of the platter (considerable) coupled with the very neglig ible mass of the drive motor. e) As the platter is essentially frictionless, it would not take much to ke ep it running once started. I would anticipate a few seconds of start-up, b ut after that, gyroscopic effects would contribute to leveling and to speed control. The couple of grams on the stylus, again, would not have a chance . f) The soft shut-down is already addressed. There is an on-board soft shut- down capacity that will raise the posts and lift the stylus. g) As to magnetic fields - consider that both the suspension field and the drive fields are static relative to each other. Meaning that there will be very little generated by way of stray fields, and that the platter, if prop erly designed, will be enough to shield the cartridge. Considering what goe s on inside my HK/Rabco without ill effect, or my Revox B295, this would be low on my worry-scale.

Again, this is a neat trick, not something I intend to purchase. But a neat trick that appears to be both possible and reasonable to execute.

Peter Wieck Melrose Park, PA

Still seems like it would be a lot easier to use direct drive and air bearings. But since it's already been done, there wouldn't be as much money in it.

Seems like a solution in search of a problem. In a world filled with people who now listen to MP3s or other forms of compression I wonder how many folks in the world would want this even if it does all it promises.

And, I'm willing to bet that in a double blind test with even quality tables at the lower end of the spectrum, this toy's superiority would not be discernible, even if "audiophiles" do avoid double blind tests.

Just watched this video:

There is a LOT of platter movement beyond the rotating moments going on here. Check 0:42

tables at the lower end of the spectrum, this toy's superiority would not be discernible, even if "audiophiles" do avoid double blind tests.

Just been watching on TV a single-blind test of three turntables costing approx order of magnitude amounts apart. The two listeners claimed to put then in order of merit per cost!

Mike.

Rogers Ritter published on a low-rumble magnetic suspension audio turntable back in the seventies; he was using magnetic attraction, and some active feedback, and was more interested in physics (gravity research) than audio. If these folk have a patent, that's not what they're doing.

What puzzles me, is how there's enough reliable torque on the rotor.

To levitate a light platter at low speeds, you could get use fixed magnets and a 2-d conductor (pyrolitic graphite, doped, is light and has conductivity better than copper). Levitation distances of a few millimeters would work, after spin-up. No torque, though, if that's the only trick used.

Third possibility fixed magnets, spinning conductor. And smaller gap than the pic shows.

Lots of info on the magnet-bearing subject:

I wonder how it will work on my old warped vinyl records?

Keeping it centered to within half a track width or less might be difficult with the needle applying a side force which is probably not consistent across the tone arm swing. I expect to see a levitated tone arm in the next version.

Fighting gravity seems to be the current obsession in turntables:

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