New Mag-Lev Turntable

How much do you think the platter weighs?

well thinking out loud this morning. It’s a "look Mom no hands" free floating design, so permanent magnets must be embedded in the platter in some pattern. The plinth portion is using electro magnetic forces. So one idea is; I am visualizing a repulsive force on the inner part of the platter, and some kind of metal ring embedded in the platter closer to the rim. This metal ring provides attraction to the plinth’s forces keeping the platter aligned. We don’t know what kind or amount of electro magnetic force is involved, but the platter floats very high. With cartridge shielding considerations, this makes me think the platter is therefore not very heavy. Without knowing what the actual materials are that the platter is made of, I am guessing, so let’s say a few pounds.

From the video you can clearly see a large variance where the platter deviates from flat. Now, whether that is from loose tolerances when manufacturing the platter or suspension effect is unknown.

I learned from personal experience, never to trust videos and pictures. Especially if you are buying a used boat 8^0.
Damn, when you go to see them, they always look worse than the pictures and videos.

Tolerances is IMO what the audiophile should focus on, when buying a packaged turntable setup (table, tonearm, cartridge). Tolerances are what separate the men from the boys. What should separate a 4 figure turntable package from a 5 figure one.

Example.
So a friend buys a 4 figure turntable package. Table, tonearm and cartridge. He levels the plinth feet to the point where the platter is level in the general area where the tonearm will travel. He then checks the level of the tonearm armboard which is fixed to the plinth. It is not on the same plane as his platter. His tonearm (the one that came with the package) does not have a self leveling system. What’s he going to do ? What happens when he goes to check the other half of the platter ? Is it on the same plane as the side the tonearm rides on ?
I think the person buying this Mag Lev turntable setup is not even thinking of tolerances. He or she is thinking this is so cool, I have to have one. In the end it is always the cartridge and some records that are the victims in a bad setup /design. The website says they have some folks using the product and providing input. Hopefully someone from the project team will have a look at the cartridge after XXX hours, to see what is really going on. To find out the truth. And this reminds me. if someone is having a cartridge re-tipped don’t forget to ask your re-tipper to check the wear pattern. To find out the truth.

ct0517, Yes tolerances are very important. The MagLev table in question is highly unlikely to have good tolerances at it's price point. Also highly unlikely to out perform other turntables at the same price point. All depends on how accurately the platter is spinning and floating. From the video it looks like it has some wobble. Do they have any specs for this table? Speed stability, wow and flutter would be nice to know.  

I'm sure they will sell plenty of them based on the fact that it is a novel and cool looking design. 

 

I also suspect the platter is light, perhaps very light, in order to minimize the magnetic field requirements. I also don’t think that some motion of the platter during play is necessarily a bad thing. The primary advantage of isolating the platter is the attenuation of structural vibrations in the frequency range that could excite the resonant frequency of the cartridge (and tonearm). Thus, low frequency motion of the platter, even visible motion, would be relatively innocuous as far as SQ goes since those very low frequencies are well below the 10-12 Hz resonant frequencies of the cartridge and tonearm. And they would be well below audio frequencies

Geoff, that is true but any extra motion is not ideal. Since there is no spindle how accurately does it spin in one location? Does the platter always align to the same spot? If not this could change the pivot to spindle difference each time. When aligning a cartridge with the platter at rest, will it float in the exact same horizontal location as it does when resting? That could cause an alignment problem. This design may help one design problem but it also creates new design problems as well.

On that same track, in order to align the cartridge correctly you would need to put blocks under the platter to raise it to the same height as when it is spinning. How would you accurately place the platter at the same place it spins when floating? That would be very difficult it not impossible.