MAG-LEV Audio – Levitating Turntable | Hacker News Reader

MAG-LEV Audio – Levitating Turntable

maglevaudio.com

35 pointsevo_943 comments

That's just decorative. The real advance in record players is IRENE.[1] This is an optical record player. It takes a 3D image of the recording surface with a confocal microscope. That's used to create a 3D model, which is then "played" in simulation to get out the audio. The Library of Congress uses these to recover old records and cylinders. They can even put a broken record back together.

[1] https://news.lib.berkeley.edu/project-irene-lawrence-berkele...

Killer marketing idea - an audio product with a feature that looks like it could conceivably improve audio quality in some way, but make absolutely zero claims about whether it does or not. Don't pay for any research, don't stretch the truth in the marketing copy, just let the audiophiles buy it and argue about whether it has any effect. Everybody wins!

They, and each of the reviews they quote, carefully avoid any mention of any auditory benefits. Are there none? To me, the real reasons for doing this would be

1) to isolate the turntable from floor vibrations. Walking or stomping nearby, or even closing a door, can be picked up and amplified as a rather unpleasant booming low-frequency sound. And jumping hard enough nearby can even make the needle skip.

and possibly

2) to eliminate the mechanical motors and thereby another source of noise or interference. All while possibly achieving better or more consistent control of rotation speed?

So, why are any such claims so scrupulously avoided? Because it doesn't accomplish either of those things? Because their experience with phonographs is so shallow they don't even know those issues people might care about? It's weird...

It seems to me like the turntable is still connected to vibrations, just magnetically rather than mechanically.

Yes I was wondering about that. Magnetic force follows a power law, so you would think the upward force, once it's at the point of balancing the weight of the turntable, might be almost as rigid as a solid connection. Although it would be less so, the lighter the turntable was, for a given magnetic field strength. But then you would probably incur a "jumpiness/bounciness" penalty. Rather an interesting design problem actually.

Yes, and also turbulence from the wind.

Well, it's a mass and a nonlinear spring connection. The result should be a lowpass filter.

It could be better because it seems hard to make low-pass solids at audio range and beyond: for example, while you can easily make a spring which has low pass behavior in the few Hz range, the spring itself is made of metal and conducts sound normally. I guess you have felt pads and foam (which have thin strands and large number of interfaces for sound to reflect). The magnetic force however should retain its springy behavior up to arbitrarily high frequencies.

They could increase the mass of the platter so that inertia helps with isolation. They say it's 2.2kg and to me that "feels" heavy, but my experience is only with retail-grade turntables and I don't know where that fits in with high-end gear.

An SL-1200 weighs in at about 30 lbs (13.5kg).

Not sure what the weight of the platter itself is off the top of my head.

1.48kg platter on a sl-1210mk2

I don't have data to back this up, but I suspect the main issue with needle skip is from vibrations being transmitted through (and maybe amplified along?) the arm. Since the arm is still mounted to the base, it could be that levitating the platter does zilch for vibrations. I wonder what it would take to levitate the arm too, and just have a flexible cord hanging down to pass along the signal?

Eliminating needle skip was the first thing that came to my mind too, there's gotta be a reason they don't even mention it.

I'll preface this by saying any attention paid to the performance of record players is an absolute waste of effort, in my opinion.... buuuut.

I think that there's a different problem for each component. The turntable introduces vibrations vertically (which seems less important to me, except it could affect stereo), and the arm introduces them horizontally.

It's just another way of doing the "bearing". Normally, that's a bit of machining with extremely tight tolerances and a single point of very high pressure contact, either ball-on-ball or cone-on-cone. I had a table about thirty years or so back now - a Revolver - that took a full three days for the platter/spindle to bottom out in the bearing when it was installed. (And while it was "hi-fi", it wasn't nearly high-end. An audiophile would have called it "entry level".)

It looks cool. The very first sentence on the page is "MAG-LEV Audio's ML1 Turntable visually enhances the experience of listening to vinyl records by levitating the platter."

> to isolate the turntable from floor vibrations. Walking or stomping nearby, or even closing a door, can be picked up and amplified as a rather unpleasant booming low-frequency sound.

The so called "rumble filter" was a common feature of amplifiers from the 80s. Vinyl may have been reborn, but the surrounding ecosystem has not, so most "modern" record player systems are quite inferior to those of the past. Ironic.

Interesting development of the standard turntable, though the aspect that it still utilises a stylus that makes contact with the record is the area I'm looking at some technological love.

With that, a laser or photo sensor that reads the record surface would be an advancement and preserve records from wear and tear that a stylus needle will induce.

Maybe the next version will embrace such technology.

Reference - https://en.wikipedia.org/wiki/Laser_turntable

I've listened to several laser turntables. The audio quality is quite bad. The main problem is that a stylus, in the process of traveling through the groove, pushes dust and dirt out of the way, so that it can make direct contact with the record.

The laser does no such thing, and so there is significantly more noise in the playback, unless your record is perfectly clean, which is essentially impossible.

It also will not play records which are colored or transparent. Only black will work.

Thank you, the aspect about dust and dirt would be an easy overlook (as I did) and one which could affect quality. Though I'm sure an issue that can be engineered away.

I am guessing that this turntable won't need isolation dampers to prevent needle jumping?!

But on a more serious note, I have always been intrigued as to why the majority of turntables still seem to rely on a belt drive system that goes back many decades. Surely modern technology has come up with a reliable direct drive motor that can better regulate the torque and RPM requirements of the platter, as well as offer better stability?

Is it similar to the 'digital versus vacuum tubes' type arguments that are prevalent on guitar amp discussion forums?

Of course, you can find direct drive brushless motors on higher-end models, but the truth is that they're more expensive, so when you're trying to make a sale to most customers who just want to spend a couple hundred bucks, they don't care about direct drive.

Direct drive is certainly better and more reliable than any belt system. Very low flutter and wow.

Not to mention DJing requires direct drive for the better torque leading to lower latency for beat matching and scratching and the like.

It's perfectly possible to beat match on belt drive but yes, not something you'd ever want to use over direct.

No. Direct-drive setups are prone to "cogging", where increasing the mass of the platter to make it a sufficiently effective flywheel verges on the ridiculous. (This being high-end audio, you can take it for granted that ridiculous has been striven for and achieved on more than one occasion.) A belt drive has smoothing built in, though it still requires a massive platter, a motor with enough torque and a belt that isn't actually sloppy/springy. You can get to the same place with less mass and at lower cost.

I use a late-70s direct drive turntable (CEC DD-8200), from before the era of fancy quartz lock tables. There is no cogging at all, speed stability is exemplary and the platter is not some sort of 10kg monstrosity.

The whole thing about cogging in DD turntables was a rumor started by European boutique manufacturers, because they couldt compete with the R&D budgets and engineering employed by big companies like Technics/National, Sony, Denon, CEC, Pioneer, Mikro Seiki and others. It's a non-issue on any decent DD table.

Cogging only happens in bargain basement tables, such as the cheapest modern USB lightweight plastic DJ-marketed tables. Super OEM tables are fine though.

It similar to the 'digital versus vacuum tubes'.

Many people don't realize that you can turn a technics 1200/1210 into a great hi-fi turntable. They are highly upgradable.

People just assume because these decks were designed for DJ'ing they can't possibly sound good.

I used to be a member of this forum: https://theartofsound.net. There are guys on there who have spent a few thousand upgrading their technics. New tonearms, platters, motors, and other stuff. And they thought their upgraded 1200/1210 sounded better than belt drive decks which were 4X or 5X more expensive.

I have an upgraded Technics Mk5. I've only spent a few hundred on it but it's the best sound deck I've ever heard.

There is no point in "upgrading" an SL-1200 Mk2 and onwards. The motor, tonearm and all associated components are already top of the line. But because they were made by a big corp, audiophiles erroneously think they're not high quality.

It's really cool. I'd like to see one but not buy one.

Very cool if you are a rich audio geek who wants to impress fellow vinyl nerds with your conspicuous consumption. I'll probably have to wait 10-15 years until some cheap Chinese knock off is produced (if ever).Or better yet I think I'll go back and mod my USB turntable to work with a raspberry Pi as a virtual turntable.

They are likely continuously, dynamically monitoring and adjusting electromagnets, to work around Earnshaw's Theorem [1]. It isn't possible to statically levitate with magnets, so I'm interested in finding out the hardware mechanism they're using for the monitoring, as well as their provisions for the turntable "crashing" out of the levitation fields. I'd love to find server fans that use the same tech, perhaps condensing the logic they use into FPGAs at first and then ASICs, and practically never have to worry about replacing a server fan again (the fans will wear out, but on a much longer timeline).

[1] https://en.wikipedia.org/wiki/Earnshaw's_theorem

Earnshaw's Theorem does not apply to moving magnets. A spinning magnetic disc can levitate over static magnets.

As much as I'm liking sounding like I have a clue about the theorem… my brother had a Levitron and I played with it.

https://en.wikipedia.org/wiki/Levitron

I had one of those too. I don't think "stable" is really the right description, though - it generally wobbled all over the place. It didn't just shoot off straight away though so there's definitely some kind of attractor stuff going on.

Edit: Although reading the wiki link, it sounds more like the instability was just due to it requiring a very specific speed.

a turntable is not a static configuration

At least it seems like they're being honest about the fact that it's a cool-looking gimmick. I expected some audiophile nonsense about isolating the record from seismic micro-tremors and using levitation coils to cancel electro-audiophonic interference from the Earth's magnetic field.

Looks cool. I don't know why anyone would spend so much money on such an outdated technology, though.

Back in the 90s I’m sure I remember something like this in the market.... I was a small-time DJ and liked to keep across the new AV gear.

I also certainly remember magnetic levitating AV stands to minimise distortion. It was a bit of a gimmick, given the cables would still introduce vibrations. But I’m sure some people paid big dollars for them.

"visually enhances"

That's a lot of trouble to go to merely visually enhance the audio experience.

Skrillex will take what he can get.

What I find odd is that they're levitating the platter.

I would have been more interested in a design which levitated the tonearm, allowing for less drag as the tonearm pivots.

The weight behind the tonearm 'levitates' it across a fulcrum, and this is adjustable on a quality turntable. The needle should have neither more nor less drag than absolutely necessary.

The real question is: Can you scratch with it?

I know this is probably a joke, but I really can't imagine it would be good at that at all.

Oh look audiophile bullshit

Nowhere does the manufacturer claim that audio quality is improved. The first sentence of the product description says that it looks good.

They're being quite honest.

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