Interesting turntable

[[email protected]]

https://maglevaudio.com

If the link doesn't work search maglev turntable

May eliminate rumble, but eccentricity must be a challenge.

M

[geoff]

On 2/07/2017 6:01 AM, wrote:
>
>
>
> https://maglevaudio.com
>
> If the link doesn't work search maglev turntable
>
> May eliminate rumble, but eccentricity must be a challenge.
>
> M
>

Yeah but you'd need a piezo crystal cartridge.

geoff

[Chuck H.]

On Sun, 2 Jul 2017 10:55:12 +1200, geoff >
wrote:

>On 2/07/2017 6:01 AM, wrote:
>>
>>
>>
>> https://maglevaudio.com
>>
>> If the link doesn't work search maglev turntable
>>
>> May eliminate rumble, but eccentricity must be a challenge.
>>
>> M
>>
>
>Yeah but you'd need a piezo crystal cartridge.

They come with an Ortofon magnetic.
>
>geoff

[geoff]

On 2/07/2017 4:14 p.m., Chuck H. wrote:
> On Sun, 2 Jul 2017 10:55:12 +1200, geoff >
> wrote:
>
>> On 2/07/2017 6:01 AM, wrote:
>>>
>>>
>>> https://maglevaudio.com
>>>
>>> If the link doesn't work search maglev turntable
>>>
>>> May eliminate rumble, but eccentricity must be a challenge.
>>>
>>> M
>>>
>> Yeah but you'd need a piezo crystal cartridge.
> They come with an Ortofon magnetic.
>> geoff

So it seems. And the the levitation and rotation is achieve how ?

Not convinced it's for real.

geoff

[Gray_Wolf]

On 7/1/2017 11:14 PM, Chuck H. wrote:
> On Sun, 2 Jul 2017 10:55:12 +1200, geoff >
> wrote:
>
>> On 2/07/2017 6:01 AM, wrote:
>>>
>>>
>>>
>>> https://maglevaudio.com
>>>
>>> If the link doesn't work search maglev turntable
>>>
>>> May eliminate rumble, but eccentricity must be a challenge.
>>>
>>> M
>>>
>>
>> Yeah but you'd need a piezo crystal cartridge.
>
> They come with an Ortofon magnetic.
>>
>> geoff

How are the applying the drive force to the turntable?

[Phil Allison[_4_]]

geoff wrote:

---------------------

>
> And the the levitation and rotation is achieve how ?
>
> Not convinced it's for real.
>
>

** Many things about it scream scam - but ....

https://www.kickstarter.com/projects/245727224/mag-lev-audio-the-first-levitating-turntable/posts/1898322

Only 12W consumption so it must use permanent magnets.


..... Phil

...... Phil

[Trevor]

On 2/07/2017 3:11 PM, geoff wrote:
> On 2/07/2017 4:14 p.m., Chuck H. wrote:
>> On Sun, 2 Jul 2017 10:55:12 +1200, geoff >
>> wrote:
>>> On 2/07/2017 6:01 AM, wrote:
>>>> https://maglevaudio.com
>>>>
>>>> If the link doesn't work search maglev turntable
>>>>
>>>> May eliminate rumble, but eccentricity must be a challenge.
>>>>
>>> Yeah but you'd need a piezo crystal cartridge.
>> They come with an Ortofon magnetic.
>
> So it seems. And the the levitation and rotation is achieve how ?
>
> Not convinced it's for real.

Who cares. Even if it is you can be certain it's just an expensive
gimmick for people with more money than sense.
(So I guess the vinyl nostalgia market is a perfect target. :-)
The low end Ortofon OM5E as used in most budget turntables gives you an
idea of the performance to expect for a start.

Trevor.

[Don Pearce[_3_]]

On Sun, 2 Jul 2017 17:04:01 +1000, Trevor > wrote:

>On 2/07/2017 3:11 PM, geoff wrote:
>> On 2/07/2017 4:14 p.m., Chuck H. wrote:
>>> On Sun, 2 Jul 2017 10:55:12 +1200, geoff >
>>> wrote:
>>>> On 2/07/2017 6:01 AM, wrote:
>>>>> https://maglevaudio.com
>>>>>
>>>>> If the link doesn't work search maglev turntable
>>>>>
>>>>> May eliminate rumble, but eccentricity must be a challenge.
>>>>>
>>>> Yeah but you'd need a piezo crystal cartridge.
>>> They come with an Ortofon magnetic.
>>
>> So it seems. And the the levitation and rotation is achieve how ?
>>
>> Not convinced it's for real.
>
>Who cares. Even if it is you can be certain it's just an expensive
>gimmick for people with more money than sense.
>(So I guess the vinyl nostalgia market is a perfect target. :-)
>The low end Ortofon OM5E as used in most budget turntables gives you an
>idea of the performance to expect for a start.
>

The whole exercise is simply one turd-polishing. Once you have moved
beyond a Dansette, you've surpassed all the quality possibilities of
vinyl.

d

---
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[Mike Rivers[_2_]]

On 7/2/2017 1:11 AM, geoff wrote:

> And the the levitation and rotation is achieve how ?

Permanent magnets. It runs. It plays records. I saw one at CES this
year. I think it's more for amazing and amusing your friends than for
being a superior way to play records, though I expect that the isolation
from vibration is excellent. Just the thing for playing your old Bob
Dylan or Aerosmith LPs during an earthquake.



--

For a good time, call http://mikeriversaudio.wordpress.com

[Trevor]

On 2/07/2017 9:10 PM, Mike Rivers wrote:
> On 7/2/2017 1:11 AM, geoff wrote:
>
>> And the the levitation and rotation is achieve how ?
>
> Permanent magnets. It runs. It plays records. I saw one at CES this
> year. I think it's more for amazing and amusing your friends than for
> being a superior way to play records,

I don't think there is any doubt about that.


> though I expect that the isolation from vibration is excellent.

I wouldn't be sure about that. The magnetic coupling must be pretty good
for it to work at all, which means most vibration should also be pretty
well coupled.

Trevor.

[Phil Allison[_4_]]

Trevor wrote:

-----------------

> Mike Rivers wrote:
> > geoff wrote:
> >
> >> And the the levitation and rotation is achieve how ?
> >
> > Permanent magnets. It runs. It plays records. I saw one at CES this
> > year. I think it's more for amazing and amusing your friends than for
> > being a superior way to play records,
>
> I don't think there is any doubt about that.
>
>
> > though I expect that the isolation from vibration is excellent.
>
> I wouldn't be sure about that. The magnetic coupling must be pretty good
> for it to work at all, which means most vibration should also be pretty
> well coupled.
>
>
** In a video of the unit, the platter is seen bouncing about for many seconds when displaced - much like a Lin Sondek's platter does.

The Sondek has soft coil springs supporting a heavy alloy platter and its sub frame. As a result, it has really excellent isolation from floor vibrations.

So my bet is Mike is right.



..... Phil

[geoff]

On 3/07/2017 12:58 AM, Phil Allison wrote:

>>
> ** In a video of the unit, the platter is seen bouncing about for many seconds when displaced - much like a Lin Sondek's platter does.
>
> The Sondek has soft coil springs supporting a heavy alloy platter and its sub frame. As a result, it has really excellent isolation from floor vibrations.
>
> So my bet is Mike is right.
>
>
>
> .... Phil
>
>
>
>

Would be better if the tone arm, rigidly-coupled to the platter, was
equally isolated. Cos otherwise any vibration etc with get to the
cartridge by that route.

And what about the drive magnetics ?

The opportunity to 'pre-order' says it all for me.

geoff

[[email protected]]

Digital motor my guess.

[Phil Allison[_4_]]

geoff wrote:

--------------------

> Phil Allison wrote:
>
> >>
> > ** In a video of the unit, the platter is seen bouncing about for many seconds when displaced - much like a Lin Sondek's platter does.
> >
> > The Sondek has soft coil springs supporting a heavy alloy platter and its sub frame. As a result, it has really excellent isolation from floor vibrations.
> >
> > So my bet is Mike is right.
> >
>
>
> Would be better if the tone arm, rigidly-coupled to the platter,
>

** Err - you mean base.

> was
> equally isolated. Cos otherwise any vibration etc with get to the
> cartridge by that route.
>

** In practice, almost none does and then creates no output.

The famous Sondek has the same arrangement.

https://en.wikipedia.org/wiki/Linn_Sondek_LP12


> And what about the drive magnetics ?
>

** That is still a mystery.

Electromagnetics could be used, it needs little power.


> The opportunity to 'pre-order' says it all for me.


** Production is still not under way.

AFAIK it is intended that all sales be done on-line with the makers in Slovenia.



..... Phil

[geoff]

On 3/07/2017 1:29 PM, Phil Allison wrote:
> geoff wrote:
>
> --------------------
>
>> Phil Allison wrote:
>>
>>>>
>>> ** In a video of the unit, the platter is seen bouncing about for many seconds when displaced - much like a Lin Sondek's platter does.
>>>
>>> The Sondek has soft coil springs supporting a heavy alloy platter and its sub frame. As a result, it has really excellent isolation from floor vibrations.
>>>
>>> So my bet is Mike is right.
>>>
>>
>>
>> Would be better if the tone arm, rigidly-coupled to the platter,
>>
>
> ** Err - you mean base.

Base and platter. If the base/tonearm is vibrating and the platter
isn't, then output results from cartridge. If tonearm and platter on
the same structure then any excitation is to both and is therefore in
unison (apart from from the disc !), then likely less output from the
cartridge.

My olde Garrard 301/SME had the whole base on a board that was itself
isolated from the casing and whatever it stood on - in my case a heavy
wooden table with legs standing on concrete piles into the ground below,
not touching the floor ! (Extreme and probably pointless, yes, but I was
building the house and there was little actual effort involved./..)

>
>> was
>> equally isolated. Cos otherwise any vibration etc with get to the
>> cartridge by that route.
>>
>
> ** In practice, almost none does and then creates no output.
>
> The famous Sondek has the same arrangement.

I think you'll find the tone-arm and platter are on the same suspended
sub-chassis. Mine friend's was.


> https://en.wikipedia.org/wiki/Linn_Sondek_LP12
>
>
>> And what about the drive magnetics ?
>>
>
> ** That is still a mystery.
>
> Electromagnetics could be used, it needs little power.

Electromagnetics and magnetic cartridge ...

geoff

[Phil Allison[_4_]]

Geoff wrote:

---------------

>
> >
> > ** In practice, almost none does and then creates no output.
> >
> > The famous Sondek has the same arrangement.
>
> I think you'll find the tone-arm and platter are on the same suspended
> sub-chassis. Mine friend's was.
>

** On reflection, I think you are right.

I never owned a Sondek but used a belt drive TT and uni-pivot arm mounted on inch thick Perspex.

The Perspex slab was suspended on three be-hive springs and wobbled like jelly if bumped. The floor isolation was amazing.


..... Phil

[geoff]

On 3/07/2017 4:50 PM, Phil Allison wrote:
> Geoff wrote:
>
> ---------------
>
>>
>>>
>>> ** In practice, almost none does and then creates no output.
>>>
>>> The famous Sondek has the same arrangement.
>>
>> I think you'll find the tone-arm and platter are on the same suspended
>> sub-chassis. Mine friend's was.
>>
>
> ** On reflection, I think you are right.
>
> I never owned a Sondek but used a belt drive TT and uni-pivot arm mounted on inch thick Perspex.
>
> The Perspex slab was suspended on three be-hive springs and wobbled like jelly if bumped. The floor isolation was amazing.
>
>
> .... Phil
>


Sounds like a Mitchell Focus I once had,. But then again I think that
was glass.

geoff

[Scott Dorsey]

Phil Allison > wrote:
>geoff wrote:
>
>---------------------
>
>>
>> And the the levitation and rotation is achieve how ?
>>
>> Not convinced it's for real.
>>
>>
>
>** Many things about it scream scam - but ....
>
>https://www.kickstarter.com/projects/245727224/mag-lev-audio-the-first-levitating-turntable/posts/1898322
>
>Only 12W consumption so it must use permanent magnets.

Yes. It uses permanent magnets whose field falls off with the 4th power
of the distance so the resistance increases dramatically with deflection.
Which is good, at least in terms of the spring side of the mass-spring system.

The problem with this implementation is that it doesn't have enough mass, so
once you set it moving it bounces back and forth pretty severely at the
system's resonant frequency.

Doesn't anyone build sand tables anymore?
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."

[John Williamson]

On 03/07/2017 13:54, Scott Dorsey wrote:

> Doesn't anyone build sand tables anymore?
>
Werll, guv'nor. It's like this. You just can't get decent sand nowadays.
<Sucks teeth> Costs an arm and a leg, it does... <Walks off, shaking
head gently>

--
Tciao for Now!

John.

[Les Cargill[_4_]]

Scott Dorsey wrote:
> Phil Allison > wrote:
>> geoff wrote:
>>
>> ---------------------
>>
>>>
>>> And the the levitation and rotation is achieve how ?
>>>
>>> Not convinced it's for real.
>>>
>>>
>>
>> ** Many things about it scream scam - but ....
>>
>> https://www.kickstarter.com/projects/245727224/mag-lev-audio-the-first-levitating-turntable/posts/1898322
>>
>>
>>
Only 12W consumption so it must use permanent magnets.
>
> Yes. It uses permanent magnets whose field falls off with the 4th
> power of the distance so the resistance increases dramatically with
> deflection. Which is good, at least in terms of the spring side of
> the mass-spring system.
>
> The problem with this implementation is that it doesn't have enough
> mass, so once you set it moving it bounces back and forth pretty
> severely at the system's resonant frequency.
>
> Doesn't anyone build sand tables anymore? --scott
>

Not if they can help it.

--
Les Cargill

[Phil Allison[_4_]]

Scott Dorsey wrote:

------------------------


> >
> >** Many things about it scream scam - but ....
> >
> >https://www.kickstarter.com/projects/245727224/mag-lev-audio-the-first-levitating-turntable/posts/1898322
> >
> >Only 12W consumption so it must use permanent magnets.
>
> Yes. It uses permanent magnets whose field falls off with the 4th power
> of the distance so the resistance increases dramatically with deflection.
> Which is good, at least in terms of the spring side of the mass-spring system.
>
> The problem with this implementation is that it doesn't have enough mass, so
> once you set it moving it bounces back and forth pretty severely at the
> system's resonant frequency.
>
>

** Adding mas to the platter would only make the bouncing worse.

The problem is lack of damping.

How the heck do you damp something that floats ?


...... Phil

[geoff]

On 4/07/2017 1:34 p.m., Phil Allison wrote:
>
> How the heck do you damp something that floats ?
>
>

Enough of this toilet humour !

geoff

[[email protected]]

On Sunday, July 2, 2017 at 9:29:29 PM UTC-4, Phil Allison wrote:
> geoff wrote:
>
> --------------------
>
> > Phil Allison wrote:
> >
> > >>
> > > ** In a video of the unit, the platter is seen bouncing about for many seconds when displaced - much like a Lin Sondek's platter does.
> > >
> > > The Sondek has soft coil springs supporting a heavy alloy platter and its sub frame. As a result, it has really excellent isolation from floor vibrations.
> > >
> > > So my bet is Mike is right.
> > >
> >
> >
> > Would be better if the tone arm, rigidly-coupled to the platter,
> >
>
> ** Err - you mean base.
>
> > was
> > equally isolated. Cos otherwise any vibration etc with get to the
> > cartridge by that route.
> >
>
> ** In practice, almost none does and then creates no output.
>
> The famous Sondek has the same arrangement.
>
> https://en.wikipedia.org/wiki/Linn_Sondek_LP12
>
>
> > And what about the drive magnetics ?
> >
>
> ** That is still a mystery.
>
> Electromagnetics could be used, it needs little power.
>
>
> > The opportunity to 'pre-order' says it all for me.
>
>
> ** Production is still not under way.
>
> AFAIK it is intended that all sales be done on-line with the makers in Slovenia.
>
>
>
> .... Phil

I say it's more complex than just magnets, otherwise someone would have produced one years ago. Besides, it'd be too unstable with just magnets.

Too much ripple in the DC would be sent to the platter, 120Hz. vibrations! :)

Jack

[Don Pearce[_3_]]

On Mon, 3 Jul 2017 18:34:15 -0700 (PDT), Phil Allison
> wrote:

>Scott Dorsey wrote:
>
>------------------------
>
>
>> >
>> >** Many things about it scream scam - but ....
>> >
>> >https://www.kickstarter.com/projects/245727224/mag-lev-audio-the-first-levitating-turntable/posts/1898322
>> >
>> >Only 12W consumption so it must use permanent magnets.
>>
>> Yes. It uses permanent magnets whose field falls off with the 4th power
>> of the distance so the resistance increases dramatically with deflection.
>> Which is good, at least in terms of the spring side of the mass-spring system.
>>
>> The problem with this implementation is that it doesn't have enough mass, so
>> once you set it moving it bounces back and forth pretty severely at the
>> system's resonant frequency.
>>
>>
>
> ** Adding mas to the platter would only make the bouncing worse.
>
> The problem is lack of damping.
>
> How the heck do you damp something that floats ?
>

There is plenty of magnetic field there. All you need is some copper
or aluminium to generate eddy currents.

d

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[Scott Dorsey]

Phil Allison > wrote:
> ** Adding mas to the platter would only make the bouncing worse.
>
> The problem is lack of damping.

Adding mass would make it bounce at a lower and lower frequency, so you could
get it down to very long periods. But agreed, the lack of damping is the
worst problem.

The more I think about it, though, the more I think that the nonlinearity of
the repulsion means you can't easily model it simply as a damped spring
system, since it's nearly "bouncing off the stops" at the extremes with a
low-resistance band in the middle. I think this is actually going to be
worse than spring coupling if one were to do the math.

> How the heck do you damp something that floats ?

Put it underwater! Or in motor oil! Or in a sulfur hexafluoride atmosphere!
--scott

Or sand...
--
"C'est un Nagra. C'est suisse, et tres, tres precis."