Magnetic levitation feet


https://www.ebay.co.uk/itm/184656986303?chn=ps&mkevt=1&mkcid=28

What do we think of these isolation devices, manufactured by Michell - of 60s/70s Transcriptors/A Clockwork Orange fame - and others?

Michell designed them for un-sprung turntables like the Transcriptors.  Two powerful magnets of washer form are arranged to repel each other, the upper one placed to slide on a vertical pillar.

They are nicely manufactured and presented and reasonably priced at £210 for a set of three (conforming to the old Linn triangular support mantra).  Some of the competitor examples are a bit cheaper.

I have not heard systems using them.  Has anyone?

How do they perform under CD players, amplifiers, DACS and other electronic components?
128x128clearthinker
@vinylzone,

I guess it must be adjustable as most turntable designs attempt to put their centre of gravity somewhere between the arm pillar and the spindle, don’t they?


@chakster,

Good link, again showing just how long these things have been around.

Mark Wheeler has been investigating the relationship between good sound and unwanted resonances over at TNT for many years now - but never in a boring manner.


"Way back in the annals of this vibration control Odyssey I quoted William Blake’s idea that we cannot know how far we should go in any endeavour until we have gone too far and then return to the ideal position. The plebs chorus correctly identified when I’d gone too far and listening proved no advantage despite doubling the spend and pile of shelves."

------

Wha-at?" exclaim plebs, stage left,"The old scribe’s gone too far this time!"

"Indeed your old scribe has gone too far with two Space Harmonisers, four steel cones, four Yamamoto MGB-1’s and four EAR vibration absorbing feet, as the difference is a negligible plus 3 and minus 1 between this and the condition tested in the table (pun alert).

This is neither cost effective nor elegant and therefore not worth the effort."


"The Yamamoto MGB-1 are the best isolation device I have tried with the Garrard 401/SME3012 series I."

Astronomers and Long Telephoto Lens Users have used Bicycle Inner Tubes modified to be filled with Kiln Dried Sand to absorb Micro Vibrations.
A inner Tube has been Cut to produce a Length of Rubber Tube,
One End is Sealed and the Tube is filled to approx' 75% full.
The Open end is then sealed.
The Sand Filled Tube is then placed on the Telescope or Lens to control resonance that is being detected a blurring of a focus.
I have produced these myself for a friends Manual Focus 800mm Telephoto Lens and they had reported that the View Finder has a improved sharpness.

This has in the past led me to ponder a method that might ?,
improve on the effectiveness of a Inflated Support for a Device.

Using a Inner Tube:
1,  inflating / deflating the inner tube to create a enlarged inner area.
2, remove the Valve from the Inner Tube, and attempt to fill the Inner Tube with Kiln Dried Sand. (A Small Funnel will be useful) 
3, When filled reinstate the removed Valve and inflate the Tube.
4, Experiment with Air Inflation Pressures.

This Method allows for a Combination of Management of resonances,
Air Suspension ( Airborne Vibrations) and
Sand ( Particulate Energy Dissipation )
There are methods already in place both commercially and DIY that address the use of a Suspension/Granular Isolation.

This method I am suggesting is a Simplified Method not requiring too much beyond a already commonly used method of using a Inner Tube.
  
The Inflation of the Inner tube would be potentially at its best
(Vibration/Resonance Control ) ?,
if it was inflated to the pressure to allow the Applied Weight
(Sub Plinth / Device ) , to have a Air Support, with the Kiln Dried Sand being Sandwiched, in contact with the Upper Inner Tube Wall.
How Much compression applied to the Sand can be determined through experiment. 

If a device is with a Uneven Weight Distribution,
Two Smaller Sized Inner Tubes could be used, to allow for the added inflation requirement for the Heavier end of the Sub Plinth and make levelling the Device easier. 

There is Room to experiment with the Air Pressures used,
a cheap Pressure Gauge can be used to record the Pressure that has produced a attenuation that is perceived as offering the desirable audible presentation.       
I believe the feet on the xtension 9 pro-ject turntable work in the same way, two opposing magnets. 
I have these in my system. They work fine. I have a set under my conditioner, one under my server and one under my pre. They don’t hurt nor can I say that they were a night and day difference. My system was very low noise to start with.
keep in mind they come in different heights and weight tolerance.