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Posted by Romy the Cat on
11-26-2008
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fiogf49gjkf0d Ok, it is bogus but no more bogus than anything else in “Ultimate Turntable” thread. Still, I like the notion, even though I have no idea if it might have any sonic consequences. I do not see the concept was used in turntable; perhaps the people who make turntables would give some thinking to this idea.
Among many professions I had in my youth one of them was a locomotive engineer. So, when I was driving trains I remember that under the same conditions to stop a 6.000 tones train with coal took much shorter distance then 5.000 tones train with oil. It is obvious that the inertia of oil displacement propelled the train forward creating extra moment.
Why do not use the same idea in a TT’s platter.
Pretend that we have a good mass platter and this platter in addition it it’s mass has a large circular chamber near the outside skirt. The chamber or the channel is 50% filled with some kind of heavy liquid. When the platter start to spin and reach it’s stable cruse speed then in a few moment the liquid synchronies with platter, becoming dynamically in uni-speed with platter. Now when the platter has mine fluctuation in speed then the liquid try to maintain it’s gyroscope moment and by tension with the chamber’s wall it would damp the speed fluctuations. It sounds very reasonable to me.
This idea has even some very good marketing possibility as the outer wall of the chamber might be made transparent and a user will be actually seeing the liquid. Now, pit on the wall of the chamber some verticals screen and insert into the liquid some floating markings and you have a perfect natural indicator of platter’s stability.
I can see the Stereophile advertises the tunable with “Heavy Water” platters…. Sounds catchy. The Cat
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Posted by serenechaos on
11-27-2008
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fiogf49gjkf0d How strange...
I was thinking about this, and discussing it during lunch @ the lab a couple days ago...
Got there from a totaly different direction though, was thinking about harmonic vibration dampers used on crankshafts, (usually iron, rubber ring, another iron ring), and how better ones use a viscous fluid instead of the rubber.
We went crazy hi-tech (of course, it's Los Alamos), and were pipe-dreaming ferro-fluid or something that could be used to actually change viscosity, as needed to make subtle damping changes, for subtle speed changes.
Viscous ferro-fluid could be used for magnet drive for turn table...
No, that would cause interference with cartridge...
Then realized that was too carried away, but something like glycerin, in a ring you could see might be nice.
Then back to playing with plutonium & platinium...
Now I'm gonna be imagining Cat driving Train all day...
Robert
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Posted by drdna on
11-27-2008
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fiogf49gjkf0d Easier to make might be a device like a record clamp you can attach to an existing turntable platter. It should be easy to do the experiment by trying a weight on the turntable platter:
1. a solid weight
2. an equal weight container of viscous liquid (you can try different liquids, maybe even Single Malt Scotch)
Then just listen to compare if there is a difference. I will be interested to hear what results everyone has.
Adrian
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Posted by Romy the Cat on
11-27-2008
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fiogf49gjkf0d  serenechaos wrote: | | Viscous ferro-fluid could be used for magnet drive for turn table... |
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Actually I like this idea a LOT. I do not know how about the ferrofluids but the idea of viscous drive sound very attractive… Pretend we have a stationary fluid dispenser that tosses a steam of fluid on the wall (perhaps internal) of the platter. Visualize a fire hose with termination of some kind of jet proportion accelerator. So, the stabilized flow of the fluid hits the wall of the rotational platter at angle of let say 30 degree. By the tension between the jet of fluid and the wall (the wall might have some granularity of vertical texture) the spinning moment is created. The fluid is collected then, return to the pump and injected back to the jet dispenser. We could read the rotations speed of the platter and change the voltage on the pump, introducing the self-regulating servo stabilizing. Funny but the fluid by the nature of given propulsion will serve as a perfect decupling mechanism of this servo stabilizing loop. Do you want to do kinky? Well, let load this type of fluid drive with oil and then as we settle at cruse speed let to heat up the oil, reducing its viscosity…
The Cat
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Posted by Romy the Cat on
11-27-2008
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fiogf49gjkf0d | drdna wrote: | | Easier to make might be a device like a record clamp you can attach to an existing turntable platter. It should be easy to do the experiment by trying a weight on the turntable platter: 1. a solid weight 2. an equal weight container of viscous liquid (you can try different liquids, maybe even Single Malt Scotch) Then just listen to compare if there is a difference. I will be interested to hear what results everyone has. |
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Yes, it might be cool but it would take time to stabilize after you put it on a record on the platter. As the experiment it would be perfect, even better to implement this type of centrifuge stabilization inside of the external record clamp (that sits outside of record) – trios clamps might be used within some turntables. The outside clamp has higher speed and it will do more effective viscous stabilization. The only problem is that in this case is needs to be some kind objective control that liquid speed is synchronized with clamp’s speed. In case of platter it would not an issue as liquid speed will not be affected (or affect very minorly) by the change of records.
The Cat
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Posted by guy sergeant on
11-27-2008
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fiogf49gjkf0d I never did see or hear one of these but I'd be interested to know how constant they were able to make it.
"...this was a curious turntable with a viscous clutch-like transmission: a layer of water and glycerine between platter and a fanned motor transmits the torque to the upper platter...."
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Posted by deemon on
11-27-2008
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fiogf49gjkf0d +++++++Pretend that we have a good mass platter and this platter in addition it it’s mass has a large circular chamber near the outside skirt. The chamber or the channel is 50% filled with some kind of heavy liquid.++++++++
Good idea , Roma , but what for me , I'd fill 100% of the chamber with this liquid .... it will behave in more stable way .
Dima
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Posted by Lbjefferies7 on
11-27-2008
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fiogf49gjkf0d Great minds think along the same lines. A couple of days ago, I was thinking of a fluid driven turntable platter. What I was thinking was to have a plinth with spiral grooves cut into it. The platter (perhaps with radial grooves) would float on a consistant flow of oil. The oil could be purely gravity fed, thereby completely isolating the 'table from pump noise. Speed could be varied by the amount of oil in the accumulator tank. Sure, it is completely impractical and may be a bigger disaster than the time I tried to steal Imi Litchtenfeld's wallet, but their may be something to it.
LBJ
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Posted by Romy the Cat on
11-27-2008
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fiogf49gjkf0d LBJ,
I do not think that the idea of Water Tower is good as we would need to change the TT speed. Also, I think the verso is necessary for us as liquid has different viscosity with temperature and we need somehow to compensate it. What I found inspiring it your proposal is the idea to combine proportion with suspension. Let me to merge what you proposed and what I proposed in the “More about the fluid drive” post. Her we have something quite unique…
Ok, let reveres what I proposed in the “More about the fluid drive” post. We have no stationary jet dispensers that shot angled liquid to platter but we have 2 or more stationary angled jet dispensers that shot off the platter. Now the platter acts an independent entry the has no external propulsion and spanning only by the thrust generated by discharging liquid from the platter’s nozzles. The platter is not only tossing the liquid but also is sitting on the liquid. Let for the sake of being crazy proposed that it is a non-magnetic steel platter and liquid is mercury. Steel is lighter then mercury, so we have a perfect self-prolusion, self -centering and self balancing platter.
Actually this idea sounds so sexy that even to fantasize about it I feel kind or …erotic. Of cause I do not do sonic claims and it is very possible that after the “Mercury Fountain Turntable” hit hi-fi stores and 3235 people would die from mercurialism it will be learned that the idea of liquid propulsion is worthless from sonic perspective. Hmmmm! Perhaps it is not the turntable innovation but the notion of killed 3235 moron-audiophiles is something that makes me horny? Go figure…. Anyhow, I need to run to feed my Cat with her Thanksgivings turkey…
The Cat
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Posted by Lbjefferies7 on
11-27-2008
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fiogf49gjkf0d A turntable that is attractive to Morons that just so happens to kill them off...HA! Reminds me of the tantilizing glow of a bug zapper. ZZZAP! There goes another one.
It seems that a liquid driven/suspended platter would have to opperate off of two separate systems, one with a fixed pressure to suspend, and one with adjustable jets to facilitate speed adjustment. That is unless a sophisticated nozzle could be made that would increase pressure without increasing volume output. I'll have to research more.
I do have an interest turntables now as I am looking to upgrade my sources (digital too). It is doubtful that I will go in such an insane direction...It would probably be much more valuable to dredge up an old RX-5000 or 8000. What's the deal with Micro Seiki, anyway? Are they still in business? I haven't found a website.
My Kindest regards to you and your Koshka on Thanksgiving!
LBJ
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Posted by serenechaos on
11-27-2008
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fiogf49gjkf0d Liquid drive/suspension could work with variable angle jets as well.
Still more complicated than it's worth, and too difficult to get to run smoother than existing (better sounding).
Probably marketable though!
So how about a "special" MM (moron mercury) jet?
That would rotate and engage for "special behavior"...
Too much...
Hoping you and Koshka had a great, Mercury-free Turkey day!
Robert
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Posted by guy sergeant on
11-28-2008
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fiogf49gjkf0d Visiting the Paris Hifi Show a couple of times in the late 80's I saw a turntable with a heavy platter floating in a bath of exposed!!! mercury. The people running the demo did not look well (grey pallor, lacking hair) and looked even worse the second year. I didn't see them again after that!
http://www.bonavolta.ch/hobby/en/audio/td_hg.htm
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Posted by drdna on
11-29-2008
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fiogf49gjkf0d | Romy the Cat wrote: | | What however is very practicable is some kind of sealed TT mat of 2-3 cm tall, fully filed with mercury. It would be 10kG of inertial mass – it might work… The question is how? |
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Ah, this is a GOOD idea! Wood would be the easiest material with which to make a prototype, and it can be readily turned on the lathe that is used to make horn loudspeakers. I bet the same craftsmen can do it for you. The inner chamber can be sealed and filled with mercury from amalgam. Or perhaps a plaster model can be made? I am sure this is how Jessie would do it.
I still think that a record clamp idea is the easiest way to start to experiment to see the sound. My concern is that the mercury may cause some ringing in the platter.
Adrian
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Posted by N-set on
01-22-2017
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For some reason I've remembered this old idea of Romy and decided to check it
from the physics point of view. Unfortunately it seems it will not work:
the momet of intertia of a fluid in a vessel is with a resonable accuracy zero with
respect to the fluids center of mass. So rotating the fluid, one wouldnt feel much its presence.
This is in contrast to moving its center of mass (like in Romy's example of a train with oil), when
the intertia will manifest itself. Here is a nice explanation with a good example
(the 1st answer):
https://www.researchgate.net/post/Can_we_use_the_term_rotational_inertia_for_the_fluids
Cheers,
Jarek
| Romy the Cat wrote: | | fiogf49gjkf0d Ok, it is bogus but no more bogus than anything else in “Ultimate Turntable” thread. Still, I like the notion, even though I have no idea if it might have any sonic consequences. I do not see the concept was used in turntable; perhaps the people who make turntables would give some thinking to this idea. Among many professions I had in my youth one of them was a locomotive engineer. So, when I was driving trains I remember that under the same conditions to stop a 6.000 tones train with coal took much shorter distance then 5.000 tones train with oil. It is obvious that the inertia of oil displacement propelled the train forward creating extra moment. Why do not use the same idea in a TT’s platter. Pretend that we have a good mass platter and this platter in addition it it’s mass has a large circular chamber near the outside skirt. The chamber or the channel is 50% filled with some kind of heavy liquid. When the platter start to spin and reach it’s stable cruse speed then in a few moment the liquid synchronies with platter, becoming dynamically in uni-speed with platter. Now when the platter has mine fluctuation in speed then the liquid try to maintain it’s gyroscope moment and by tension with the chamber’s wall it would damp the speed fluctuations. It sounds very reasonable to me. This idea has even some very good marketing possibility as the outer wall of the chamber might be made transparent and a user will be actually seeing the liquid. Now, pit on the wall of the chamber some verticals screen and insert into the liquid some floating markings and you have a perfect natural indicator of platter’s stability. I can see the Stereophile advertises the tunable with “Heavy Water” platters…. Sounds catchy. The Cat |
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Posted by Crazy Dave on
09-21-2022
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I was scanning around the net for interesting info and found this thread. Not only do I think this idea is viable, I own a version of this table. It is the J.A. Michell Hydraulic reference (also sold under the Transcriber brand name). It has been around in one form or another since the 60's. Beneath the heavily weighted platter spins a vat of damping fluid. there is a rod that drags in the fluid, adjustable from the side, that you change the speed with. The palter and the table are very dead. You can tap on the table while its playing and it won't mistrack, even with a high compliance cartridge. The arm is reputed to be over complicated fragile junk. I don't know because mine came with a Grace 707. Nice, as low mass vintage arms go, but I changed it for something with more mass. Some people modify it with a modern style flat platter, but I left mine the way it was, because I love the look. The motor is not low powered, like the AR/Linn. It has a good amount of torque, even through the damping fluid. It is a belt drive. Although I have never been able to compare it with any of the super high end tables, the sound is very good to my ears, especially considering the age of the design. Mitchel still supports this table. I bought some parts a few years ago.
Dave
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