Equipment isolation and vibration damping.

[4est]

I think the cup and bearing materials are less about ringing, and more about surface hardness:rolling friction, stick-slip, deformation ect. Consider Barry's experience as mentioned elsewhere in this forum. He noted changes with chrome vs carbide balls and different grades of aluminum for the cups. All while things were floating on lightly inflated tubes. There just doesn't seem like enough difference between the materials in situ to account for it. The jerking of stick-slip seems like a prime candidate, but it is a guess without testing.

 

These are close to what Barry recommends (just use one per support instead of two) but made from coated steel instead of aluminum:http://www.firstimpressionmusic.com/product_p/model%20305-3.htm

Certainly because even with less than ideal materials, the process of isolation is occurring to some extent. Perfect for initial experiments compared to no isolation at all.

 

 

 

That's very cool, Daudio. As ringing, is acrylic a good material? I gather we'd need hardest and smoothest, but also something which does not ring too much, or if it does ring, then we need to dampen that by encasing it within some other material.

 

 

 

Very encouraging. How large can you make these?

[4est]

Because the rolling friction is too high using teflon.

How about polished steel, as in those camping mirrors that John S. recommended ?

 

Aluminium doesn't polish well, probably the softness, but anodizing does create a very nice surface on alu, but not quite as good as a polished hard metal, IMHO.

 

There is something about a Teflon coating that just doesn't sit right with me for this application, but I can't put my finger on a rational explanation.

[4est]

I imagine the balls and cups are larger for a building sized set, as are the forces. The compression of the teflon coating would matter much less.

Yes, but if we want freer oscillation, doesn't friction damp it? So I was looking for a way to reduce that, but still keep the hardness aspect.

 

After reading on industrial seismic isolations of the ball and cup type, I saw at least one manufacturer mentioning Teflon.

[4est]

If one was to use glass, maybe they should consider having it tempered. The change in surface tension might be of benefit.

Hi Sam,

 

Pulling your leg? Do you mean regarding the name? Or something else?

No joking intended. Sorry if I wasn't clear. (The name is explained in one of the blog entries.)

 

Not sure why the contact materials would need to be different. How would the ball "know"?

As it happens, I'm using different materials since the top is either dead marble tile (smooth side against the ball) or the chassis itself (if smooth enough).

My experience as an amateur astronomer and telescope enthusiast has shown me that glass is a lot more flexible than one might think. I would not use it for audio purposes (unless I was designing transparent bells ;-).

 

Best regards,

Barry

Soundkeeper Recordings

http://www.soundkeeperrecordings.wordpress.com

Barry Diament Audio

[4est]

These are likely too heavy duty, the smallest is rated at 100# per unit. To achieve that the wall thickness of the pod will be great enough to cause issues.

 

No one has mentioned it as of yet, but one could use Sodium Hexaflouride in Barry's inner tube concept. It is more compress-able whereby allowing a higher tube pressure or a lower resonant frequency than compressed atmosphere.

These look quite cool, and the air inside could be indeed like what Townshend uses in his pods or as in some tables which use an air diaphragm with a valve in it.

[4est]

Are you saying that your tonearm moves independently from the platter?

When you hear 'new' things in well-known tracks, you know you're on the right track of progress. These are quite good results with your turntable.

 

Mine already has spring isolation, one for the platter, one for the tonearm base, so I'm not sure it will benefit.

[4est]

OK then, it wouldn't work properly otherwise. Just wondering...

I thought so, but on checking, no it's not separate isolation platforms, it is a single one although it appears from the upper surface to be two different areas.

 

The platform is, however, a spring-based isolated one.

 

It's a Technics SL-1800 direct-drive, quite similar to the original SL-1200 but with less features.

[4est]

How are you using them? Barry suggested an equilateral triangle, which makes sense to me. How does one do that with an 11x17 board?

I was playing with different types of bamboo boards, from cheapest to expensive Japanese imports. Most expensive from them are quite thick, and they add to sound characteristics rather than isolate. The idea is everything what we use to support components needs to be neutral, is bamboo neutral?

 

One good thing, if you decide to put that pricey Japanese board out of audio your wife will be most than happy to see it in the kitchen.

[4est]

If one is having trouble finding stone tile the correct size, there are always stone counter top fabricators. Marble is quite soft as been noted, and it often has a lot of filler. Granite might make a good alternative. It will polish smoother, and be less likely to have hairline fractures or filler.

The 20x20 reference was for for spkrs I believe? 18x18 is a size that will accommodate most components and fit on a rack. I maintained the same ratio for tiles and plywood.

 

You want to keep the size square on whatever size used to avoid imbalance/lopsided components.

 

You prob won't find the tile needed at the Home Depot's. From my experience a tile shop of some sort are your best odds. If you order online there are an abundance of choices, but you won't know what you get until its delivered. Also you can't "tap" them to make sure they're not too ringy

 

Some of the shops that perform tile installs have a huge "scrap" pile in the back of their shop and will let you take whatever you want for free - just a thought.

 

I wouldn't use anything less than .5" thick tile, mainly for strength / density characteristics.

 

Sent from CA app

[4est]

I think this is incorrect. It is very likely that the crush force of many tubing types would exceed what is exerted. That 75# amp only requires a few psi.

I can't see you finding a hose that would be small and strong enough to pass over, or under, the inner tube ring, without some kind of distortion and interference with its proper functioning. Therefore it has to go out the center, either through the top, or bottom.

 

[ATTACH=CONFIG]19861[/ATTACH]

[4est]

I think that most tubing used to extend the valve would be plenty strong and not compress under the applied force. It would be east to extend. Maybe I misunderstood you Dave?

Forrest,

 

What is incorrect ? I'm not following you at all.

[4est]

Gosh, I hope I didn't seem bossy Dave- my apologies. I dunno if I would be too concerned with the fill tube crossing the bladder as long as it was not bottoming out. I feel more concerned with the idea of twisting the tube in order to expose the valve. That would seem to create a built in spring tension.

If it were me, I think I would take the valve out of the Schrader valve body and glue in a 3mm tube long enough to extend to the rear. There I would have a needle valve and a low pressure air gauge (15 psi?). All of that should be available at Menards btw, or Mcmaster Carr of course. If one really wanted to trick it out, once the known pressure is determined, the tubes could be evacuated, and filled with SF6 which is 5-10x more compressible than atmosphere, whereby lowering the resonant freq.

Yeah, I'm not worring about the extension hose. I'm worried about the inner tube distorting from a largish diameter, stiff tube crossing it and disrupting its ability to flex and provide smooth support. You Ok with that, Forrest ?

[4est]

No worries!

 

Well, the Schrader valve body is about 6mm, and the bladder tube needs to be inflated beyond that, let's say 8mm. 8mm-3mm tubing-2mm tube wall=3mm clearance. IDK, seems like it ought to be OK. If you were really worried about the discontinuity, you could throw a couple more equidistant around the bladder...

Forrest,

 

Sorry, I did not mean anything by the "Ok with that" thing. It was poorly expressed, and not meant to have any negative connotations. My apologies.

 

 

 

 

I agree that would be a better way to go, but the original questioner seemed to want an easier solution, and that's why I was perusing that avenue.

 

I too would like a flexible fill tube to easily route out of the inner, inner tube ( ). I still have strong reservations about anything that distorts the shape of the rubber torus as it does its job of supporting the load and absorbing small vertical movements (vibration). Including turning them inside-out, which I think would change the stress's in the rubber walls. (probably not enough to negate the value of an easy fill access in tough situations, through).

[4est]

You have company!

P.S I know that YashN probably has me on 'Ignore', so this is for everyone else

[4est]

I noticed this too, and felt it was a prudent move.

[ATTACH=CONFIG]19883[/ATTACH]

 

Here is a better pic. It's rollers > tile > plywood (which the spkrs rest on)

[ATTACH=CONFIG]19882[/ATTACH]

 

The little "blocks" are just there for a some reassurance They're not touching the tile and I actually removed them and filled the large voids (of the triangle) with large spare plywood cuts. In reality, one would have to give a pretty firm shove or bump to the spkrs before choice words would be said

[4est]

I am sure they could cut it into an octagon which would likely be close enough for this purpose.

I really like those Ingress bowls. They are exactly what I am looking for to replace the ceramic incense burners(which seem to work quite well for the moment). I like the fact that the incense burners hold my GT 2000 aloft from the granite block. It allows me to move the tuning weight around beneath the turntable. When I get the Ingress bowls, and I will be getting them, I'm going to get a local machinist to lathe three supporting columns to hold the three Ingress bowls. I would expect, given the wonderful results I am getting with the stop-gap ceramic incense burners to be multiplied when I put the Ingress bowls into this set-up. As I stated at AudioKarma, the set-up I have at the moment(which is exactly as you see it in those photos) works extremely well but it still remains a work in progress.

 

Because unlike the inner tube method the ring of Clearaudio Magix is comprised of 21 discrete elements, one has to strictly ensure that the load seen by each of the 21 Magix is shared evenly. Hence with this type of implementation the stress I've placed upon getting the Center Of Gravity correctly positioned. Doing that and tuning the load utterly remain the key to getting the results I have obtained. I surmise that if I could get a granite block cut to be circular, that would be even more advantageous. The local fellows who supplied and cut the granite for me can't cut circles. I should canvas the other stonemasons in my region to see if there are any who can.

 

As enthused as I am by the results I have obtained so far, I suspect that I've possibly only gotten a hint of what my method will yield down the track. That's a nice thing to hold onto.

[4est]

+1

Capacitors are often microphonic as well!

 

Crystals are certainly sensitive to vibrations -- it would be great to see the effects on phase noise plots.