I’m glad you mentioned that, Todd, as one of the really big advantages of my "new style" cryo’d springs is their size, being only about 3/4" compressed in height. So they will Fit just about anywhere. You could even use them on submarines, one supposes, where space is a supreme issue. Hel-loo, US Navy! Are you listening? The other advantage of my mini springs that may not be obvious is that their lateral stability is greater than for larger springs, due to lower center of gravity when under load. Thus, they can be placed directly under components without all the trouble and expense and SPACE of having to place boards underneath the components as in the old days. My Promethean Base, for example, sorry no longer available, employed springs that were about 2 1/2" compressed height.
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Tom, while I can appreciate your persistence in this matter, apparently there CAN be isolation where there is MOTION as demonstrated by LIGO, the 4 km long interferometer experiment to detect gravity waves - the most critical portion of which is the vibration ISOLATION system - which BTW was successful last year in detecting gravity waves, you know, those teeny tiny physical waves left over from the Big Bang with amplitudes the size of atomic particles. HEL-LOO! So, apparently there CAN be ISOLATION where there is MOTION. I also submit as evidence all the testimony from users of vibration isolation devices on this thread. Have you NOT been paying attention? |
One point, the shallowness of the bottom cup doesn’t affect frequency of isolation as Barry theorizes. It affects effectiveness of isolation. Roller bearings aren’t really analogous to mass on spring devices. I.e, a very shallow concave surface provides better lateral isolation (ease of motion) but worse rotational isolation, since the component cannot rotate much when forced by rotational forces, it rotates by climbing the walls of the concave surface. Thus the shallowness is a trade off, it can't be too shallow or too concave. You could probably get really good horizontal isolation with flat bottoms and flat tops, you would just have to constrain the bearings from moving too much, and the component would have to be perfectly level and balanced. It could be done. So you got your roller bearings for the horizontal plane and 3 rotational directions and you got your springs for the vertical. Then all you have to worry about is how you mount the whole contraption on the floor and how to mount the thing on springs. Ah, the art of isolation. |
Todd, what Barry Diament (long-term roller bearing proponent, and audiophile recording engineer) suggests is a roller bearing comprised of only one cup (the bowl facing upward, of course), the ball bearing sitting in it, and a hard ceramic floor tile put on the bottom of the component at the locations where the three ball bearings touch, the ball bearing then rolling smoothly against the tile. The original Symposium Roller Block itself had only a single cup, with another of their products recommended for the bottom of the component. The Roller Block Jr. (the $199/3 model nutty mentioned) is a pair of cups, the bowl in each facing each other, the ball bearing between them and riding in both. Barry theorizes that a single bowl provides isolation to a lower frequency; a ball bearing on a flat bottom surface would provide even more lateral (horizontal) isolation, but would then be free to roll right off your rack! The shallower the bowl (the larger it’s diameter), the lower the roller bearing’s resonant frequency. The Ingress $85 model and the Symposium Roller Blocks have bowls of about the same diameter; the new Ingress model has a bowl machined to Barry’s suggested larger diameter (Ingress’ is 1-1/2"), and is made from Alcoa 7075 aluminum, harder than the 6061 of the original, and polished to a smoother finish, for lower rolling resistance. The new model is also a single bowl design, not a double like the original. But like I said, there is nothing to stop you from turning one set of double-bowl bearings into two sets---just buy three more ball bearings and some ceramic tiles! There are also different grades of ball bearings themselves---Symposium sells them at a couple of price points, but they are also available from ball bearing vendors on the 'net. |
Actually the high carbon chrome steel bearings require the extremely hard surface of the top thingies that are provided to perform properly. The underneath surface of the component doesn’t quite cut it, it’s not hard enough and tends to flex. The other problem is without the two upper pieces the component will tend to roll. All three bearings need their top constraining pieces. This constraint forces the bearings to move very slightly up the concave inside of the bottom cup when forced by external uh, forces. All three bearings must be free to move freely in their bottom cups. Otherwise you lose all the isolation. The component must obviously be leveled precisely on the roller bearings and the roller bearing just be in located precisely such that mass is uniformly distributed. |
Roller bearings can be had from Ingress Engineering in Canada for as little as $85 for a set of three. If you use only one of the two bearing cups at each location instead of two (look at them to understand what that means!), with the ball bearing directly in contact with the bottom of the component being isolated instead of the top cup, buy three more ball bearings and that set of three becomes two sets of three. Much cheaper than some other high end isolators, and not much more than Sorbothane half-spheres. |
I second the roller bearing idea. The concave shape of the base is a very shallow angle so there is some isolation horizontally I think. They also are good in the twist and the other two rotational directions due to the concave shape of the roller bearing bases. Can’t recall if I mentioned it already but Super Balls on Snaple bottle caps is a faux roller bearings for those DIYers out there. |
Ya, and since springs isolate vertically very well, but laterally not-so-well, a set of roller bearing somewhere. I prefer them directly under the component where possible. So, the component, the roller bearings, the maple platform, the springs. Roller bearings provide no lateral isolation, acting as a coupler in that plane, transferring energy just as do cones, if you believe in that sort of thing ;-). |
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Jitter, I just explained it. I don’t like having to repeat myself so I won’t. By the way if you’re trying to convince me that you’re a little thick you’re doing an excellent job. Dylan used to answer when asked what if someone rushed the stage, just kick him in the head. He'll get the idea. You, on the other hand, keep coming backing for more. I don't mind if you don't. 😬 |
Geoff, I know you will correct me, but your argument is based on the fact that in the process of pulling the wire through the die the crystals get damaged, that is, the damage forms a directional bias. The passage of protons and electrons are impacted as they flow, if AC, in both directions. So if the AC current flows in both directions, how can it matter which direction of the bias wire (fuse) you place it? |
George, the part of the AC that goes in the direction of the speakers is obviously the only part that matters. Who cares about the part that travels in the direction toward the power company? That’s why fuses in AC circuits are directional. You don’t have a leg to stand on. You can try holding your breath until you turn blue, mox nix to me. |
Yes "True Blue" http://www.urbandictionary.com/define.php?term=true+blue+aussie Not interested in arguing on any level, with someone who believes an AC mains fuse is directional. Cheers George |
Geoffkait: "nothing can provide 100% isolation at 5Hz" Georgehifi: "Did I say total Isolation, NO!" Geoffkait: "So, what did you mean to say, 1% isolation? 10% isolation? That’s why it was misleading when you stated isolation down to 5 Hz. Capish?" Georgehifi: "And neither can anything else, there is airborne feed back from speakers that also comes into it short of putting the equipment in another room this is the hardest one to eliminate, also if you have tubes that are micro-phonic, then your up a creek without a paddle." Geoffkait: "Uh, one said anything else can provide 100% isolation at 5 Hz. Everybody knows almost all REAL isolation devices are low pass filters. Putting the equipment in another room is not going to be 100% effective since the entire building is shaking. Hel-loo! Furthermore, airborne vibration from most speakers doesn’t go down below 25 Hz, anyway, so you can forget about it. Besides all tubes are microphonic, even the ones marketed as "low microphonic." Hel-loo!" |
absurd since nothing can provide 100% isolation at 5HzDid I say total Isolation, NO! And neither can anything else, there is airborne feed back from speakers that also comes into it short of putting the equipment in another room this is the hardest one to eliminate, also if you have tubes that are micro-phonic, then your up a creek without a paddle. Cheers George |
Innocent question: if Sorbothane is really so great an isolator why don’t the big boys at LIGO use Sorbothane? Obviously something’s wrong somewhere. Now, it’s possible that in some density Sorbothane might, emphasis on the word "might", be used as a constrained layer damper. But there are better materials for that application. I suspect Sorbothane is best relegated to running shoes as it apparently is a decent shock absorber. Which as I pointed out before actually makes it a poor isolator. Besides Sorbothane sounds well, funky. It’s not open and natural sounding like competent isolation devices. As LIGO found out after 20 years of isolation system development, there’s really no substitute for good old mass-on-spring techniques. Besides mass on spring devices routinely get down to 3 Hz performance and can be as low as below 1 Hz. Accept no substitutes. Finally the suggestion that Sorbothane can isolate down to 5 Hz is patently absurd since nothing can provide 100% isolation at 5Hz. Isolation is always a low pass filter. Of Sorbothane could isolate to 5 Hz LIGO would be using it. |
There are different densities of Sorbothane, the soft one will get down to 5hz but one needs to wrap it in Gladwrap before putting it under heavy equipment, otherwise it will spread over time. I measured and listened to both densities with a rare Shure frequency response test record under a non suspended turntable and the soft 10hz they sell on ebay, measured and sounded like it isolated just as good as the super-soft one. I say go the one on the eBay link I posted. Cheers George |
Don’t go buying expensive audiofool stuff. Just get some Sorbothane feet or pads on ebay, pick your size. http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1311.R7.TR12.TRC2.A0.H1.Xsorb.TRS0&_nkw=sorbothane+feet&_sacat=0 Cheers George |
schubert, I find the by using the Notepad 2 effective. Especially when used in combination with my Studiotech audio rack and Nordost Pulsar Points Isolation Feet. My audio racks shelving is spiked as well. I place mine over the transport of the player. Thats where I personally believe it is most beneficial. Here's why... vibration. As we know, a CD spins at varying speeds. Additionally, it begins on the inside groove. On the inside groove of the CD spins at 200 rpm's and gets to as fast as 500 rpm's as the laser beam approaches the outer edge. In the end is it a "Miracle Pillow"? No. However, the reduction of vibrations is always a good thing for mechanical reliability of any mechanical device. It is also well know that reduction of vibrations has an audible effect on TT's and tubes.... They do wear out over time as the manufacturer states. I keep purchasing them. I've owned the 1- original Notepad. 1- original Notepad that prematurely failed. It deflated in less than a year.. Gutwire sent me a new replacement for free. And I'm on my 2nd- Notepad 2. None of mine have ever left any markings on my equipment. Though I've only used them on digital gear. N |
Gutwire Notepad 2. "... Specifications:
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I use both of these products for my amps, cd players, and turntables inside my bookcases, as well as underneath my speakers: Neoprene and cork pads https://www.globalindustrial.com/p/fasteners/vibration-isolators/pads/neoprene-cork-pad-4-x-4-x-1 Natural Rubber pads https://www.globalindustrial.com/p/fasteners/vibration-isolators/pads/easy-cut-waffle-pad-natural-ru... Rich |
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I have a pair of 4 inch' thick maple boards made by Timbernation. They excellent . I then asked for a custom isolation stand for my pre amp. He disappeared for several months, so I can guardedly recommend him. PS I got my deposit money back. I also have immense brass footers by Edensound. He is reasonable and reliable. I think he has a presence on Yahoo. I put them on my pre which is tubed and occasionally microphic while playing , no tapping. It uses 6SN7s some of the oldest and most precious can be noisy. The footers damped the pre well but tripled its weight . His prices were more than fair. He even drilled the correct size screws for receptacles on my pre. |
This is kind of a tough question as it depends upon your cabinet and its' construction. Though it may be considered heresy to some on this forum, I don't worry too much about it. Some of these tweeks can get a bit anal, as well as costly. I mostly use Herbie's isolation for my equipment. Though I'm sure you can also use an isolation platform, as well. Another thread has been focused on Townshend Audio isolation products. The OP swears by them, and I have to admit, I am more than a bit interested in trying them. B |
