Hergest Posted November 11, 2013 Share Posted November 11, 2013 What an unbelievably stupid idea! What an unbelievably stupid idea! A squash "ball" is filled with air; once you cut it in half ... the air disappears! A good isolation platform is a heavy slab with some "springs" underneath - these "springs" can be "real springs" or an air bladder. Squash balls - or a semi-inflated kid's-bike inner tyre - provide the air. If some squash balls went flat, I suggest they were either old and degraded ... or they had too much weight pressing on them; 3-5kgs per ball is the ideal, AIUI. Regards, Andy Stupid yourself, adding a ridiculous smiley doesn't make you any less of a prat. Give it a rest mate. Link to comment Share on other sites More sharing options...
DrMeeck Posted November 14, 2013 Share Posted November 14, 2013 Just to skip back a bit. People are talking about using rare earth magnets to produce a "levitating" platform and I've had a few ideas on the same subject. But,and here my high school physics lets me down, does anybody know what sort of effect the magnetic field would have on the turntable electronics? Would the field induce unwanted currents? And therefore exacerbate any problems already there? Link to comment Share on other sites More sharing options...
Chill3 Posted November 14, 2013 Share Posted November 14, 2013 Just to skip back a bit. People are talking about using rare earth magnets to produce a "levitating" platform and I've had a few ideas on the same subject. But,and here my high school physics lets me down, does anybody know what sort of effect the magnetic field would have on the turntable electronics? Would the field induce unwanted currents? And therefore exacerbate any problems already there? All the devices am aware of are designed to "contain" the magnetic field. If that were no the case it would be very problematic , as cartridges as very sensitive to magnetic fields Link to comment Share on other sites More sharing options...
Hergest Posted November 14, 2013 Share Posted November 14, 2013 Has anybody used anything like this from Acoustic Revive? It seems one of the more elegant ways of doing things. http://www.acoustic-revive.com/english/underboard/raf-48h.html Link to comment Share on other sites More sharing options...
3G_ Posted November 14, 2013 Share Posted November 14, 2013 (edited) Has anybody used anything like this from Acoustic Revive? It seems one of the more elegant ways of doing things. http://www.acoustic-revive.com/english/underboard/raf-48h.html I have not tried it but I like how the Hickory gives an Organic sound Edited November 14, 2013 by 3G_ Link to comment Share on other sites More sharing options...
Once Analog Posted November 14, 2013 Author Share Posted November 14, 2013 Has anybody used anything like this from Acoustic Revive? It seems one of the more elegant ways of doing things. http://www.acoustic-revive.com/english/underboard/raf-48h.html In my opinion, it's how a turntable platform should look, beautiful! Vince 1 Link to comment Share on other sites More sharing options...
Hergest Posted November 14, 2013 Share Posted November 14, 2013 I have not tried it but I like how the Hickory gives an Organic sound Yes, that made me smile. Saying that though, my unsuspended SME Model 10 is profoundly affected by what material it sits on so if it was on hickory rather than say treated pine i might well pick 'organic' as the epithet to use for describing the sonics. Link to comment Share on other sites More sharing options...
DrMeeck Posted November 15, 2013 Share Posted November 15, 2013 A few pieces of MDF and use bubble wrap instead of an air bladder and Bob's yer uncle! Plus lots of black paint for the piano gloss look... 1 Link to comment Share on other sites More sharing options...
metal beat Posted November 15, 2013 Share Posted November 15, 2013 Has anybody used anything like this from Acoustic Revive? It seems one of the more elegant ways of doing things. http://www.acoustic-revive.com/english/underboard/raf-48h.html You can buy a used one from Melb for $579. http://www.ebay.com.au/itm/Acoustic-Revive-RAF-48-Air-Floating-Suspension-Board-/301015555760?pt=LH_DefaultDomain_15&hash=item4615ecdeb0 Link to comment Share on other sites More sharing options...
frankn Posted November 15, 2013 Share Posted November 15, 2013 In my opinion, it's how a turntable platform should look, beautiful! Vince Isn't this a clone of the original Townsend seismic sink isolation platform? Using slightly different materials Link to comment Share on other sites More sharing options...
Hergest Posted November 15, 2013 Share Posted November 15, 2013 You can buy a used one from Melb for $579. http://www.ebay.com.au/itm/Acoustic-Revive-RAF-48-Air-Floating-Suspension-Board-/301015555760?pt=LH_DefaultDomain_15&hash=item4615ecdeb0 I'd be happy to take a punt for a couple of hundred dollars but for $600 delivered it's a no goer. Link to comment Share on other sites More sharing options...
samman Posted December 20, 2013 Share Posted December 20, 2013 I received a set of isolation springs from Vince ( Once Analog) yesterday. He made three sets, one for myself the second for an OA turntable customer in Sydney, while hanging on to the last set for himself. After having a bit of a play with them last night, all I can say is " what a difference". The sound stage has grown significantly in height, width and depth. The separation of instruments has increased, the base has improved with the overall result exceeding my somewhat sceptical, preconceived opinion of them actually making any difference. Go figure, these things actually work.......... 1 Link to comment Share on other sites More sharing options...
andyr Posted December 20, 2013 Share Posted December 20, 2013 Now you understand the "good thing" about a sprung TT, Sam. But what material is the slab above the springs and below the OA plinth? Regards, Andy Link to comment Share on other sites More sharing options...
MrRogers Posted December 20, 2013 Share Posted December 20, 2013 Now you understand the "good thing" about a sprung TT, Sam. But what material is the slab above the springs and below the OA plinth? Regards, Andy Now you can call it a OA12. 20mm green marble. Link to comment Share on other sites More sharing options...
samman Posted December 20, 2013 Share Posted December 20, 2013 Hi Andy The tt is sitting on a Granite slab.. Cheers Sam Link to comment Share on other sites More sharing options...
andyr Posted December 20, 2013 Share Posted December 20, 2013 Aah, granite. thanks, Sam. Andy Link to comment Share on other sites More sharing options...
metal beat Posted December 20, 2013 Share Posted December 20, 2013 Aah, granite. thanks, Sam. Andy looks like Vince copied my copied design after all 1 Link to comment Share on other sites More sharing options...
Chill3 Posted December 20, 2013 Share Posted December 20, 2013 looks like Vince copied my copied design after all Looks like a direct copy , should ask for royalties 2 Link to comment Share on other sites More sharing options...
andyr Posted December 20, 2013 Share Posted December 20, 2013 Nah, mate - copies of copies of copies ... get nothing! Andy Link to comment Share on other sites More sharing options...
kana Posted December 20, 2013 Share Posted December 20, 2013 I received a set of isolation springs from Vince ( Once Analog) yesterday. He made three sets, one for myself the second for an OA turntable customer in Sydney, while hanging on to the last set for himself. After having a bit of a play with them last night, all I can say is " what a difference". The sound stage has grown significantly in height, width and depth. The separation of instruments has increased, the base has improved with the overall result exceeding my somewhat sceptical, preconceived opinion of them actually making any difference. Go figure, these things actually work.......... 20131219_195047.jpg 20131219_195116.jpg Nice looking springs Sam, Great to hear they make a difference, it looks like the tt is ready for take off Typical Vince, the French polisher in him could not resist taking the humble spring and turning it into a star Link to comment Share on other sites More sharing options...
gamve Posted December 20, 2013 Share Posted December 20, 2013 Now all you mechanical engineers have sorted this out I have some very basic questions for you all. Where are the calculations for the spring rates to ensure correct bounce at say 5Hz? I have seen a lot of talk and a distinct lack of actual physics. I take it that he physics are the same for all loadings? Is it just the suspended mass that changes for different turntables that need to be taken into account These calculations with the suspended mass plugged in should tell us the number of springs required, spring height, number of coils, diameter of spring wire for a given material type. (spring materials raises another one hundred questions just on it's own) How do you propose to place the given springs to ensure a dead even loading on each spring ensuring that each spring operates in a dead vertical up/down motion. Or do you calculate the weight placed on say each four corners and calculate the correct spring for each position? How do you propose to damp the oscillation of the suspended mass once the induced vibration stops? How does this system (or a magnetic levitation system) compensate for side loadings caused by airborne vibrations hitting the suspended mass? This topic has been done to death on nearly every forum that has anything to do with sound reproduction. I have yet to see anyone come up with a home grown (read cheap) solution that fits every application. The physics involved (to my understanding) are not simple and are even harder to implement properly given the amount of variables involved. I think it's fair to say that a lot of students have used this very problem as their University thesis with the results being the current range of Vibraplane (and similar) static and active devices on the market mainly used for the mounting of optical equipment. These devices address vibration in all modes and have suitable damping mechanisms They really are the only suitable solution albeit at a high cost. The reason for the high cost being is that It is just not simple equipment you can knock up in the back shed for a couple of hundred bucks. If you have half a chance put the TT in another room or mount it all on a concrete slab. Prevention is cheaper than cure in this case? I wish you guys luck coming up with something that works anywhere near as well as an optical table but I will bet most efforts end up being no better than a concrete paving slab or a piece of slate sitting on series of squash balls, a wheelbarrow tube or similar. Link to comment Share on other sites More sharing options...
lovetube Posted December 20, 2013 Share Posted December 20, 2013 Looks like a direct copy , should ask for royalties don't start it. I can't smell the gun powder Duc 1 Link to comment Share on other sites More sharing options...
samman Posted December 20, 2013 Share Posted December 20, 2013 looks like Vince copied my copied design after all Great to see all you great minds think alike Link to comment Share on other sites More sharing options...
samman Posted December 20, 2013 Share Posted December 20, 2013 Now all you mechanical engineers have sorted this out I have some very basic questions for you all. Where are the calculations for the spring rates to ensure correct bounce at say 5Hz? I have seen a lot of talk and a distinct lack of actual physics. I take it that he physics are the same for all loadings? Is it just the suspended mass that changes for different turntables that need to be taken into account These calculations with the suspended mass plugged in should tell us the number of springs required, spring height, number of coils, diameter of spring wire for a given material type. (spring materials raises another one hundred questions just on it's own) How do you propose to place the given springs to ensure a dead even loading on each spring ensuring that each spring operates in a dead vertical up/down motion. Or do you calculate the weight placed on say each four corners and calculate the correct spring for each position? How do you propose to damp the oscillation of the suspended mass once the induced vibration stops? How does this system (or a magnetic levitation system) compensate for side loadings caused by airborne vibrations hitting the suspended mass? This topic has been done to death on nearly every forum that has anything to do with sound reproduction. I have yet to see anyone come up with a home grown (read cheap) solution that fits every application. The physics involved (to my understanding) are not simple and are even harder to implement properly given the amount of variables involved. I think it's fair to say that a lot of students have used this very problem as their University thesis with the results being the current range of Vibraplane (and similar) static and active devices on the market mainly used for the mounting of optical equipment. These devices address vibration in all modes and have suitable damping mechanisms They really are the only suitable solution albeit at a high cost. The reason for the high cost being is that It is just not simple equipment you can knock up in the back shed for a couple of hundred bucks. If you have half a chance put the TT in another room or mount it all on a concrete slab. Prevention is cheaper than cure in this case? I wish you guys luck coming up with something that works anywhere near as well as an optical table but I will bet most efforts end up being no better than a concrete paving slab or a piece of slate sitting on series of squash balls, a wheelbarrow tube or similar. Personally It doesn't matter to me as the consumer at the end of the line as to the physics or engineering know how that went into development.... It works for my set up and it's relatively inexpensive when compared to other products... Well worth it in my situation,. I Link to comment Share on other sites More sharing options...
kana Posted December 20, 2013 Share Posted December 20, 2013 They should form a coop and share the royalties I would like to be there when the great minds gather to sign the deed Link to comment Share on other sites More sharing options...
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