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Minus k Technology BM-8 Isolation Platform

Just wondering if anyone out there is using one of these to isolate their turntable. It is a passive design using what the company calls negative stiffness isolators.  Very clever design. You really have to see a picture of the isolator    https://www.minusk.com/products/bm8-vibration-isolation-platforms-bench-tops-isolators.html
It looks to me given the specification that you could isolate any turntable with one of these as well if not better than SME, Basis and SOTA  do with their designs. It is not much to look at and at $3000 it is not exactly cheap but it would be a miracle for someone with foot fall and feed back problems. I personally think equipment racks are unattractive and will not have one in my living room. My equipment is hidden in an antique armoire. I'm thinking about replacing my old suspended turntable with a new one and this platform would give me a lot more flexibility and choice.  Just wondering if they really work👩‍🦳
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looscannon
rsf507
2,233 posts
 
The Vibraplane uses slip plate technology as well as air bladders per the manufacturer.
mikelavigne
2,156 posts
 
the big issues with a Minus K for a turntable are;

(1) the turntable design needs to have it’s weight evenly distributed on the footers.....so it can be centered. some turntables have more weight to the back for instance. it needs balance to ’float’ and decouple.

(2) the floor needs to be solid below the rack. if it’s moving around then you cannot stabilize the Minus K and it will be ’nervous’....reducing the performance.

a vibra-plane, or even better a Stacore, can work with a floor not solid. they are passive air bladder type devices and while not as effective as a Minus K, are not as needy for stability.
varyat's avatar
varyat
145 posts
 
Or you can do what Mark Dohmann has done with his turntables and actually engineer the table around a Minus K suspension.....
spiritofmusic
828 posts
 
Mike, you're right in your observations. My rim drive tt is asymmetrically loaded, and in my short, frustrating trial with it, I absolutely struggled to sort this. Additionally I needed to mass load the MK to get close to it's limit, and of the three slabs I used, I could "hear" them clearly. 
No go for me.
whart's avatar
whart
2,976 posts
 
I have the BM-1, which was spec’d for a 250 lb load. I am in an old restored Victorian with springy wooden floors and the Minus K does work to effectively isolate the table- a Kuzma XL with an Airline am- from footfalls. Where I ran into problems was trying to add a second arm, with arm tower. I could not get it to center and fully isolate in all planes -- part of it was due to the fact that there were multiple heavy pieces to the turntable assembly at different distances from the center, but I suspect height of the mass factored in. Here’s where I was with it a year ago: [url]https://thevinylpress.com/app/uploads/2019/04/Kuzma2arms-sized.jpg[/url]
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