Medical Isolation Platforms


Decided to open a discussion on Vibraplane, Halcyonics, Minus-K type tables. What are the merits of active vs passive and industrial vs medical? Is the fuss of setting up compressors and tubing worth the benefits of active and is the only difference with industrial vs medical the mass load? Would a cheap passive platform be an upgrade over say a Symposium or BDR Shelf?
ducatirider
I've tried plenty of shelves, feet, ect... For me the Vibraplane was the best of the bunch followed by the Grand Prix Audio stuff. I think if you are just looking for one platform for say a turntable or CD player the Vibraplane is great. You do have to mess with it every say 2 weeks as they do slowly leak air, but man o man does it ever improve a turntable or CD player immensely. It probably requires about 1 minute of your time every 2 weeks to keep it level and pumped up the right amount. Grand Prix stuff is almost as good and it is totally no fuss. After having a Grand Prix rack and not having one and then having one again, I consider it a pretty important piece of the system if you have a good one.
What accessories do you need to maintain its performance? Is there a specific compressor type? I take it you (Ejlif) use the passive platform type.
Minus-k and Halcyonics are comparable in vertical-isolation performance and both are superior to the Vibraplane. The Minus-k systems are passive and have resonant frequencies (0.5 Hz) that are an order of magnitude lower than pneumatic isolators. Once set up, a Minus-k table needs no maintenance. In contrast, the Halcyonics units are active and require 110 V; they are also much more expensive. The extra $$ buy you somewhat better horizontal isolation compared to Minus-k; however, it's not clear that this offers much benefit in audio applications.

I have Minus-k systems in my laboratory for an atomic-force microscope and a surface-plasmon imaging apparatus. The effectiveness of the isolators can be readily measured with those instruments. What motivated me to buy Minus-k units for the lab was the obvious sonic benefit of mounting my turntable on a Minus-k BM-8 isolator at home. In my view this remains the most cost-effective upgrade I've ever done.
 
Sdlevene - could you speak to reasons for choosing the particular Minus-k model that you did, versus, say, the BM-6 or BM-10? Thanks in advance.
 
Jtimothya,

The BM-8 is their highest-performance isolator for loads in the 100-lb range and has the additional advantage of a low profile (about 4 in. high). I replaced the standard top plate with a 28x20x0.75-in slab of polished granite to support my VPI TNT 'table. The sum of these masses (minus the mass of the original top plate) comes just within the maximum load rating of the BM-8.