Isolation platforms for turntables

I have built my own - very high mass plus anti vibration material and springs. I have no feedback issues at all now.

Symposium Ultra DOES NOT isolate anything. It changes the resonant frequency of what it is supporting, nothing more.

For less than $100 try compression springs.

http://www.flickr.com/photos/13641350@N08/9323033263/

Sounds better than my Symposium Ultra which now sits under my amp and my SRA platform made specifically for my TW turntable which sits in its box alone and lonely. anyone want to buy it?

Altanpsx,

Vibraplane platforms come in passive & active-air isolation versions. both have limitations from a practical point of view. the cheaper passive version relies on a hand-pump to manually pump & level the unit's internal air reservoirs which slowly deflate over time (more on this below). the active-air isolation version needs to be attached to an outboard air compressor which can be impractical for some people (even tho the compressor is reputed to be quite silent & only comes on periodically).

the main problem i have with the passive version is its lack of self-leveling. this has resulted in several "compatibility issues" during my years of ownership. i've had heavy record clamps tilt the entire platform when applied / removed (affects tonearm's antiskate & tracking angle) & thus required frequent platform leveling & re-leveling. this attribute also causes it to be completely incompatible with most linear tracking arms.

all in all, it required considerably more effort than i'm willing to put in (regardless of performance) & i've opted to replace mine with an active isolation platform from Herzan.

Sorry 11flat6 regarding your compatibility problems with the passive Vibraplane. When I sell these units (now more than 6,000 sold world-wide) I never would sell a passive version to anyone that was going to use it with a linear tracking tonearm. I myself have owned the ET2 tonearm and know what you are talking about.

(Dealer disclaimer)

12-20-13: Altanpsx
Bconero117 i think vibraplane is an electron microscpe platform, and it costs 2-4 kish. But it has its own problems like air pump tanks etc... If it worths sure i may consider.

VP is made for microscopes. I own a few and they are reliable from Day one.
But there is one detail to think about, NEVER move the VP when the feet are filled. All air loss is based on that mistake. But this is noticed in the manual.
When they are new and filled first, the air hoses will be stretched a little bit, so refill has to be done about 2 or 3 times after 2 weeks, when the hoses have their final diameter all is stable. For mine I refill them probably all 4 months.
Car Tires for example need a check too, based on diffusion.
The VP can also ordered in active version (compressor).