moryoga wrote,
"I have it on pretty good authority that Vibraplanes are the only truly legitimate isolation platform. I think that this is confirmed by the fact that an air based isolating platform is what is used in all real deal labs and research facilities. For light weight gear you can "mass load" meaning adding a steel plate or other level, stable weight to fulfill the platforms weight requirements. I have three, one exclusively for my tt, a Basis 2800. I’ve added a 110lb steel plate and it sounds truly awesome, much better then before I added it."
Actually while Vibraplane is one of the first audiophile vibration isolation stands it is certainly not the only air type platform nor are air type platforms the only "real" isolation devices. Actually Vibraplane used to be a microscope stand that was marketed to the audiophile market. Prior to Vibraplane there was the Townshend Seismic sink, another air spring (I.e., mass-on-spring) device. I introduced Nimbus almost twenty years ago, another air spring device. Bright Star also had an air spring device. And there were a bunch of others, like Relaxa magnetic levitation, Vibrapods, etc. The Minus K device employs "negative stiffness" which is not an air design to achieve super isolation performance. Vibraplane and my Nimbus employed heavy mass mounted below the air springs to preload the platform but more importantly - in the case of Nimbus - to provide much needed lateral support since my Nimbus used only ONE air spring. Obviously preloading reduces resonant frequency of the device. Mechanical steel springs and, say, bungee cords work the same way as the Vibraplane, as a low mechanical pass filter.
geoff kait
machina dynamica