Through a lot of painstaking trial and error, coupled with a lot of failures and a few successes, I landed on a pretty unique combo of a heavy steel plate sitting on large diameter Sorbothane feet of a specific hardness (durometer) that worked as well as the wooden isolation base I started with at the beginning of our tale. But I wanted more and was about to figure out how to get it.
Interesting to note that all the work I was doing on discovering how isolation bases worked and why was by listening to the system with but one piece of equipment on the experimental isolation base: the Power Plant Premier. I bring this up because one would think that a DAC, preamp or amp might benefit from isolation more than a power product - and they would be right - but I started with the power product and it only made sense to continue. This stubbornnesspaid off in the end and I'll cover this in the power phase of our tale about designing a new concept piece we call the PowerBase.
I had begun to figure out that what we didn't want to do was eliminate or reduce vibrations as much as diffuse them and add them back in. Had this not been the case then everything I did to reduce or eliminate would have had positive effects that we pervasive - and that wasn't the case.
I wondered what would happen if I used two bases - one stacked on top of the other. After all, if one was good why not two, or three or whatever? I built another, identical base and stacked one on top of the other. Wow. The differences seemed greater than just doubled - it seemed to be a non-linear progression and my suspicion that varying densities of mass and diffusion were at the heart of this new discovery.
The next morning, when I awoke, I lay in bed for a half an hour dreaming of the goofy looking stack of two steel plates sitting on each other, wondering how that might turn into a practical product - so good were the results. This waking time is when I have some of my best ideas and as I lay there daydreaming an old product I saw once came into view: the Oasis turntable.
I can't remember much about the Oasis only that it had a heavy platter that somehow floated in a pool of water completely divorced from its base. Inside the Oasis was animpellerconnected to a motor that made the water in the base spin around at the exact right speed. Underneath the heavy platter were tines that, like a windmill, turned the platter in response to the moving water. It was a cool product - not all that practical - but still cool because there wasn't even a belt to connect the platter to the outside world.
As I was remembering the Oasis it occurred to me: why not build an enclosed base - in the same sort of shape as the PerfectWave DAC was - but without a top cover - just a 4 sided closed chassis with a heavy steel bottom plate sitting on tuned Sorbothane feet. Inside the chassis I would mount another set of differently tuned Sorbothane feet supporting another steel plate - floating inside the base. If we made the top steel plate slightly proud of the chassis, then there would be room to compress the plate down into its well when someone placed a heavy piece of kit on it.
So now I had a cool and practical design for stacking two bases on top of each other into one product. The durometer of the inner platform would need to be significantly different than that of the first base to complete the puzzle of different densities, durometers and mass to properly diffuse the vibrations.
After much fooling around and discovering that it is actually beneficial to get the diffused vibrations transferred into the equipment, thus masking the airborne vibrations in a form of dither, we landed on a formula that worked. This was the beginning of the PowerBase. But there was more to come and tomorrow we'll start on that.