This is my first post to this forum. I joined just to ask this question, the answer to which I think might benefit others (certainly others with the same turntable as I have, but perhaps others building DIY turntables with separate plinths and bases).
I have a vintage Goldmund Studietto turntable, which is basically a high-quality direct drive motor, platter, electronics, and tonearm mounted to a slab of acrylic-like material (methacrylate) separated from the base--another slab of methacrylate--by three very wiggly and jiggly compressed coil springs that resonate at audible frequencies.
The stock springs are almost universally acknowledged to be the weak point in the design of this turntable, and most owners report dramatic improvements in sound quality from replacing the springs with Sorbothane pucks or something similar. In the past, I have tried several different materials (including various combinations of layers of EAR C-1002 Isodamp, closed-cell polyurethane foam, and some very sticky stuff I bought many years ago from Micheal Percy called Microsorb), and indeed, they all were a significant improvement over the stock springs. I currently have three gray Pandafeet (http://www.positive-feedback.com/Issue13/pandafeet.htm
) between plinth and base, and although I think they do a very good job of keeping resonances in the shelf and base from entering the plinth, I'm not convinced they're that good at neutralizing resonances in the plinth itself.
Thus, I am considering other damping/decoupling materials, including those from HAL. In particular, I was thinking about trying either the extra thick (1/8") 1-5/16" diameter Grungebuster Dots or the 9/32" thick 1-5/16" diameter Giant Fat Dots. The 1-5/16" diameter is ideal for this application because that's pretty close to the diameter of the height-adjustable Delrin spring holders between the plinth and base on this turntable.
So, any recommendations as to which material would be preferable and whether stacked dots would be a good idea in order to increase the thickness of the damping material?
I know these HAL products aren't supposed to be all that weight sensitive, but for what it's worth, the weight on each of the three Delrin spring supports is not evenly distributed. The one of the right side of the plinth about half way between the front and rear carries the least weight; the one on the left side near the front carries a bit more; and the one on the left side near the rear carries the most. I've never weighed the plinth with everything on it, but I estimate that it might weigh about 20-25 pounds.