Not nuts. Just be aware that all these materials sound different, and the theory behind the layers- constrained layer damping- is to combine different materials with different resonance characteristics to arrive at a fairly neutral solution. I’m not sure acrylic is best--I have one remaining shelf from my Grand Prix racks that I bought long ago still in use- all the others were upgraded to carbon fiber, but even in that rarified club of fancy racks, they are not necessarily a favorite among some these days. On the cheap, folks seem to like the sound of maple. Granite- not so sure. I have an HRS platform that is some composite of granite with polymer damping in a billet aluminum frame- there is some know how that goes into this and I couldn’t tell you that it is better or worse than a comparably priced platform. I use it mainly because my turntable- a Kuzma XL-has no platform; it is all separate parts that stand together and weigh around 186 lbs. With the HRS underneath it, another 58+ pounds. The HRS is not really a full blown isolation platform. At least it wasn’t for me- it didn’t isolate footfalls on a wooden floor. For years, I used mass loading of a very heavy mahogany table with thick chunks of sorbothane under the mahogany table legs, and put the HRS and turntable on that, but even with all that mass, it was less than ideal. I now have a Minus K.
But before you get spendy on isolation, research some of the threads here on DIY platforms and sonic characteristics. Some of the industrial racks used for scientific equipment, used, could be a bargain. In fact, Minus K sells a nice welded steel stand with phenolic top-- like the counters in labs that don’t stain-- for under a grand. (It provides no isolation but is just a stand).
Congrats on a high mass table. I really enjoy mine. I mentioned in another thread on isolation that there is a company called Newport that makes isolation device components- depending on weight, that might be a cost effective solution. I’ve not used the Townshends but those were on my radar as well. In effect, you need a stand with a decent platform and isolation. The units that do all of that can get pricey, and might be better found used. I know there are fans of Symposium platforms here, but I’ve never used one and can’t comment on their use or application.
The DIY route is good if you know what you are doing- otherwise, you are buying supplies, and paying someone to cut and possibly, help assemble.
I used DIY (with contractor help in cutting and assembling) out of such materials as marine grade plywood, mass loaded vinyl, green glue, and those heavy rubber stall mats. This stuff was used mainly for floor support, not turntable isolation as such. It still added up by the time I was done buying the material and paying the contractor (reasonable) to do the cutting and heavy lifting.
Sorry I’m raising more questions than I’m answering, but...
