Granite surface plate

Audio blazer, don't forget that HRS uses a 0.75" granite platform set in a aluminum shell and sitting on a polymer bed and supported by load specific feet. The surface plate being discussed is 4 times the mass of the HRS.

Granite is useful for isolation, but IMHO, granite needs to be damped to prevent ringing etc.

It will ring like a bell and give you a bright treble balance .Try Symposium its neutral and will give better stage ,bass,midrange etc.

Bpoletti,
I would suggest that you call Adona. I am sure that they would sell you one of their granite shelves. They are the best of both worlds. They bond granite to a layer of MDF with a special (proprietary?) polymer. Anyway, it eliminates problems with ringing etc. Visit the Adona website. I have been using one of their racks for abourt 4 years and like it very much.

I use 3 x granite block samples as feet
for my
turntable. (They are about 4" x 4" x
1.5")
I decouple the plinth from the blocks
with
brass compression rings on their side.
See
my system pics. This way there is no
granite ringing but there is excellent
focus over butcher block.

I don't recommend this.
I have one from a machine shop and it really sounded bright and shrill.
I use a 3" thick maple block and I'm very happy with the warm clean sound wood brings to the table.