Granite is reflective as a polished hard stone. It can cause ringing. I would recommend a wood layer that you can drain vibration into via spikes. the wood with spikes is a common stand type which is fairly cheap but constrained layer damped shelves are also good but more expensive choices.
I would try wood by itself as an experiment to see if you prefer the sound. No spikes, just wood. Spikes under any equipment can cause the sound to become lean.
At first thought it seems like a good idea, but in practice granite is a poor choice for an amp stand.
IME granite makes for a drier, harder edged sound with far less bass bloom. In fact, I would say harmonics, the natural decay of the music is vitally disturbed.
I use a 2" thick concrete patio slab 20" square (cost $3). Up on tiptoes (old stock have had for ?25 YEARS. $28 when new) , with the amp on size ten butyl rubber bottle stoppers on top of the slab.(another $6)
Cheap as can be and works great.
Granite may 'ring' a tiny bit, but it may not, depending on how the amp sits on it. Personally I have never been able to hear a chunk of granite make any sound, or feel it vibrate in any way.
PS if you have to ask this: guess what: IT DOES NOT MATTER because you don't hear any difference anyway.
IF YOU did hear a difference, then you would not be asking...
You are worried about the granite 'in theory' WHY???????
Do you just worry about useless stuff? And guess what.. asking here will get you a dozen different 'theories' right back, Not ONE of them is worth a damn. as they are all just 'theories' too! They can't 'hear' your amp on it's granite stand, only YOU can. Rant over.
(Sometimes it IS neccessary to kick butt...LOL)
And I apologize if the op feels hurt by my rant...
And if the granite ringing in theory bothers you, add a constrained layer of damping material to the bottom of the granite.
A dirt cheap version would be a self stick vinyl flooring tile. just stick on the bottom. problem solved. in 'theory anyway.
Depends how thick the granite is. I use three inch thick granite at are lake system without issue.
Solid state amps aren't generally susceptible to the things there put on.
I have tried many different materials under my amps, preamps, cd players and turntables. My 3" granite slab is among the worst sounding of them all, no matter what type of couplers or damping materials are used. I don't believe the problem is as simple as "ringing" because it's hard to believe a 180lb slab of anything is ringing. But the granite does have serious colorations and they are unmusical colorations---they interfere with my enjoying the music.
I recommend trying some different types of wood instead of the granite. Each type sounds different and different thicknesses of the same wood sound different. You just have to try some yourself and reach your own conclusion about what you like best. My bet, however, is that the wood will sound much better than the granite.
A safe recommendation is to use a shelf platform made of 3/4" Baltic Birch void-free plywood. I have found this to be very neutral tonally with good dynamics and detail. Don't be tempted to use 1" Baltic Birch (too dull in the treble) or some type of plywood other than Baltic Birch. And whatever you do, stay away from mdf. Despite lots of companies using it for equipment shelves and speaker cabinets, mdf is also among the worst sounding materials.
Wood might work, but pay special attention to grain orientation, which can be easily heard. Its far worse than ringing. Wood is even more directional than a fuse, and you wont want a grainy sound.
My, my. We have so many 'material scientist' on the forum, all doing in lab experimentations. Great, especially the wood grain orientation from Mike60. Me, I use some steering wheel covers I got at Target for $4 each. Works wonders. So why do we see so many glass equipment stands?
From my experience, the worst material is glass. Followed from such stones. You can find a lot of different designs, wood, wood filled with Sand or lead, Plastic (ok, it has a different name which allows to get a higher pricing)...some years ago I tried more or less by accident a Vibraplane below my amp (I used it normally below my turntable) and I closed that chapter immediately. What is made for electron microscopes is ok for High End :-)
"Granit amp stands are they killing my sound?"
The major issue with granite slabs is low frequency vibration activated by either bass frequencies from speakers or seismic type vibration. Placing the granite slabs on suitable cones can minimize the tendency of granite to vibrate. I would not use a granite slab thinner than an inch and a half. I like bluestone slabs from Home Depot because they are thick and inexpensive.
I could imagine a lifeless sound coming from a granite slab ... but suggesting the granite is actually killing the sound could be cause-effect confusion.
Syntax, could you please describe the effect of placing a Vibraplane under your Lamm amps? I have one under my turntable, and I agree with you. It is so effective that I closed that chapter.
I have heavy SS amps sitting directly on my floor. I'd like to try two Vibraplanes under them, but it will be an expensive experiment. Any advice or comments you may have would be appreciated.
what I heard in the very first second was a different sound staging. More like a view into a Hall, very clean details and a pure tone.
Not a change in tonality you can read from users when they try different stands, hard to describe, my first reaction was "Huh???" (I was not really expecting that, I thought, ok, the usual little bit from this here and there...) but it is amazing when you listen to records with a deep soundstage (London from 1960 for example)...or Adele, Live at The Royal Albert Hall :-)
Thanks Syntax. Those results seem impressive. Are your amps the Lamms with tubes, SS or hybrid? Do you think the most improvement with the VP would be with tube amps or would SS also benefit so dramatically?
I'm thinking of getting two of the active units with a compressor in the basement.
Sorry to sidetrack this discussion about granite amp stands.
the first experience was done with ML2.1, later with M1.2R
You shouldn't need to locate the compressor in the basement (if you're going to use a compressor like the Jun-Air). My Vibraplane's compressor is so quiet, it sits out in the listening room, no more than a few feet from my listening position - even if it happens to kick on while listening, all you hear is the click of the relay tripping, it runs for about 20 seconds, and that's it. I believe they were designed to run dental tools - sharp pointy instruments and sudden loud noises don't go well together! Aesthetically, the compressor is a bit of a conversation piece too.
Are you using the Vibraplane under your Galibier or for something else?
Yup, under the Galibier. I ditched by sandbox in favor of a mass-loaded active Vibraplane. I'm using two sheets of 3/4" aluminum on top of the Vibraplane for mass loading to get within the optimum range of effectiveness, or around 250 lbs. The difference is not subtle.
Thanks Palasr. I'd like the compressor out of site. I know they can be quiet as I've heard a Jen-Air? at Sounds of Silence, the Vibraplane distributor. I just don't want one in my formal living room. I wish I had a dedicated audio room.
I also have my passive Vibraplane preloaded with one 1 1/8" plate of steel weighing 136 lbs which brings my total load to 250 lbs. I agree, the improvement is very noticeable.
Air is great for isolating a component like a turntable and I'm sure it can be effective with amps. But when it comes to draining vibrational energy away from a component, there may be better solutions. Perhaps the OP is more interested in draining energy with spikes into a massive platform then he is in isolating his amps from floor born vibrations.
Have you tried putting your Galibier up on spikes or cones on top of the aluminum sheets? That may address both objectives.
My turntable rests on four small ball bearings at the center of each adjustable footer. These drain the energy away from the turntable/motor while it is being isolated with the Vibraplane. I have the option of using four rubber inserts instead, but have not tried them yet. I've been told the ball bearings sound better.
Have you tried putting your Galibier up on spikes or
cones on top of the aluminum sheets?
Well, that is the difference between High End and Science. When I go into a Lab
and tell a technician he should use cones below his equipment, he will throw
me out in..well..let's say...30s.
In High End the result is the other way..Cones??? Great idea!!!! They have
different sound? Super! There are cheap ones and expensive ones out there?
GREAT! A piece of paper below them can make all the difference??? WOW, I have
to buy that paper.... Made in a cave in Mongolia for 1250,--$ / square foot?
... and so on
I have a VPI Superscoutmaster/rim drive. I found that rubber or anything compliant under the table (as in footers) makes the sound "rubbery". I use Bearpaws...(Vermontaudio.com). They are very heavy brass cones and they really clean up the sound from the VPI supplied minifeet.
I get your point Syntax. Very funny post! Explain what is between your amps
and your Vibraplanes. Also between your MS and Basis turntables and their
Vibraplanes. Do you think a hard ball or point sounds different from some
rubber footer/insert under the components? If they sound different, surely
science is involved.
It would seem possible that granite may not jive with all amps. I would try directly on the floor vs. on the stands. For about a year I had my monos directly on the floor with the intention of some kind of stands. As you all know for anything nice well there's another $300+ each. So I ended up using 3" thick butcher blocks. I can't say it altered the sound in anyway, besides that was'nt the goal. They look fine to me and were on the cheaper side. Anytime I want to play with placement they easily allow for sliding of the amps. I suppose if using some spikes under the amps into the butcher blocks it would help drain any vibrations.
I never suggested that the Granite slab would resonate and ring like a bell. What I meant was because it is a hard polished like glass it may reflect/feedback and cause other objects to resonate. I don't know if this is universal, but it seems quite plausable. Mirror like surfaces are best avoided in audio land, that's all.