Isolation Question - Vibrapods, Spikes, etc.

[nightflier]

I suppose one point that has not been raised is: what do the manufacturers think about this? For example, if a $3K cd player still comes with $.50 rubber feet, then the manufacturer is probably not in agreement that fancy sorbotane feet are necessary. Certainly at this price point, with an ample budget for research, this would be addressed by any good manufacturer. Now correct me if I'm wrong, but I have yet to see a high-end cd player with factory spikes, so my guess is that spikes are probably not the best solution for cd players.

Looking at my MMF7 turntable (which has almost no hum/noise to my ears), it has 3 spikes for the table to rest on and the latter is actually a two-layer table seperated with sorbotane cushions. The platter/spindle rest on the top platter thus being isolated with the sorbotane cushions from the lower platter. The mottor is in a hole through both platters so that it has no contact with them and the only link to the platter is via a rubber band. From this, I gather that a spinning motor must be disconnected as much as possible from the component and that the spinning platter (& disk) must be as near to floating in free space as possible.

While I understand that TT's translate analog vibrations in the groove and that this is far more sensitive than digital, I am still surprised that even some of these measures are not implemented on most CD players under $3K. As a matter of fact I would go so far as to argue that under $3K, all stock CD players are a wash as far as isolation/coupling, and that the difference in sound is more a function of electronics than physical attributes. Only at the higher price points do these factors become audible, I guess.

Ironically, there are a number of DIY sites that describe in detail how changing the physical attributes of average cd players can make them sound noticeably better. Perhaps these modified players are not giant killers, but with a good DAC I imagine they give those $3K players a run for the money. I've even noticed that just placing a heavy book on some CD players improves the sound.

After all this, however, I'm still wondering about the use of brass spikes (like the Mapleshade ones). Aside from a specific elements of a turntable, I do not see how they would benefit any other component. Some people swear that even solid state amps should be well coupled to the floor, but I have tried this too and honestly have not noticed any audible difference.

Any thoughts about amps?

[hermanv]

I had a Conrad Johnson solid state amp (MF2300A - 240W/channel) driving Martin Logan ReQuests. Because of the room being too small and prodigious heat, it ended up on top of my Oak entertainment cabinet. Like most modern furniture, cheap, and not as sturdy as one might hope. My vacuum tube pre-amp and C-J DAC mounted inside needed help to stop a certain hollow woodeness in the sound because the cabinet itself sounded that way.

So I says to myself, what you need is a nice slab of marble to cover the top of that entertainment cabinet maybe 3/4 or 1" thick something with real mass, sturdy. I got one cut from a remnant at a counter top place, weighed about a hundred pounds and was sort of affordable (don't remember the exact price). I put this accross the very top of the cabinet and parked my nice amplifier on top of it.

It sounded - dare I say it - Glassy. When the marble was tapped it sounded like a nice thick sheet of glass and this character was evident in the music. I finally found some rubber pedestal feet that could support the 85 or so pounds of amplifier and all was well.

Wiser now, if I did it again it would be sandstone, something solid but sonically inert.

Ever since then I wince whenever I see these commercial "audiophile" racks with glass shelves. Haven't heard them, but I'm quite suspicious that glass is just the wrong answer.

[nightflier]

hermanv,

How would granite work? (it's a lot less expensive and easy to find)

[hermanv]

hermanv,

How would granite work? (it's a lot less expensive and easy to find)

I'd be guessing. Any material that's both massive and well damped is probably a good choice. If you tap on granite with a small hammer does it ring or ideally, just go thunk?

If you read the Mapeshade stuff on shelves, it begings to make some sense. A nice hard and solid wood, heavy and reasonably well damped. Perhaps the Maple (I think that's what they push) has just a touch of wooden body, maybe not so bad a thing for those digital recordings that so often seem sterile.

[Hyfi]

hermanv,

How would granite work? (it's a lot less expensive and easy to find)

Granite or Flagstone are similar. I used my Granite Toolmakers Surface Plate for one amp (4" thick, and a 1" thick slab of Flagstone on top of Tennis balls for the other. Niether amps vibrate when music is at loud levels. I also use 1" thick slabs of flagstone under my speakers. I wanted to post a pic but this site only allows itty bitty resolution pics and mine are all 3/4 meg.

I played around with this theory a bit with different stone including slate, which had good results but the reddish flagstone matched my carpet and had better results.

[hifitommy]

makes things easier. i went to a meeting in a guy's house in a gated community where he had things like duntech speakers (bigger and heavier than i am), speaker cables fatter than garden hoses, and the like.

the sota TT/smeV was not running but the wadia transport/da system was and the sony scd 1 sacdp. craig goff was there with aurios and i was sure he would put them under the transport but NO, under the d/a they went.

if i hadnt heard this myself, i would have thought it was BS. the bass extended downward about another 1/2 octave and firmed up.

solid state passive (physically) device improved with horizontal isolation. go figure. i mention this only because people tend not to believe that isolation can work on non-moving-parts components, just as i did.

if you have the extra cash and you have the wherewithal to carry out these experiments, sometimes it pays off. myself, i try what i can afford:

http://db.audioasylum.com/cgi/search...chtext=toysrus

it worked for me in my application.

[hermanv]

There are many commercial products that act upon vibration. If it doesn't have the audiophile packaging much of this stuff is cheap and easy to experiment with.

Blu tack costs more than gold, but museum tack at a five and dime (showing my age) is used to hold display plates and such on a shelf (seems identical to me, except color) is dirt cheap.

Ditto rubber feet, rubber balls (super balls are a bad choice they store rather than dissipate energy) you want something that doesn't bounce very well. A tiny inner tube for maybe a wheelbarrow costs a whole lot less than an "air isolation platform" basically the same idea, maybe not as pretty. You need a top and bottom slab of some sort.

Bricks are cheap, well damped and heavy, not pretty but useful for a test maybe wrap them in a cloth?

My local "natural fibers" carpet store has a wool carpet underlayment about 60% wool, makes great absorbing panels for walls at about 1/50th the cost of commercial wall treatment, not as pretty, I suppose you could dye it or put a cloth wall hanging on the front of it. The natural color is a dirty redish brown. I believe wool is the most accoustically absorbant common material

Parts express sells damping paper a sort of tar paper, I was warned it smelled bad, the smell really wasn't noticable and the wife didn't panic. I used on the bottom of all my wood shelves and that cheap thin plywood at the back of all modern cabinetry.

Anyway the commercial stuff is big money and you're not that sure how much if any it's going to help. So even if you plan to go with the brand name pretty and expensive stuff, the alternates I mentioned will let you try ideas with having to mortgage the house.

[nightflier]

Bricks are cheap, well damped and heavy, not pretty but useful for a test maybe wrap them in a cloth?

Actually, I have a friend who coated two bricks with rubber and uses these as low monitor stands. He used black, but said that different colors are available. Sure looks better & a little more applicable to a living room than gray.

[hifitommy]

Actually, I have a friend who coated two bricks

dont you mean cement blocks? bricks are pretty small. and back east we used to call them 'cinder blocks'.

i think hermV meant bricks as weights like the vpi magic brick (not really a brick).

[nightflier]

Yes I meant cement blocks.

[hifitommy]

i live in sylmar. do you belong or thought of joining:

??

http://www.laocaudiosociety.net/

lots of great meetings including upscale audio. check it out.

[nightflier]

Tommy,

Thanks for the info. I'm not a member but that sounds like a good group. I'll check it out.