Best way to isolate glass shelves.

[Del monaco]

This thread has made me paranoid now. I haven’t tweaked for years. Please don’t!
Seriously what is the measured effect of toughened glass on equipment?

 

[stevec67]

I have wondered the same thing. There are sorbothane hemispheres available in a range of sizes. I wonder how necessary these isolation racks would be if the various boxes, amplifiers, preamplifiers etc., were fitted with these rather than the customary feet.

It's not necessary now, but the hifi faithful want something to spend their money on. The idea of isolating something by putting a hard plate on other hard objects with nothing to absorb energy is farcical.

 

[Discopants]

Fo.q ta32 damping tape from Japan can be found on eBay for about £40.

You can dampen all your shelves and plenty more.

 

[stevec67]

This thread has made me paranoid now. I haven’t tweaked for years. Please don’t!
Seriously what is the measured effect of toughened glass on equipment?

The faithful don't want measurements! Have you learned nothing? Things with moving parts like record decks are affected by movement and what they stand on, some valves are microphonic, and speakers change depending on what they are standing on, distance from the floor, etc. These are known phenomena, but standing a solid state amplifier on a glass isolation table is foo on a par with cable supports.

 

[Mr_Sukebe]

Replace the shelves with perspex

 

[Mickdale]

The nuts have a hole in the centre which the ball bearings then sit in so they can't move. So that arrangement is perfectly safe for kids unless they actually rugby tackle the whole thing.

That isn't the Naim set up. They do have the ball bearings in a cup so they can move around, I think that's the point of how they work. Give that a hard enough sideways knock and it will all fall apart.

Naim use 1/2” steel balls sitting in cups. The central aperture of the cups are triangular so there is only 3 point contact (not linear 360 degree).
They also offer plastic rings that stick to the underside of the glass stopping the glass from scraping over the balls if pushed.
As the balls have 3 point contact they shouldn’t just slide about

 

[Rockmeister]

I sort of adopt a 'vague logic' approach. Glass shelves ring when tapped. Some HiFi stuff does put out tiny vibrations, but I think that most of these are soaked up by the makers supplied feet. If not, it makes sense to me to put something under the kit responsible to keep these vibrations from getting into the glass, so sorbathane or etc seems sensible there. Now that the glass isn't 'ringing' from the kit, is it ringing from airborne or structural vibration? If that worries you then yes, some soft but elastic material between the shelf and the frame makes sense. Felt, cork, rubber, blu tac all would do well there at a guess. Now all you need worry about is what's happening where the floor touches the stand, but therin lies another tale.

 

[Arkless Electronics]

Glass shelves can't get coronavirus and therefore don't need to be isolated. just make sure they are at least 2 metres apart

 

[2ManyBoxes]

Naim use 1/2” steel balls sitting in cups. The central aperture of the cups are triangular so there is only 3 point contact (not linear 360 degree).
They also offer plastic rings that stick to the underside of the glass stopping the glass from scraping over the balls if pushed.
As the balls have 3 point contact they shouldn’t just slide about

Thanks for that. I've never been flush enough to actually buy a Fraim, just had a good look in a shop

 

[Mickdale]

It's not necessary now, but the hifi faithful want something to spend their money on. The idea of isolating something by putting a hard plate on other hard objects with nothing to absorb energy is farcical.

I believe the idea is to have two different materials so the energy is not transferred as much rather than being absorbed. Harmonic frequencies of different materials and all that. Gas turbines have known to fail from being run at certain rpm as it coincided with material harmonic frequencies etc.

 

[stevec67]

I believe the idea is to have two different materials so the energy is not transferred as much rather than being absorbed. Harmonic frequencies of different materials and all that. Gas turbines have known to fail from being run at certain rpm as it coincided with material harmonic frequencies etc.

Exactly so. Laboratory balances are used on sand boxes. The top plate on which the balance stands sits on a tray filled with a few inches of dry sand. This measurably isolate s footfall, without it a balance will tell you all about it. When you are weighing to a milligram any loss of isolation just means it will never settle.

As you say anything that will absorb energy will work. Rubber, putty, bathroom sealant, bits of carpet. The sky is the limit.