Support Shelf for NDX

Mike-B posted:

 

NDX also means ND anything or any streamer type unit,  its going to happen anyway (sometime) so I would like to make it to a design that works & avoid stuff that does/might degrade SQ.   My questions to the forum are for those that have experience of adding a support shelf (bought or DIY)   (a) Does a support under a streamer actually make a sonic difference (honesty please)  (b) whats the best shelf material;  glass, slate, plastic, wood  (c) ditto support types, spikes, inverted dome nuts, washer/balls, sorbothane, hard rubber,  fixed firmly to the shelf or not.  

............  

Yes - it does. I've asked my local supplier to make some glass shelves, in toughened black glass - size matches the Fraim glass shelves.
Each shelf sits on 3 VibraPods, providing the necessary isolation. Note: a VibraPod under the front-right corner is firmer (transformer sits here). VibraPods are relatively inexpensive (around EUR 45 for a pack of 4).

The differences are not subtle at all - it is probably the best and the most obvious upgrade I have ever heard.

I will add a photo in a second (if I can find it).

Adam

And here it is...

Hi Mike,

I've tried:

Sorbathane feet
8.8mm laminated glass (450mm x 350mm x 8.8mm)
8mm toughened glass (450mm x 350mm x 8mm)
Glass resting on the wood
Glass + dome nuts
Glass + Sorbathane
Glass with 3 points of contact, glass with 4 points of contact

The best was 8mm toughened glass resting on 3 dome nuts.

It's night and day - literally: The ND5 sits on the glass 24x7, so literally night and day .

There was also significant gain in SQ over the bare Alphason rack, not an enormous gain, but quite significant and it is consistent.
There was a similar gain placing the Nait XS on an identical glass arrangement.

The gain in SQ wasn't as much as replacing the 'Lavender' with W2549, but it was more than replacing the "other interconnect".

Mike:

I tried a lot of different options too but elected to go bare .. wood that is .. 3" cherry shelves with 3 X black walnut circular uprights per shelf .. I found the NDX liked to be on the top shelf, as did the 282 which sits in the next rack over.

John.

John,  love the wood looks absolutely stunning sets off the Naim gear.

Top marks John,  nice looking shelf.   I do not have the space or the audio cabinet design that lends itself to a design with the upright columns,  but wood is one of the shelf materials I am considering.  Now your chunky 3 incher's have got me thinking along a slight deviation to a basic 1/2 or 3/4 inch support platform.  Is the wood a solid chunk of real wood or a veneered composite?  Are the uprights hard screwed or glued to attached to the shelves??. 

Mike:

Thanks for the comments (and you PCD).  It's all solid wood .. the uprights are screwed into the shelves creating a discrete 3 legged "table".  I removed one of the screw hole caps to show the screw seating.  

John

The following picture shows the shelf from the underside.

Good stuff John,  thanks for taking the trouble.  The photo also shows me the shelf end grain & that tells me the answers to some other questions.  Now all I need is the time to design & make.

Mike - from some of the tests I've done I found that Naim boxes are much happier sitting on toughened glass.

Perhaps a glass shelf, with isolation, on that beautilf wooden shelf?

Thanks Adam,  don't worry I'm soaking up & cogitating all the possibilities - plus other people have ideas about nice looking & that will need to get approval first.  This one is a slow burner & with being a bit busy taking over domestic duties for a while my best estimate on completion will be ..............   hmm I'll have to think about that one.

Sounds like a nice project ahead

Enjoy the music over the weekend.

Hi Mike

I use the Vibrapod supports like Adam, however I also have the vibrapod cones, these have a ball bearing at the top which the shelf rests on,which sit on top of the Vibrapod, I have 4 supports under a 6mm glass shelf and I found it did make a big difference at a cheap cost, I use these on my NDX and 252 pre.

Haven't tried using 3 supports or not using the added cone supports but all in all, well worth trying

Thanks Duncanm,  I'm now pretty certain to be going the glass route, I tried with some mockups yesterday but can't get John's chunky wood idea to blend into the cabinet design (blend = think WAF).  

I'm sorely tempted to use domed nuts & probably will try them anyway once I get fixed on glass.  The problem I have is leveling (which dome nuts don't have) but I am troubled by how much the Vibrapods Isolators compress under weight,  they are 9/16 inch which in real numbers is 14.3mm,  but how much do they squish down & what weight grade to use.   In use the Vibrapods will not be seen so I can move them around the glass to get an even squish compression (I hope) & I will be trying to use 3 rather than 4 under the shelf.     The NDX is 10kg so it looks like the model-3 is the one to go for with a range of 3.62 to 5.44kg each.  So a question to you & Adam,  what Vibrapod Isolator model have you used & how much do they squish down.

Mike-B posted:

  The NDX is 10kg so it looks like the model-3 is the one to go for with a range of 3.62 to 5.44kg each.  So a question to you & Adam,  what Vibrapod Isolator model have you used & how much do they squish down.

They compress down to approximately 10 mm. With NDX I use the following:

• 2 x number 3 (on the left and at the back)
• 1 x number 4 (this one under the front-right corner, where the trafo is)

I could get away with mixing and matching because of the number of VibraPods I needed for all components.
Also I found one needs to go up in a VibraPod number to get the best of it - hence using no 3 and no 4.

Mike, I have the model 2 vibrapods which squish down to 15mm height and 38mm when used with the cones. The model 2 will support 4 to 8 pounds each so using 4 supports is 16 to 32 pounds total and NDX as you say is 10kg or 22 pounds. I do wonder if I should have gone for the Model 3 as they do seem to compress quite a bit.

OK thanks to both,  it confirms my original selection of model-3 to be good for 10kg,  I'm tempted to try 4x model-3 & use 2 close(r) together in the traffo area.  (remember they will not be seen)   10mm squish will work perfectly for me with 8mm glass,  it will be OK to be a few mm more but needs to be perfectly level  (my eye line vision is a bit OCD) 

Sounds good Mike.

Make sure the glass is toughened / tempered. Somehow works better with NAIM.
I chose a 10 mm thicknes to replicate the Fraim glass.
Also glass shelves have sides to them - one always resonates more. If you tap it with your knuckles you will hear a small difference. The more resonant side goes up.

Glass with biased sides !!!   Holy Banana Plugs Batman !!!   you will be saying cables are directional next 

Mike-B posted:

 you will be saying cables are directional next 

Me? Never....

Update:   The rack top glass support shelf for the NDX - bottom line first - it hasn't worked too well.    I've tried dome nuts in various positions, vibrapods & soft sorbothane.  The SQ changes between them all were subtle at best, vibrapods the winner by a nose.   I used Model 2 vibrapods & found even spacing on the 4 corners of the glass was not ideal, the NDX slowly tilted towards the heavy traffo end, only by about 1mm,  but it was visible.  The same when aligned with the NDX feet.  I worked out the NDX C/G point & set the vibrapods equidistant out towards the NDX corners (16cm),  although this was nothing like an even spacing on the glass, that was not visible,  but the NDX now sat level & its vibrapod wobble seemed better.  But was the SQ better than the mastic bonded fixed shelf in the previous location,  not really.

Next was domestic goddess approval, she didn't like the cables sticking out the back, DIN (blue), Burndy (black) , Optical (grey), RC5 (black) & Ethernet (blue) - TBH, neither do I.   

So its still W.I.P.

Hmmm...

An idea - what if you just put that glass shelf right on top of the wooden one. No vibrapods, nothing, no nothin'

Just glass on wood.

I don't think so,  I designed the rack shelving to be correct visually for the "Classic" case size & adding even a thin glass will spoil that & I don't expect it will do anything for a positive SQ change,  Plus I think I've now proven to myself the design I put into the rack with the mastic bonded shelves to be dead/inert has been difficult to improve on.   With the top (old TT position) that I was hoping to use, its not working out,  but I'm still working at it.  The big problem,  given that up to now there is no real SQ improvement so nothing positive to bring to the project,  the cables sticking out the back is not so nice even for me & as it is it will not been signed off by the Director of Domestic Engineering. 

Well - that's good news then, isn't it? You have a rack which is clearly very good.

Just enjoy it. And the music too

Maybe,  I designed (& tested) the rack with CDP's.  I have in the past experienced & fixed CDP sound issues caused by vibration from external & internal (traffo) vibration,  I went about the rack design with some understanding of potential CD laser accuracy effects & that gave me the ideas to test with my prototype shelving.   This exercise in the last week clearly shows that streamer isolation is not the same,  not even close. 

Hi Mike. What does your rack look like? What did you do to fix CDP sound issues caused by vibration? I have a CDX2 and don't have a decent rack yet, it's on the list.