An isolation platform for the SB3

[zanash]

As the sb3 sits on the rear foot and two little feet under the main body ...its actually quite a light weight setup. Mine has been draged back wards with heavy cables. The plastic construction will not help damp micro vibration getting to the dac and other micro phonic components.

So I decided to try and make a base that would address these issues.

I had everything I needed in my research and development complex [shed] ....

1 x granite placemat tesco's finest
1 x 5mm rubber sheet
1 x 18mm mdf sheet
2 x metal strip drilled
2 self tapping screws
1 x no nails glue
3 x 25mm dia felt feet

using the granite as a template I cut the rubber and mdf to size.
I then glued the rubber sheet to the granite, whilst setting I then marked out on the mdf the position I wanted the sb3 to sit, in my case about 30mm back from the short side. I then bent the metal strips to form loops to go over the round metal rubber rear support. Drill out and screwed the strips on ...I had to dremel off 1mm of protruding screw....so check there length before you fit them.
The mdf sheet was then glued to the top of the rubber and clamped ...with the sb3 attached in my case. then fit the three felt feet to the underside of the granite.

When the glue had set I fitted the sb3 back into my system ...
What I noticed was a greater resolution and better dynamics ...don't get me wrong its not huge. But the total cost was less than £8 and I've now got a very stable unit thats not pulled across the self with heavy cables.

[killie99]

any chance of a photo?

[zanash]

if I can work out the correct image size ....

[singleended40]

I am using three pieces of Ebony wood (knife handle size- two in front and one in the back) between my SB3 and another two inches thick hard red wood.

[zanash]

I'm planning to sit the whole on top of a set of iso feet ..by davidf on zerogain.com

these are wooden discs with a ball bearing ...the effect on my cd were stunning considering the very small cost of these units [£15 for 3 feet depending on size]

fitting these under my quad 99cdp2 for the first time was a real shock as I then discovered how much music was being lost.

[Deaf Cat]

photo :) photo :)

[ezkcdude]

I'm planning to sit the whole on top of a set of iso feet ..by davidf on zerogain.com

these are wooden discs with a ball bearing ...the effect on my cd were stunning considering the very small cost of these units [£15 for 3 feet depending on size]

fitting these under my quad 99cdp2 for the first time was a real shock as I then discovered how much music was being lost.

Zanash, if you want the ultimate vibration isolation platform, try a floating or hanging suspension platform. Simply get a large heavy steel or aluminum plate (as heavy as you can find), attach clamps to all four corners, and hang the platform from a frame using elastic bungee cords. You may need to use 3-4 bungees per clamp. In grad school, I made such a platform using a 200 lb steel plate, with 3 bungee cords on each edge. My lab had serious vibration problems due to HVAC system in the ceiling. Anyway, the hanging platform virtually eliminates all vibration above 1-2 Hz. There still may be some lateral movement, but the high-frequency vibration is gone. Much better than any "isolation feet". Try it, if nothing else, your friends will be impressed. If you want, I can dig up a picture for you of what I'm talking about.

[Deaf Cat]

photo :] photo :]

[ezkcdude]

Ask and ye shall receive:

http://i122.photobucket.com/albums/o246/ezkcdude/hanging.jpg

Note that the tennis balls underneath the platform are not in contact - they are just a safety measure in case the worst should happen (i.e. the bungees break!).

[Deaf Cat]

Cheers!

Did you have a chance to try a cdp or amp on it :D ..... ?

[killie99]

Cheers!

Did you have a chance to try a cdp or amp on it :D ..... ?

The bungee cords would need to be cryo'd before you could use it for your hifi :)

[ezkcdude]

Well, that would probably affect the bungee elasticity in a negative way ;)

Anyway, one simple test anyone can do to qualitatively analyze the amount of vibration in the system is shine a laser pointer through a shallow (clear) glass dish of water, so that the point of the laser ends up on a wall. This will very clearly illustrate vibrations. Of course, the laser pointer must be mounted on the vibration platform, and it needs to be turned on automatically (in other words, don't touch it while performing the test).

[zanash]

or use a stethoscope....

like I said !

[Porter]

Silly question...

Since when is a DAC "microphonic"? It's a solid state component.

[ezkcdude]

Silly question...

Since when is a DAC "microphonic"? It's a solid state component.

What is a DAC? Is it a chip surrounded by an empty PCB? If so, you're correct. Of course, I like to add things called capacitors for decoupling. These can be microphonic. You know?

[zanash]

I've modded many music fidelity xdacv3 for people ..there always amazed at the effect of a couple of £ of bitumen damping on the case and on the chips. I don't pretend to understand the science behind why ...I just know they do and you can have a large impact on the final sound by deadening ....

I can confirm that its well worth the effort to control these "micro vibrations" in the sb3...

[Deaf Cat]

Hiya,

When you say bitumen, the only things I can think of are flash band (used to bodge roof repaires) or, the paint or trowel on mastic - runny or rather gooie black bitumen, for roofing again.

The flash band would be the less messy of the three I guess, is this the type of stuff you are talking about?

[zanash]

Thats the stuff I use ....its cheap and effective

[Deaf Cat]

hmmmm Cheers :) I've some in the shed.

You say on the chips also, a tiny bit of flash band, and on any part of the internal case thats free....? Just double checking before I may start playing :)

Oh have you found an easy way to remove it just in case,

:)

[zanash]

cut a small peice that sits on the top of the chip ...also cover the crystal and if you can do the case without hindering any function....

removal ...a warming with a heat gun will soften it up once the main part is removed any small sticky bits can be removed with a solvent try an alcohol based one ie meths but there are others that work.

[Deaf Cat]

Cheers Cool :D

I think I will start with the cheapest bit of kit, - never actually contemplated un screwing and taking apart hifi components before :o

All good fun :)

[zanash]

pm me or give me a ring if you want to talk things over ....!

[Skittler]

Any chance of that photo for the Tesco's Finest solution :)

[Deaf Cat]

pm me or give me a ring if you want to talk things over ....!

Cheers, will probably take you up on that when I get the chance to play :)

[maniac]

Silly question...

Since when is a DAC "microphonic"? It's a solid state component.

Quite simply, it is sensitive. There are numerous documents from the chip manufacturers that recommends how best to isolate their chip from vibration. I believe National had some docs on that, and it is quite an interesting read.

Please also do remember the wonderful effect of piezoelectric in our ceramic SMD caps, where it will twist and turn as the PCB flexes under stress (gravity IS one of that), and thus generating a bit of electrical interference.


I have a very interesting personal experience with a Perpetual DAC, P3A. It is a DAC styled to stand "UP RIGHT", and me and my buddy was just thinking what would the difference be if it is lied down flat on the stereo rack. We were wondering what exactly would we be hearing. We reckoned the difference would be so slight, we'd have a hard time hearing it.

Well, we were quite wrong then. The difference is like night and day, the sound stage opened up, and the overall sound become more solid, have more flesh and blood if you will.

That is for something that is just a DAC, no moving parts maybe except some of the oscillators in there. (IIRC P3A have two XOs)


IMHO, I now follow the rule of "try it a few times before laughing at it..." when doing stuff related to audio, because I was kinda laughing at the idea of setting the DAC flat at the time, and found it laughing back at me rather quickly.