[Leo13]

Hello, Been reading AC for months and finally registered for my 1st post.

I'm looking for the most effective way to use the damping material on pcb boards, chassis, and parts (ie. caps). The last being the most important at the moment.
---Does the size of the cap dictate how much dampening material to use?
---when applying the damping material to caps that are dangling around do you damp the the bottom (flush w/ PCB board), just wrap it around anywhere, just the top, or is there a particular method for each type of part?

Thanx for any helpful assistance,
Jon

[SET Man]

Hey!

   First welcome to the AC.

   As for dampening thing. There are a few things that I know that should work well.

   For chassis...

http://www.musicdirect.com/product/72702

   I haven't use this but I've considered it. But due to the size to price ratio it could be expensive if you are going to dampening a large area.

http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=268-010

   The above asphalt is cheaper and even cheaper if you are buying a larger one. I actually have used some of these myself. I put some on the back of my speaker driver cup that cover the magnet and some on the basket legs. Seems to work pretty well. Should work well on chassis also    

  For caps...

   Well, I don't dampening my cap. But maybe I should try. And a bit of those asphalt cut in small strip might work around the cap. Also, check out hardware store, they do sell a very thick rubber electrical tape that could be use to wrap around caps and etc.

   Also, there are other way to dampening caps. This is what Blue Circle use...



  Notice those white stuff on those caps? Yup, silicone. So, maybe a dap of silicone on top of silicone might do. And this should work well on PCB too since it could be conform to any shape.

   But when you are applying these dampening stuff make sure that you don't apply it to any part that get warm or hot and need to be ventilated, and of course not to block any vent.

   I'm not expert on these so maybe other will chip in with their own experience

  Well, have fun and keep us posted on your result.

Take care,
Buddy

[satfrat]

If you're going to use silicone to dampen,make sure it's of electronic variety. Not all silicone is made equally, using the wrong stuff could domore harm than good. In my BPT, I used MG Chemicals Premium RTV Silicone Adhesive Sealant, high strength Electronic Grade #1035-85ml. It's low odor weather proof primerless sealant good for leak resistant gasket seals, for bonding of electronic components onto circuit boards and for isolating. For chassis dampening, I used a little heavier low order dampening sheets than Buddy inside my BPT's chassis and sealed the edges with the silicone. http://www.partsexpress.com/pe/showdetl.cfm?Partnumber=268-030 The inside of my power conditioner ain't pretty but it's damn quiet. 

disclaimer, I'm no more of an expert than Buddy, probably even less knowledgable but this is what I did after talking to the tweekmasters and doing research for safety sake, I present ideas, not facts,,, ymmv

Cheers,
Robin

[Blackmore]

FWIW, my Yamamoto gear has some small value caps covered in a sleeve of ebony.  He drills out an ebony cylinder just big enough for the cap and some epoxy.  Doesn't do that on larger value caps. (could be cost, could be worries about heat??)  Anyway, just thought I'd chime in.  Check out 6moons for the Yamamoto A08 amp and keep looking at the accompanying pictures for the ebony caps.

[Speedskater]

I think that "constrained layer dampening" has a special definition, see:

http://www.greengluecompany.com/understandingDamping.php

Constrained Layer Damping

In a constrained layer damping system, sometimes referred to as CLD, a damping material is sandwiched between two other (usually stiff/rigid) materials. An example is Green Glue sandwiched between two layers of drywall. Damping occurs when the viscoelastic center of the "sandwich" is sheared.

When bent, shear forces pull and stretch on the damping material, allowing the damping materials to dissipate energy.

[sac8d4]

Marigo audio ( www.marigoaudio.com ) has some good info applying their dots to pcb boards and caps.

[Leo13]

I wanted to thank all of you for your feedback! I have individual comments for a few of you, but will leave a blanket statement for now.
Many different ways to damp many different things. A lot of trial and error, if done correctly magic can happen, done incorrect...well that's why not too many people do it
I appreciate the hospitality, links/photo's etc... if any interest I'll post this weeks experiments (positive or negative) on this link.
Regards,
Jon

[*Scotty*]

Jon,You haven't specified whether you are trying to damp electrolytic capacitors,foil and film caps or metalized film caps. If you have a microphonic
electrolytic cap it should be replaced with a new cap that is not defective. If your circuit board is not in a mechanical device like DVD Player or a transport you may have better results if you concentrate on stopping vibration before it enters into the component in the first place by using some form of vibration isolation platform or footers. Aurios   http://www.aurios.net/products.htm  for the footers or a Gingko cloud isolation platform.
I have had effective results on chassis and electrolytic caps using Dynamat Xtreme   http://www.mobilepros.org/xcart/catalog/Dynamat-Xtreme-Wedge-Pack-10425--p-16142.html
Film caps are not particularly  susceptible to vibration being composed of a tightly wrapped roll of plastic film and metal foil. They are largely self damped structures but they should be firmly attached to the circuit board with some sort of adhesive.
Good luck with your project.
Scotty

[Leo13]

Components themselves create their own internal vibrations which need to be dissipated. I use several methods under every component and speaker I own, footers and individual platforms present. Some isolation devices reinforce the internal vibrations which defeats the purpose to me, but some people must like that effect.
What I'm looking to do is isolate and correctly dampen my components until I've reached the point of negative returns. I mentioned the caps in particular because I lack the knowledge and won't be able to fully experiment until this week.
Overall, many ways, materials, and parts to dampen (using isolation devices or not), and many way to do it wrong or not as good as can be done. Some tips from those of you w/ the experience is appreciated.
Regards,
Jon

p.s. I've heard that the Dynamat Xtreme is good for chassis and a few other things, but basically nothing connected to the PCB...loss of the leading edge transients? More experimentation to come.
   

[*Scotty*]

Leo13, What all of your circuit boards populated with electronic components have is an EM field around them. When you place some kind of goop,adhesive,or DOT on the component or circuit board you are affecting the space around the component that the EM field is in and you have replaced air with some kind of solid which has a much poorer dielectric quality. The result of placing the electronic component in close proximity to a big blob silicone for example,would be to reduce the air and size of space that could be reproduced without the blob. You have certainly affected the piece of gear but not as a result of damping self generated vibration. The best sounding equipment,everything else being equal,has circuit boards that are mounted no closer than 1.5in. from any wall in the chassis and are not covered in anti-vibration material. You will do as you please but bear in mind that placing a poor sounding material on an electronic component to achieve a positive sounding result is a hit or miss proposition and no blueprint for this activity that insures a positive outcome
exists. You are stuck with trial and error application of the "dampening" material and it would be a good idea to apply nothing that cannot be easily removed if you don't like the sonic result.
Good Luck,
Scotty

[Leo13]

SET,
Thanks for the links. I have the material that I feel may be best for this app., but am somewhat exploring uncharted waters for the most part...barring more common dampening like speaker cabinets etc...
satfrat,
Never considered silicone as it's difficult to fully remove. May try it on an expendable unit sometime.
sac8d4,
Seen their page, but feltthey were missing a few things.
Scotty,
I agree w/ most of what you said, particularly about air being the best dielectric, but I feel there's more to it. I want to give this a much closer look and experiment & was looking for any helpful advice before I got started. It's helpful to hear from others' experiences as well, positive or negative.
Regards,
Jon