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EMI/RFI shielding for USB sound card

nqa3

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Jul 18, 2020
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Has anyone done that before? The sound card isn't contained in aluminium case like most DAC or amps and that might explain some people have noise issue.

I found a few options:

- aluminium case with customization for holes, like Amplifier DIY Box 100% Aluminium or Extruded Aluminum Enclosure (aluminium 6063)
- storage box (to hide the ugliness) with nickel coated copper mesh inside - same material as EMI gaskets
- 3M EMI tape to cover most surfaces of the card

which one would offer best protection?
 

ZolaIII

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Jul 28, 2019
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The transformer varnish & graphite powder applied in multiple layers all together 2~3 mm thick over sensitive parts (DAC, AMP, oscillator...). Biggest advantages; very lite, dose not cost much & you can do it yourself. End result is far better than even thick aluminium enclosure.
Best regards.
 

Bob-23

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Jul 3, 2019
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Berlin, Germany
Has anyone done that before? The sound card isn't contained in aluminium case like most DAC or amps and that might explain some people have noise issue.

I found a few options:

- aluminium case with customization for holes, like Amplifier DIY Box 100% Aluminium or Extruded Aluminum Enclosure (aluminium 6063)
- storage box (to hide the ugliness) with nickel coated copper mesh inside - same material as EMI gaskets
- 3M EMI tape to cover most surfaces of the card

which one would offer best protection?
An Alu-case - though not the best shielding of all materials - should do it. (I build my headamps in alu-cases.) As far as I can see my dac is also in alu, and the ODAC, e.g., is in alu. The one on your link looks nice, but consider the heatsinks on the outside (which you don't need) to become a beautiful dust attractor. I wouldn't operate with tapes. Don't forget the correct grounding (at one single point of the case only).

Edit: Just saw the other case, so no heatsinks, ok., making the openings won't be that easy, in general, depending on your tools and skills. If your not that experienced and don't have the adequate tools: an alu-case with just a plastic front may work, too.
 
Last edited:

Bob-23

Senior Member
Joined
Jul 3, 2019
Messages
425
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379
Location
Berlin, Germany
Has anyone done that before? The sound card isn't contained in aluminium case like most DAC or amps and that might explain some people have noise issue.

I found a few options:

- aluminium case with customization for holes, like Amplifier DIY Box 100% Aluminium or Extruded Aluminum Enclosure (aluminium 6063)
- storage box (to hide the ugliness) with nickel coated copper mesh inside - same material as EMI gaskets
- 3M EMI tape to cover most surfaces of the card

which one would offer best protection?
Just had another idea: put your dac (with the case) on a (copper) groundplane which, of course, has to be grounded. Just try it out, or take any other metal which you have at home, the closer the (internal) pcp to the groundplane, the better. That might even work in an complete plastic case, if the groundplane is put directely under the dac pcb. With a wooden amp I did so, and it worked perfectly...
 
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