[Mark T. Montgomery]

I read a post hear that talked about how easy and effective it is to shield components in amps and cd players.  Where do I get the copper and what parts shoud I shield? The transformer ect. ect.  O and does the copper have to be glued to the what I am shielding? Thanks...

[WerTicus]

no copper is shit... use something called NUMETAL or mild steel - they absorb stay crap better.

as to location ... well put it around stuff that sends out crap or put it around crap you dont want recieving stuff.

mkay?

[Kim S.]

I have some questions about sheilding also.  This summer I bought some metal sheets from Music Direct that were suppose to aid in vibration control.  The outside layer of the sheets are stainless steel, an inside layer is a "viscoelastic damping material".  I applied some of these sheets to my cd player and dac.  I noticed an inprovement in sound, more detail, quieter background.  I mentioned this to an "expert" and he suggested that the inprovement may be due to RFI sheilding and not vibration control.  I have since installed more sheets on my amplifier chassis and achieved further improvement.

My question is this.  Does the sheilding material used, be it copper or something else need to be grounded to the chassis?  I am guessing that the "viscoelastic dampimg material" in my case is a nonconductor so the sheets are not grounded.  However some threads I have read tell you to ground the sheild.  To me that seems as though that would change the sheild to a RFI antenna, directing the nasties to the component.  I would appreciate enlightenment

[Malcolm Fear]

Go to your local electronics hobby shop (RadioShack, perhaps) and buy blank printed circuit board, double sided if possible. This is a sheet of fibreglass with a sheet of copper on both sides.

[cryotweaks]

I would use a layered combination of adhesive Copper foil, and stillpoints ERS.

Copper foil + ERS + Copper foil

You only need a small amount of ERS, a 1:8 ratio of copper to ERS should do nicely.

I sandwich small strips of ERS between layers of copper braided sleeving for a cable shield and it works incredibly well.  

Try www.mcmaster.com for the copper

Good info on shielding here: http://www.parker.com/chomerics/tech/EMITHEORY.htm

DISCLAIMER:  I am a distributor of ERS.

[JoshK]

Go to your local electronics hobby shop (RadioShack, perhaps) and buy blank printed circuit board, double sided if possible. This is a sheet of fibreglass with a sheet of copper on both sides.

thanks for the tip.  I just wonder if the holes will minimize its shielding affect?

[Kim S.]

I thought of the copper circuit boards from radio shack to put on top of my cd player and amp.  I think the copper would look better than the metal strips I already have  on the bottom and sides.  This leads me back to my original question.  Would not a single sided board be better with the nonconducting side in contact with the chassis?

[Occam]

Mark,

I think it important to distinguish as to what specifically you are trying to shield against. If your souce of interference is hum induced by alternating magnetic fields ( from a transformer, inductor, or mains power feeds) then mumetal (or mild steel for lower cost, do not use stainless!) is an appropriate choice.

If your intent is to shield agiainst RFI (or signal crosstalk) copper is an ideal mechanism to insulate with a Faraday shield.

Mild steel will function far better as a RFI blocking Faraday shield than copper does in eliminating magnetically induced interference....

As to the benefits of esoteric materials (ERS, etc...), I've know experience with them and wouldn't know.

[bubba966]

When I pulled apart my Pioneer DV-AX10 to find out why it was so heavy (it's a 54 pound DVD player... ) I found a whole hell of a lot of copper.

There were many large 1/8"-3/16" thick copper plates throughout the chassis dividing various components from each other. All appeared to be grounded if I recall properly.

There were also a few different places where there was a very thin copper sheet that was laminated between 2 pieces of plastic then mounted over some of the circuit boards. Don't recall if those were grounded or not.

[JoshK]

I've thought about doing something like that Brian with my amp.  Wonder if I'll get much benefit from it.

[bubba966]

I've thought about doing something like that Brian with my amp.  Wonder if I'll get much benefit from it.

Well the DV-AX10 is a much better transport than any other DVDP Pioneer ever built (and it's not a small difference), even the DV-09.

And while the DV-09 is built in much the same manner that the DV-AX10 is, the 09 isn't shielded nearly as much as the AX10 is.

So I can only assume that the immense amount of copper shielding is helping quite a bit. It has to be doing something positive. Otherwise they wouldn't have gone to the extreme lengths they did inside that thing. I can't imagine how much engineering it took to design that thing. It's a huge player, and yet there's no wasted space inside. If it's not components, it's shielding.

[JoshK]

The trouble is, I wouldn't know what to ground and what not to, or does it really matter?

[bubba966]

That I don't know for sure. Most of the plates separating the various sections of the player (analog, digital, video, power, etc.) seemed to be grounded if I remember.

But I wasn't looking for that when I was in there. I was just curious what things were like inside.

Hopefully one of the more knowledgable EE types around here can better answer that because I'm curious too...

[bubba966]

Maybe you can look at a stereo component the same as a PC motherboard.  Do not make contact  metal to metal.  But you can put copper between a toroid and the bottom of the chassis wher a lot of EMI flows.

Shorting out a circuit is simply observing where there is bare metal and avoiding contact.

That is the exact reason that some of the copper sheets in my DV-AX10 were laminated in plastic. Because they were mounted directly over the underneath of various PCB's. And if they just placed a sheet of un-insulated copper in the same place, it would've most certaily shorted something out.

If I ever pull it out & open it up again, I'll have to make an effort to notice if any or all of the shielding is grounded or not.

[Mark T. Montgomery]

Thanks for all the help.  All I'm trying to do is get the best sound out of my CD player and amp.  And I'm still not axactly sure where and how to place the copper in my units.

[Malcolm Fear]

The circuit boards I have purchased had no holes. It is a solid sheet of fibre glass with a sheet of copper on each side. Then there is a layer of insulation over the copper.
My line of thinking is "If one is good, then 2 is better".

[elektratig]

For those of you looking for metals for chassis, shielding and other uses, take a look at Online Metals, http://www.onlinemetals.com .

Adire Tempest Sub Construction Pix: http://www.audiocircle.com/index.php?action=gallery;area=browse;album=130