[geeks] audio issue with PC case

[Rjtoegel]

Only problem with Al foil is that Al oxidizes in air which gives it a
nonconductive oxide coating with makes for lousy contacts.  That's why it's
hit or miss.  Best would be a piece of copper braid from a piece of coax
cable.  Unfortunately it's a bitch to remove from the cable and thread the
audio wires through it.  Another alternative is to wrap the audio cables with
insulated wire with a fairly tight wrap and ground at one end.  That will act
as a shield.  I've used that to cure ignition noise in my HF mobile ham radio
setup.

Bob

On Feb 22, 2014, at 3:06 AM, Barry Keeney <barryk at chaoscon.com> wrote:

> On Fri, 21 Feb 2014, Shannon wrote:
>
>> I have a gaming rig, and I'm currently using on board sound.
> ....
>> That solves the loudness issue, but the case's audio cable picks up
>> noise from the graphics card.
> ...
>> The PC case's audio cable appears to be unshielded, so I imagine that is
>> the problem.
>
>   Easy way to shield the cables is wrapping them in aluminium foil,
> more foil, more shielding. It's cheap and you might already have
> some. Just about anything metal should work, but aluminium foil
> would be a quick cheap test.
>
>   I'd cover the foil with something like electical tape,
> heat shrink tubing, or just plain clear plastic tape (scotch, etc)
> just in case the aluminium conductive, don't want any electical
> shorts.
>
>   I know Some types of aluminium are conductive others aren't and
> I don't know if common household aluminium foil isn't conductive for
> sure or if some brands are and others aren't (I've never tested it
> myself). If you've got a Volt/ohm meter you could test it first,
> but the tape would look better anyway, better safe then sorry...
>
>   I've done this myself in the past for shielding cables from
> electrical noise and it works, atleast most of the time. I had
> one problem with a old air compressor causing problems with
> some speaker wires and I still had a little bit of noise even
> with the aluminium foil, much better then without but I had to
> re-route the cables away from the compressor to clear up the
> problem completely.
>
>   Mileage may vary, I'm not an electical engineer (that's my
> brother), don't play one on TV, etc...
>
> but hope this helps...
>
> Barry Keeney
> Chaos Consulting
> email barryk at chaoscon.com
>
> "Atheist: A person who doesn't need imaginary friends"
>
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>
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