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Thoughts on RCA cables with ‘directional shielding’ e.g. SVS SoundPath

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#21
The question is since the shield is terminated at the source side does the noise go back to ground through the source or proceed along the same ground terminal that is connected to the destination component? It seems like it would be easy to test with one of the cables like that purposely put in a very 'noisy' environment and switch which end the ground is on.

I'm going to be pissed when someone uses my idea and makes a high dollar cable like this, but why don't they have the shielding only connected to an external ground or even sent through a 'noise harvester' type setup to remove the noise. Think how much they could charge for that.
You mean like how you can run sensitive lines through (grounded) conduit for noise isolation?

edited for clarity
 
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Speedskater

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#22
You mean like how electricians run sensitive lines through (grounded) conduit for noise isolation?
Don't know how many sensitive lines electricians run. But very sensitive instrumentation lines are often run without conduit.
Electricians are often required to run AC lines thru grounded conduit. It's a matter of code safety regulations.
 
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John Galt

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Thread Starter #23
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#24
Don't know how many sensitive lines electricians run. But very sensitive instrumentation lines are often run without conduit.
Electricians are often required to run AC lines thru grounded conduit. It's a matter of code safety regulations.
Steel conduit can act as shielding, especially against EMI (and more RFI if it's aluminum conduit).
 

Cbdb2

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#25
Instrumentation is usually balanced twisted pair with shield, the tripple whammy for noise rejection. Twisted pair for low freq magnetic interference, shielded for RF, and ballanced for common mode noise. The shield is much better than conduit, which when used is more for mechanical protection than electrical shielding. Instrumentation unlike audio is often run long distances thru noisey industrial places so these things are needed. Audio, not so much, although on very low signal levels, like cartridges it might be needed.
 
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#27
Instrumentation is usually balanced twisted pair with shield, the tripple whammy for noise rejection. Twisted pair for low freq magnetic interference, shielded for RF, and ballanced for common mode noise. The shield is much better than conduit, which when used is more for mechanical protection than electrical shielding. Instrumentation unlike audio is often run long distances thru noisey industrial places so these things are needed. Audio, not so much, although on very low signal levels, like cartridges it might be needed.
I'm with you on everything except for the part where you said "shield is much better than conduit". Any sources on that? At a high level, if you look at ohms per foot (which is typically a good indicator of EMI shielding effectiveness), there's way more metal in conduit than in a typical foil and/or braid cable shield. Plus, conduit is always 100% coverage. :)
 

TankTop

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#28
I'm with you on everything except for the part where you said "shield is much better than conduit". Any sources on that? At a high level, if you look at ohms per foot (which is typically a good indicator of EMI shielding effectiveness), there's way more metal in conduit than in a typical foil and/or braid cable shield. Plus, conduit is always 100% coverage. :)
Why stop there, why not a loose copper braid on the outside of the cable grounded to the phono stage? I personally don’t think it’s necessary at all but but if you’re going to do it why not go all the way? While we’re at it have your electrician ground the receptacle for your AV equipment to your water faucet outside.
 

Cbdb2

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#32
I'm with you on everything except for the part where you said "shield is much better than conduit". Any sources on that? At a high level, if you look at ohms per foot (which is typically a good indicator of EMI shielding effectiveness), there's way more metal in conduit than in a typical foil and/or braid cable shield. Plus, conduit is always 100% coverage. :)
Just MHO. The shield is usually a lower impedance to ground, conduit impedance at RF must increase when skin depth kicks in, but I dont have any numbers.
 

Speedskater

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#34
The above magazine article is about power line current generated low frequency EMF noise. While steel & Mu-metal work great at low frequencies, at high radio frequencies foil (not braided) copper, aluminum & silver work better.
 
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#35
Just MHO. The shield is usually a lower impedance to ground, conduit impedance at RF must increase when skin depth kicks in, but I dont have any numbers.
Don't you think that a thinner conductor would suffer earlier from skin effect?

Also, I have not seen any literature that suggests that impedance actually increases vs conductor thickness (at any frequency). Of course, this is not the same as the principle behind skin effect where impedance increases vs frequency...
 

Speedskater

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#36
What in the world would 'skin effect' have to do with an RCA interconnect? 'skin effect' only matters when lots of high frequency power goes thru the cable.
* * * * * * * * * * * * * * *
This is just another case of a common audiophile manufacturing marketing trick. They take engineering knowledge out of context and than misapply it to their products. Resulting in very confused audiophiles
 
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John Galt

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Thread Starter #37
What in the world would 'skin effect' have to do with an RCA interconnect? 'skin effect' only matters when lots of high frequency power goes thru the cable.
* * * * * * * * * * * * * * *
This is just another case of a common audiophile manufacturing marketing trick. They take engineering knowledge out of context and than misapply it to their products. Resulting in very confused audiophiles
Hasn‘t Gene DellaSalla from Audioholics pretty much debunked the ‘skin effect’ as snake oil? I wonder if Amir has chimed in on this.

FWIW, I believe there is a LOT of snake oil cable BS out there, but I still want high quality cables for EVERYTHING because I’ve suffered the consequences of low quality flakey cables WAY too many times.
 

DonH56

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#38
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