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

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John Galt

John Galt

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Thread Starter #41
I think this discussion turned me on to the Camry of cables...Mogami. Reasonably priced, solidly specs, very few negatives if any. That’s all I wanted...a cable that’s high value and will never make me think that I’m choking performance with a POS cable.

The SVS SoundPath that I just put on my subs seem to be high quality, and sound just as good as the reasonably priced (but not bottom barrel) cables that they replaced. The Mogamis for LCR should arrive soon, and I expect them to be similarly boring, which is fine with me.
 

Cbdb2

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#42
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
If your talking about my post, read it again. I was talking about shielding RF where skin depth does matter.
 

Cbdb2

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#43
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...
I was saying that the RF impedance of steel conduit increases and thus its shielding decreases at those freqs. due to skin depth.
 
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Cbdb2

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#44
I think he's talking about skin effect in conduit... although to your point, I'm not sure why.
Some one who actually read my post. Just explaining one reason conduit as RF shield ( someone else brought it up) is not as good as a shield in the cable.
 

Cbdb2

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#46
Henry Ott in his 'Electromagnetic Compatibility Engineering" book, has a 62 page chapter on "Shielding". And it's way more complicated than skin depth.
No kidding. Tough crowd. Does he say skin depth dosnt matter? Than I dont get what your getting at, I mention it as one factor, as the impedance of the shield is an important parameter. Which part of " explaning ONE reason" didnt you get?
 
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John Galt

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Thread Starter #47
New SVS SoundPath RCAs for my subs, and new Mogami Gold RCAs on all three monoblocks.

They both appear to be very high quality, flexible, solid connectors (non-molded, repairable). They don’t sound any different than the decent cables they replaced, but I’m more confident now that no audible shortcomings are due to possibly marginally constructed cables.
 

CDMC

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#48
Just purchased a pair of 2 foot directional RCA cables from Worlds Best Cables. In their case, they are directional, as they ground the shield at one end but not the other. The impressive part is they actually include a sheet in the package explaining why and how they terminated the cables. $24 for the pair, with amphenol rca plugs and Canare L-4E6S cable.
 

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John Galt

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Thread Starter #49
Just purchased a pair of 2 foot directional RCA cables from Worlds Best Cables. In their case, they are directional, as they ground the shield at one end but not the other. The impressive part is they actually include a sheet in the package explaining why and how they terminated the cables. $24 for the pair, with amphenol rca plugs and Canare L-4E6S cable.
They look like a better value than the Mogami Gold. Nice cables.
 

Timbo2

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#50
Just purchased a pair of 2 foot directional RCA cables from Worlds Best Cables. In their case, they are directional, as they ground the shield at one end but not the other. The impressive part is they actually include a sheet in the package explaining why and how they terminated the cables. $24 for the pair, with amphenol rca plugs and Canare L-4E6S cable.
They are currently out of stock, but WBC also makes fully shielded versions of Amphenol RCA ended cables with Mogami wire for the same price. In small quantities I can't get the wire and connectors much cheaper than the full assembled patch cables. I love the Amphenol ends. The Mogami is a smaller gauge than the Canare, but for short runs is more flexible. I have pair on my headphone amp. DAC, EQ stack.
 

CDMC

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#51
They are currently out of stock, but WBC also makes fully shielded versions of Amphenol RCA ended cables with Mogami wire for the same price. In small quantities I can't get the wire and connectors much cheaper than the full assembled patch cables. I love the Amphenol ends. The Mogami is a smaller gauge than the Canare, but for short runs is more flexible. I have pair on my headphone amp. DAC, EQ stack.
I have a slight preference for the Mogami, but as you said, sold out right now.
 

Speedskater

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#52
They look like a better value than the Mogami Gold. Nice cables.
There are many, many coax cables (including Mogami) that are much more suitable for a RCA interconnect than the above.
But if for some reason, you must use a StarQuad cable for a RCA analog interconnect (never for a S/PDIF cable) then:
a] attach one wire to the center pin at both ends.
b] attach the other 3 wires and the shield to the shell at both ends.
* * * * * * * * * * *
but on the other hand, for a 2 foot interconnect, it's won't matter.
 
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#53
Some one who actually read my post. Just explaining one reason conduit as RF shield ( someone else brought it up) is not as good as a shield in the cable.
I'm still not getting this part. Why would a thicker shield be a worse shield?
 

CDMC

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#55
There are many, many coax cables (including Mogami) that are much more suitable for a RCA interconnect than the above.
But if for some reason, you must use a StarQuad cable for a RCA analog interconnect (never for a S/PDIF cable) then:
a] attach one wire to the center pin at both ends.
b] attach the other 3 wires and the shield to the shell at both ends.
* * * * * * * * * * *
but on the other hand, for a 2 foot interconnect, it's won't matter.
I couldn’t find a coax based one at the same price. Blue Jeans makes a really nice one that is flexible, but by the time I pay for shipping, would be twice the cost.

https://www.bluejeanscable.com/store/audio/LC1-design-notes.htm
 

Cbdb2

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#56
I'm still not getting this part. Why would a thicker shield be a worse shield?
Depends on the material, conduit is usually steel, which is a lousy conductor at RF compared with aluminum,which is where you need a good conductor for shielding.
 

Cbdb2

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#57
The thikness that is being used depends on the freq because of skin depth. So even if your pipe has 1/2inch walls only a fraction of that will carry cerrent.
The impedance is Z=sqrt(jwu/r+jwe). u is the magnetic permeability which is about 10000 higher for steel than aluminum ( steel is magnetic). So everything else equal aluminum has 1/100 of the impedance of steel at RF. Aluminum conduit works. Other factors: never seen a conduit run into a rack (usually a RF noisey spot(most have network devices)) so never 100% coverage. Nough said about something no one here will ever use.
 
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#58
The thikness that is being used depends on the freq because of skin depth. So even if your pipe has 1/2inch walls only a fraction of that will carry cerrent.
The impedance is Z=sqrt(jwu/r+jwe). u is the magnetic permeability which is about 10000 higher for steel than aluminum ( steel is magnetic). So everything else equal aluminum has 1/100 of the impedance of steel at RF. Aluminum conduit works. Other factors: never seen a conduit run into a rack (usually a RF noisey spot(most have network devices)) so never 100% coverage. Nough said about something no one here will ever use.
I see where you're coming from but steel would still be the superior option when it comes to EMI. Sure, for RFI, go ahead and use aluminum.

https://www.analog.com/media/en/training-seminars/tutorials/MT-095.pdf
 
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#59
directional shielding is like a magic motor
You are missing the point. The shielding isn't directional in the way you seem to be suggesting. It is only connected at one end of the cable and it is recommended to be connected at source end. If you want to be pedantic you could say the shielding is directional as it can only flow in one direction since the connection is only at one end. As you see, there isn't anything magical about it.

Personally for best isolation I would rather see an external connector so the shielding can go directly to an earthing point.
 

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#60
You are missing the point. The shielding isn't directional in the way you seem to be suggesting. It is only connected at one end of the cable and it is recommended to be connected at source end. If you want to be pedantic you could say the shielding is directional as it can only flow in one direction since the connection is only at one end. As you see, there isn't anything magical about it.
So far, so good.
Personally for best isolation I would rather see an external connector so the shielding can go directly to an earthing point.
No, it should attach to the chassis at the source (output) connector.
But for unballanced RCA interconnects, the shield shoud connect at both ends.
What is an 'earthing point' ? the words ground and earth have so many different meanings.
 
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