[Andrew LB]

I've always used Mogami or Canare cable, but this headphone cable is using Viablue EPC-4 which has 4 conductors wrapped in silvered foil, and around that is a braided silvered copper mesh shield, and then the jacket. I'm guessing that i should solder both the shield and foil to the sleeve along with the two ground conductors? And as per usual leave the mesh shield and foil floating at the splitter where i plan on just using the twisted wire wrapped in Viablue cable sleeve up to the headphone plugs? IIRC all the other cables ive made had either one or the other, not both shield and foil.

 

[tomb]

Sounds reasonable, although you should test the foil for soldering before trying it for real. Sometimes that stuff is actually a metalized mylar and not really solderable.

 

[gimmeheadroom]

If you're that worried about noise you ought to be running balanced. And like I said in that other thread, the white paper on the Benchmark site says they don't tie the shield to the ground lug on analog XLR connections but they do tie it for AES/EBU cables because they're concerned people will string the AES/EBU cables together and have a noise problem.

 

[tomb]

If the shield is not grounded on at least one end, where does the stray capacitance and other interfering signals go? You might as well connect an antenna to the cable bundle.

 

[gimmeheadroom]

I don't know. That's what the paper said. I'll try to post a link next week.

 

[gimmeheadroom]

https://benchmarkmedia.com/blogs/application_notes/grounding-xlr-connectors-neutrik-usa

Anyway, in the OP's case he's basically using a cable with 5 conductors for a 3 pin signal. Probably the better idea would be to use a 2 conductor cable with shield and use the shield as the ground lead.

When I make RCA cables, I use a two conductor shielded cable and I tie the shield to ground. When I make AES/EBU cables I use a two conductor shielded cable and use the shield as the shield (ground). But I'm not tying the shield to the plug for my applications.

 

[tomb]

https://benchmarkmedia.com/blogs/application_notes/grounding-xlr-connectors-neutrik-usa

Anyway, in the OP's case he's basically using a cable with 5 conductors for a 3 pin signal. Probably the better idea would be to use a 2 conductor cable with shield and use the shield as the ground lead.

When I make RCA cables, I use a two conductor shielded cable and I tie the shield to ground. When I make AES/EBU cables I use a two conductor shielded cable and use the shield as the shield (ground). But I'm not tying the shield to the plug for my applications.

Seems like that article is only addressing the shield tab in an XLR connector itself, not the shield in the cable that the OP is asking about. Even then, it sounds like they use it as the way to ground the wire mesh, which is what I do, too.

Just to be clear, I consider the wire mesh as the shield, not the foil that he is also asking about. Although, it's simple enough to ground the foil mechanically, even if it's not easily soldered. (A mechanical connection between mesh and foil is probably actually inherent in the cable construction.) When one works with antenna cabling, the wire mesh and foil are pulled back to both make mechanical contact with the F connector outer shell. As I stated above, it seems reasonable enough to ground it in a headphone cable, even if there's no way to do that at the headphone connections to the cans.

It ensures a path to ground for stray signals and interference that might penetrate the signal cable wires.

EDIT: It's also a damn shame to waste all that "shielding" technology and construction in a quality cable bundle, by not using the shield/foil. I see so many posts about cables where people simply rip out the multi-conductors in a Mogami or Canare cable so that they can braid them. It think that's a huge waste, just to make something look pretty.

I think you know this, but try braiding some individual conductor wiring to make a pair of RCA interconnects. Then try measuring the response in even a normal environment compared to a pair of properly shielded RCA cables. Even RMAA testing will show this up as a huge difference in noise. Heck, the interference can be plainly audible in a pair of headphones if you connect a DAC to a headphone amp with unshielded RCA cables and there's other electronic equipment nearby.

 

[gimmeheadroom]

Seems like that article is only addressing the shield tab in an XLR connector itself, not the shield in the cable that the OP is asking about. Even then, it sounds like they use it as the way to ground the wire mesh, which is what I do, too.

Just to be clear, I consider the wire mesh as the shield, not the foil that he is also asking about. Although, it's simple enough to ground the foil mechanically, even if it's not easily soldered. (A mechanical connection between mesh and foil is probably actually inherent in the cable construction.) When one works with antenna cabling, the wire mesh and foil are pulled back to both make mechanical contact with the F connector outer shell. As I stated above, it seems reasonable enough to ground it in a headphone cable, even if there's no way to do that at the headphone connections to the cans.

It ensures a path to ground for stray signals and interference that might penetrate the signal cable wires.

EDIT: It's also a damn shame to waste all that "shielding" technology and construction in a quality cable bundle, by not using the shield/foil. I see so many posts about cables where people simply rip out the multi-conductors in a Mogami or Canare cable so that they can braid them. It think that's a huge waste, just to make something look pretty.

I think you know this, but try braiding some individual conductor wiring to make a pair of RCA interconnects. Then try measuring the response in even a normal environment compared to a pair of properly shielded RCA cables. Even RMAA testing will show this up as a huge difference in noise. Heck, the interference can be plainly audible in a pair of headphones if you connect a DAC to a headphone amp with unshielded RCA cables and there's other electronic equipment nearby.

Nice post. You and I are reading the Benchmark paper the same way. I think what I tried to say was regarding the OP's TRS, he would have been better off using a 2 wire + shield and the shield would double as a ground and a shield. The difference between that an an XLR cable would be that you have to go out of your way to ground the XLR connector, but for TRS just using a 2 + shield gives you the benefit of shielding + ground in one shot. So I still don't get why people would buy 3 wire cable for TRS.

Regarding the foil, the foil is wrapped around the ground without any insulation in the cables I have seen. So you get the benefit of a grounded double shield even if you don't do anything with the foil. At least that is my thinking. Is there cable with foil that is not in contact with the braid?

As far as antennas go it has been a long time since I made BNC or PL-259 leads. But I remember only a braided shield and a teflon insulated single core wire. I don't remember an extra layer of foil like we have in good shielded analog and digital cables. Maybe that's why I kinda ignore the foil if it's there and just expect it to be grounded by contact with the shield.