Grounding active earth cable

[Citrus]

Hi

just bought some Beldon active earth cable.

Question is whether the earth drain wire is connected to anything. Ie earth wire.

It cant drain into thin air?

C

[fas42]

A starting point,

 

 

[One and a half]

@Citrus, as you can just make out in the still from you tube, the drain is connected to the receiver side earth connection and not the source side, so one end only.

 

Hmm, I would connect the drain at the source end although in the past connected at both ends. Ideally, the drain should be connected to a greater 100% covered shield, if using foil and drain keeping the noise in or not letting it in is very different between the two types of cable shielding.

 

Could you provide a link to the active earth cable? Not sure how the marketing speak translates to reality. You can have driven shields, or passive shields, but active? Dunno.

[Citrus]

Hi one and a half

Confusion here.

Found this.

what are your thoughts with that?

[One and a half]

8 hours ago, Citrus said:

Hi one and a half

Confusion here.

Found this.

what are your thoughts with that?

Yes, that's the interpretation that's familiar. At frequencies that prefer transmission through a Braid, they won't since there's no circuit other than capacitance between the shield and internal conductors.

So maybe the shield needs to be connected at both ends to shunt these frequencies other than 50-ultrasonic ranges after allq. Worth a measurement but need some very high G ohm probes to verify which I don't have. 

 

Star quad DC cables work with shields both ends or for pro use, since the shield bonds both receiver and source to the close to the same potential.

 

https://audiointerfacing.com/star-quad-cable/

[Speedskater]

While I have no clue what a 'active earth cable' is?

 

I would connect the shield of an AC power cord at the component end, but not at the wall receptacle end.

That way it act as an extension of the metal chassis shield.

* * * * * * * *

If you connect it as pictured above.

It simply acts as an antenna for the leakage, ground & noise currents on the Safety Ground/Protective Earth wire.

[StephenJK]

On 11/22/2022 at 5:59 AM, Citrus said:

Hi one and a half

Confusion here.

Found this.

what are your thoughts with that?

That doesn't compute for a residential power supply cord.  

 

The configuration you're illustrating is intended for use with low level instrumentation signals that could be in close proximity to power cables that have a strong inductive field - meaning three phase power supplies on industrial machinery.  

 

That's why shielded cables with an outer drain wire exist in the first place.  The shield ground should not be confused with the grounding conductor, which has the separate function of connecting the load to the system ground.  

 

The shield, or screen, is grounded on one side only so that the low level signal can't be part of a power supply system where there could be a ground loop, or circulating ground current due to an imbalance (which is quite likely) in the three phase distribution system.

 

The installation of instrumentation, or signal cables along with power cables is part of a fully realized design scheme, where the DC power supplies for the instrumentation array would likely be left floating, rather than having a common ground so they would be further isolated from the power system.  

 

By grounding the shield on one side only, any inductive field would be removed and not affect the accuracy of a millivolt or milliamp signal. 

 

Doing the same thing on a residential power supply cord is much like coming up with a solution for a problem that doesn't exist.  

 

If there is no risk of induction, then why have a shielded power supply cord in the first place? 

 

Edit:  And, not to put a fine point on it, the world's best insulator is air.  If you keep signal cables away from power cables, all of your potential problems go away.  The configuration for balanced stereo connections vs. single ended exists for the very same reason - so that power cables can't induce a voltage into the signal cables when run across the floor willy-nilly in a recording studio or concert venue.  

 

 

 

 

 

[Citrus]

Thanks guys

Interesting stuff.

I was about to do another post about the sound quality of the cable its self but after connecting the shield wire at the component end it seems to have improved the sound.

So basically you are say the wiring is the same as the picture but the shield ground is attached to the component end. Not sure why that works as the shield is still attached to the same earth cable.

the cable ends up at a couple of sockets for the component plugs.

Is this what you mean? I have wondered before about whether my pc should be better grounded or if there was some sort of shielding you could use for that?

The DC cable from my LPS to the pc is a 2 pole gx16 to a 5.5 x 2.5 plug so I’m wondering if extra grounding here might clear things up a bit?

C.

[Speedskater]

When the shield is connect at only one end there is no completed path for the leakage, ground & noise currents to flow.

So it only has one task, that is to act as a shield.

* * * * * * * * *

and yes, shields connected at both ends are sometimes designed to do more that one task.

[Citrus]

Hi

Thanks Speedskater
I’m trying to get some perspective here. (Or even facts)

I bought a few meters of Belden 19364 Audio-Grade Mains Cable

https://www.mcru.co.uk/product/belden-19364-audio-grade-cable/?v=79cba1185463

 

I had been trying out using a mains spur rather than a ring main.

Certainly made a difference taking it of the ring main!

So I had this set up as a trial using heavy duty 2.5mm flex. All sounded great.

I Had 2.5mm twin and earth to a socket. Had to do this cos of regulations. Then the extension to the component sockets, then obviously the component leads themselves.

Thought I’d do it properly with some shielded cable.

Trouble is ‘it just don’t sound good!’

Put the other flex lead back in and all was well again?

The sound of the shielded cable had slightly more clarity but had this really harsh upper mid tone sort of ear aching overload. Always difficult to describe.

It was that sort of sound you’d been trying to get rid of since forever.

Just cant work that one out?

So basically I've now removed the shielded cable and gone back to the flex.

I thought it might be the length of the shielded cable but then tried a 50m extension lead and that still sounded better!

Really don’t know what to make of that one? Hence the post!

C.

 

 

[Speedskater]

AC power cables and cords don't have a sound.

What you are describing is how your audio system reacts to differences in AC power quality.

It says more about your audio equipment than your AC power.

 

[yamamoto2002]

14 hours ago, Speedskater said:

AC power cables and cords don't have a sound.

What you are describing is how your audio system reacts to differences in AC power quality.

It says more about your audio equipment than your AC power.

 

There is power induced hum noise problem and when power cable and analog signal cable runs in parallel, there is a hum noise level difference that depends on the construction of power cable. it is more problematic when analog signal level is low (ex. microphone signal and analog turntable).

 

In the past, I experimented it with 10m power code and RCA analog signal code runs in parallel. Power induced hum noise of cabtire power cable is 10dB (?) lower than VVF power cable. hum noise is always measurably high level and in the worst case setup hum noise is audible from the speakers. Proper shielding and/or using balanced analog signal transferring with XLR (instead of unbalanced RCA) helps further to reduce hum. I think it is possible to experiment with NTSC analog video signal and power cable in parallel, beat noise (image brightness fluctuated) is appeared on the screen when hum noise level is high.

[One and a half]

On 11/28/2022 at 5:20 PM, Citrus said:

Hi

Thanks Speedskater
I’m trying to get some perspective here. (Or even facts)

I bought a few meters of Belden 19364 Audio-Grade Mains Cable

https://www.mcru.co.uk/product/belden-19364-audio-grade-cable/?v=79cba1185463

 

I had been trying out using a mains spur rather than a ring main.

Certainly made a difference taking it of the ring main!

So I had this set up as a trial using heavy duty 2.5mm flex. All sounded great.

I Had 2.5mm twin and earth to a socket. Had to do this cos of regulations. Then the extension to the component sockets, then obviously the component leads themselves.

Thought I’d do it properly with some shielded cable.

Trouble is ‘it just don’t sound good!’

Put the other flex lead back in and all was well again?

The sound of the shielded cable had slightly more clarity but had this really harsh upper mid tone sort of ear aching overload. Always difficult to describe.

It was that sort of sound you’d been trying to get rid of since forever.

Just cant work that one out?

So basically I've now removed the shielded cable and gone back to the flex.

I thought it might be the length of the shielded cable but then tried a 50m extension lead and that still sounded better!

Really don’t know what to make of that one? Hence the post!

C.

 

 

The Belden is a copper cable, perhaps your preference is silver. Silver plated copper had the advantage of being very resistant to environmental issues like gasses and humidity. Soundwise it can cause upper glare on b&w speakers, I use KEF so not a problem.

[One and a half]

11 hours ago, yamamoto2002 said:

There is power induced hum noise problem and when power cable and analog signal cable runs in parallel, there is a hum noise level difference that depends on the construction of power cable. it is more problematic when analog signal level is low (ex. microphone signal and analog turntable).

 

In the past, I experimented it with 10m power code and RCA analog signal code runs in parallel. Power induced hum noise of cabtire power cable is 10dB (?) lower than VVF power cable. hum noise is always measurably high level and in the worst case setup hum noise is audible from the speakers. Proper shielding and/or using balanced analog signal transferring with XLR (instead of unbalanced RCA) helps further to reduce hum. I think it is possible to experiment with NTSC analog video signal and power cable in parallel, beat noise (image brightness fluctuated) is appeared on the screen when hum noise level is high.

I totally agree, the back of audio equipment has power leads very close to signal leads, parallel runs are easy to create with cables doing what they want to do at times.

 

Never again will use unshielded power cables in the rack, especially when bundled with multiple power cables. 

 

When using an induction wand (not the greatest tool) it does provide a guide if induction from power cable is present, or the shield has fallen off.

[Speedskater]

On 11/29/2022 at 4:46 PM, One and a half said:

The Belden is a copper cable, perhaps your preference is silver. Silver plated copper had the advantage of being very resistant to environmental issues like gasses and humidity.

I doubt that you can find a 'UL' listed silver AC power cord or cable.

 

Lack of silver plating doesn't seem to be a problem anywhere in the AC power grid.

[Speedskater]

Silver plating is great for high frequency signal cables, say above 100 megahertz. Silver plating is required for Teflon® insulated cables. Other than those it's just wheel spinning.

[One and a half]

On 12/2/2022 at 12:04 AM, Speedskater said:

I doubt that you can find a 'UL' listed silver AC power cord or cable.

 

Lack of silver plating doesn't seem to be a problem anywhere in the AC power grid.

Flippant remark per usual. Milspec is good enough for UL? I bought several metres for AC power cabling, sources only, easy to fit off compared to the Furutech and Oyaide. In any case UL doesn't apply in AU, the cable is rated to 600V, still has enough headroom for 230V peaks.

[Speedskater]

When I wrote 'UL' listed, I had hoped the readers would understand that they could substitute the  applicable safety agencies in their country.

The above Milspec link is not for a silver conductor cable and it doesn't look suitable for an AC power cord.

[yamamoto2002]

In Japan, all power cable in the market should be <PS>E approved, and it is strict rule with custodial sentence sanctions