DIY DC power cables

[Speedskater]

On 8/4/2017 at 1:08 PM, R1200CL said:

If any is interested in reading more about shielding:
Bonding Cable Shields at Both Ends to Reduce Noise

Keith Armstrong is an industrial EMI/RFI expert with countless papers.

Tony Waldron is in the large pro audio systems industry.

 

On 8/4/2017 at 1:08 PM, R1200CL said:

I think some will disagree to part of the conclusion here. 

One expert, Bill Whitlock has a different viewpoint. While other experts think that sometimes both ends and sometimes send end only (with a hybrid at the receive end) is best.

 

On 8/4/2017 at 1:08 PM, R1200CL said:

"......Ground loop currents are not a real problem for correctly-designed pro-audio equipment, in fact they are a real benefit......)

Very true. It's not the multiple ground paths that's the problem, it's the loop area.

 

[R1200CL]

With Metz plugs.

 

Expext the plugs to be isolated from the Faraday Cage. 

 

 

[agladstone]

Thanks! It looks like a nice Ethernet cable! 

[Cornan]

Here is my initial impressions of the Ghent Audio ET02 Ethernet cable.

I ordered a 15cm and a 50cm cable.

 

As you can see it is growing on me and I can without a doubt say that it is the best Ethernet cable I have tried in my setup up to date. Strongly recommended! ?

[asdf1000]

7 hours ago, Cornan said:

 

As you can see it is growing on me and I can without a doubt say that it is the best Ethernet cable I have tried in my setup up to date. Strongly recommended! ?

Thanks for sharing Cornan.

 

Just to double check, the cable's shield is not connected to the connectors at all, at either end of the cable?

 

The shield is only connected to the 'external wire' that runs straight down the outer jacket?

 

 

[Cornan]

3 minutes ago, Em2016 said:

Thanks for sharing Cornan.

 

Just to double check, the cable's shield is not connected to the connectors at all, at either end of the cable?

 

The shield is only connected to the 'external wire' that runs straight down the outer jacket?

 

 

 

Your welcome Em2106! ? Yes, correct on both questions. The shield is not connected to the plugs and it uses the JSSG loop with external drain wire. Awesome quality cable that sound inferior to other ones I've tried. Still expecting it to improve some more.

[tboooe]

22 minutes ago, Cornan said:

 

Your welcome Em2106! ? Yes, correct on both questions. The shield is not connected to the plugs and it uses the JSSG loop with external drain wire. Awesome quality cable that sound inferior to other ones I've tried. Still expecting it to improve some more.

Are their any special instructions that we need to provide Ghent when ordering?

 

Also, are you saying this cable does NOT sound as good as others you have tried?  I thought you liked it?

[Cornan]

37 minutes ago, tboooe said:

Are their any special instructions that we need to provide Ghent when ordering?

 

Also, are you saying this cable does NOT sound as good as others you have tried?  I thought you liked it?

 

I love the Ghent ET02! I did'nt notice there sneaked in a NOT somewhere! ?

 

No special instructions to order. I choosed T568B. No shield attached and JSSG loop is the normal ET02 cable. If you want special lenght that needs to be confirmed via e-mail to Ghent. 0,10-1 meter is the same price.

[tboooe]

8 hours ago, Cornan said:

 

I love the Ghent ET02! I did'nt notice there sneaked in a NOT somewhere! ?

 

No special instructions to order. I choosed T568B. No shield attached and JSSG loop is the normal ET02 cable. If you want special lenght that needs to be confirmed via e-mail to Ghent. 0,10-1 meter is the same price.

Ok thank you. I  will give it a try.  What is the difference between T568A and T568B?

 

BTW, here is the part of your post that confused me "Awesome quality cable that sound inferior to other ones I've tried."  So to be clear, you think this Ghent cable sound better?

 

 

[R1200CL]

36 minutes ago, tboooe said:

What is the difference between T568A and T568B?

 

It's how it's terminated. 

If you google you will get a petty good explanation. 

 

Anyway just choise T568B. 

 

You should wonder more about which plug to choose ?

Though I can't give you a good advice, and that everything points against German quality, I can't see what's wrong with the Chinese option offerd.

 

Don't go below one meter. And don't ask me why. The advice was given to me by the Norwegian Belden dealer. 

 

Ghent will be offering the 90 degree Metz plugs as well. 

They will most likely  be to big if you want to use with an UltraRendu with a USPCB into something.

But my guess is that a small USB extension in conjunction with the USPCB. 

It's only about a centimeter. 

 

https://www.elfadistrelec.no/Web/Downloads/07/98/130E405042-E_EN.pdf

 

[Cornan]

1 hour ago, tboooe said:

BTW, here is the part of your post that confused me "Awesome quality cable that sound inferior to other ones I've tried."  So to be clear, you think this Ghent cable sound better?

 

That would be superior translated by my Android to inferior without me noticing. It should be Superior and nothing else! ?

[Cornan]

Here is further impressions of my 15cm & 50cm Ghent Audio ET02s for those who are interested.

 

 

[Audiophile Neuroscience]

Hi All,

Thank you JohnS for your post on star-quad cables for DC power connections !

 

Can star-quad be used to power ssd's (eg from an LPS1)?

 

If so, AFAIK there are only DIY cables to implement this by modifying a  Molex to SATA power connector and presumably with cheap, thin wire.

 

Has anyone done a  starquad DC > SATA power cable or obtained a ready made cable from Ghent (with or without JSSG) ?

Cheers

David

[Ryelands]

Has anyone done a  starquad DC > SATA power cable . . .

 

Yes. I use an LPS-1 set to 5v to power an SSD, an Intona and a USB>I2S card. I hand-wound a wiring harness from 24 awg cables with quad-core geometry and shielded it with self-adhesive copper tape wired JSSG-style. I used a scrap  connector for the SSD. (As a precaution, I did try separately powering the SSD in case sharing the PSU affected the sound quality of the other devices but it didn't seem to.)

 

I also shielded the SSD and its data lead with self-adhesive copper sheet and configured them as another Faraday shield. I can't really say how much difference that made as I've now configured every digital device in my system as Faraday shields and, for obvious reasons, did so to several at a time. What I can say is that the improvement overall was dramatic and well worth the effort.

 

HTH

 

[Audiophile Neuroscience]

12 hours ago, Ryelands said:

Has anyone done a  starquad DC > SATA power cable . . .

 

Yes. I use an LPS-1 set to 5v to power an SSD, an Intona and a USB>I2S card. I hand-wound a wiring harness from 24 awg cables with quad-core geometry and shielded it with self-adhesive copper tape wired JSSG-style. I used a scrap  connector for the SSD. (As a precaution, I did try separately powering the SSD in case sharing the PSU affected the sound quality of the other devices but it didn't seem to.)

 

I also shielded the SSD and its data lead with self-adhesive copper sheet and configured them as another Faraday shield. I can't really say how much difference that made as I've now configured every digital device in my system as Faraday shields and, for obvious reasons, did so to several at a time. What I can say is that the improvement overall was dramatic and well worth the effort.

 

HTH

 

Thanks very much Ryelands.

I'm not an experienced DIYer. I dont suppose you might post a more step guide with some pics if and when you have time? I'm sure it would be also instructional to others. Perhaps even JohnS might comment.

Cheers

David

[alecm]

What about AC ? I mean, could i use starquad cable for AC transmission? 

[Cornan]

31 minutes ago, alecm said:

What about AC ? I mean, could i use starquad cable for AC transmission? 

 

Yes ofcourse you can! I can assure you that AC mains starquads is great (best IMHO)! ?

 

http://www.atlhifi.com/shop/audio-cables/1-meter-power-cable-silver-in-ptfe-rhodium-plated-schuko-and-iec-connectors/

 

BTW. I have also ordered this proper starquad USB cable (2x4 conductors) with dual shields and JSSG loop. Looking forward to give it a try within a couple of weeks or so! ?

 

 

 

[markvandepas]

Nice video from Benchmark about starquad aligned wires inside a microphone cable:

(also some nice demonstration on noise coming from switching-PSU's compared too a line-frequency transformer at 8:00 minutes and after)

 

Also a nice read from Belden on the effectiveness of shielding compared too starquad wire alignment inside a cable.

http://www.belden.com/blog/broadcastav/How-Starquad-Works.cfm

 

 

 

 

[Speedskater]

Many pros are now going to unshielded bonded-pair Cat7 for balanced interconnect cables.

[Alexandro]

LPS-1, UltraRendu and DC cable, If use Ethernet Cat6 UTP cable instead of Canare 4S6? In theory Cat6 UTP is better separated conductors and better retain geometry due to the cross partition between the pairs. On the section of the conductor, each pair is normally equal to 0.2 + 0.2 = 0.4mm2, and when two such pairs are joined, 0.8mm2 is obtained. What do you think?

[Speedskater]

Cat6 or Cat7 for a 4 channel balanced interconnect cable is fine, but for a current carrying DC cable not so much.

While Cat3 or Cat5 can mach a nice (and almost free) speaker cable, you have to parallel several cables.

[Forehaven]

Does anyone know how to make a star quad cable...is there a set number of twists per inch or something?

[Cornan]

28 minutes ago, Forehaven said:

Does anyone know how to make a star quad cable...is there a set number of twists per inch or something?

 

Easiest is to buy a couple of meters of Canare 4S6 http://www.ebay.com/itm/HIFI-Japan-Made-Canare-4S6-Copper-Speaker-Cable-Wire-DIY-4-0-51-Conductor/291934904144?ssPageName=STRK%3AMEBIDX%3AIT&var=590923122121&_trksid=p2060353.m1438.l2649 and screw terminal plugs http://www.ebay.com/itm/1pc-5-5x2-5mm-2-5mm-CCTV-DC-Power-Male-Plug-Free-Solder-Terminal-Screw-Connector-/321901337464?hash=item4af2d09b78:g:DeYAAOSwYHxWKeLj. Red & pink wired to positive and white & creme wired to negative.

 

 

 

https://en.wikipedia.org/wiki/Star_quad_cable

 

[Speedskater]

IF you

2 hours ago, Forehaven said:

Does anyone know how to make a star quad cable...is there a set number of twists per inch or something?

If you were making a balanced interconnect cable, it takes big expensive machines to make a good cable.

But for loudspeaker cables, AC power cables or DC power cables we don't need that sort of precision.

Any reasonable number of twists per foot for the cable you are using will work. Do it by eye, if it looks good, then it's OK.

(maybe 4 to 12 twists per foot).

[BigGuy]

On 5/4/2017 at 8:26 PM, JohnSwenson said:

OK here it is: cable shielding, how to make it work and how almost all cables have it wrong.

 

The first important question is, what is electrical shielding and how does it really work?

 

Lets look at the infamous "Faraday cage". For this discussion it is a metal box, with all sides well electrically connected (no gaps). Shielding means that electrical fields outside cannot be sensed inside. Conversely electrical fields inside cannot be sensed outside.

 

So how does this work? When an electric field from the outside world impinges on the box it causes the electrons in the metal to move, this rearrangement of the electrons creates an electric field inside the metal which exactly counteracts the external field, thus the field is essentially stopped at the periphery of the box.

 

The important aspect here is the part "electrons in the metal move". What are moving electrons called? Current. In order for current to flow there has to be a loop. Current will not flow unless there is a loop. In the case of the Faraday cage, the loop is the whole cage. Lets say an electric field impinges on a side of the box, this causes a current flow that goes all the way around the box back to where the field impinges on the box. If the sides are not electrically connected to each other the current cannot flow, thus the electrons cannot move, and the canceling electric field does not get setup, thus no shielding.

 

It turns out that for AC electric fields it is a little different. Some current can flow due to capacitances between conductors. The electrons can move a little bit one way, then a little bit back. If the frequency is high enough the back and forth movement, which is charging and discharging the capacitance is sufficient for shielding. For a given capacitance the lower the frequency the less effective the shielding. The electrons start moving which charges the capacitance, then stop moving when fully charged, they don't do the full movement necessary to produce the canceling field.

 

So what about shielded cables? I hope is now obvious that for shielding to be effective there needs to be a conductive path from one end of the shield to the other. If there is not such a path the only shielding that is going to happen is for high frequencies due to cpacitances involved with the shield.

 

The best way for the shielding to work properly is a separate wire connected to each end of the shield. This is sufficient for shielding from DC to very high frequencies. Note the shield does NOT have to be connected an earth ground, the "ground" of the circuit at either end, or any thing else for that matter. A cable with a shield the is not connected to anything else except itself (ie a separate wire from one end to the other of the shield) will be highly effective in shielding what is inside.

 

Where does this wire need to go? It can be either inside or outside the shield, but if it is inside it can couple to the signal wires inside, so it is usually best to have it outside the shield. Note it has to be insulated from the shield except for the ends where it connects to the shield. It should intersect as little of the external field as possible so it should NOT be tightly spiraled around the cable. Just running along side the shield is best, although a very loose spiral (say one turn per foot) is almost as good.

 

So some ramifications of this: The traditional "connect the shield to one end and let the other end float" is not good, it does not allow a loop so shielding does not happen very well. If you add the external wire connected to the shield at both ends, then you CAN connect one or both sides of the shield to the signal ground or some other ground, but you don't NEED to for effective shielding. You will find that in many cases leaving the shield completely disconnected from the rest of the circuit is the best way to go, you get the benefit of properly working shielding without any interaction of the shield with your system. You may wind wind up with static charges on the shielding so a resistance from the shield to ground may be useful in some cases in order to dissipate static charges.

 

So how come nobody does this? I don't know. My only guess is that cable shielding has been going on long before the actual mechanism for shielding was worked out, thus by the time it was understood, cable shielding was "standard" and nobody ever even thought about analyzing it based on an understanding of how shielding actually works.

 

But shouldn't the big companies know about this? It seems they don't. I have read several app notes from Belden that state that shielding is only effective at high frequencies, at audio frequencies and power supply frequencies (60Hz etc) it is totally ineffective.

 

Audio people are the only ones that seems to at least empirically know about this. Remember phono cartridges and preamps, there is a little green wire that goes from the "ground jack" on the preamp to the tonearm. Everybody assumes that this is to "ground the cartridge" but what it really does is provide a loop from one end of the interconnect shield to the other, it has nothing to do with whether it is "grounded" or not. So if you have (or had) a turntable you were actually taking advantage of this without realizing it.

 

So there you have it, shielding DOES work, but only if you provide a path from one end of the shield to the other. This is effective even if you don't connect the shield to anything else.

 

John S.

 

 

 

 

 

 

Thank you, John.  This has got to be one of the best DIY improvement posts and one I will be trying.

 

A couple of questions...

 

For John:  Given the thread topic, the JSSG has great applicability to DC power cables.  Does it also offer value for other cables, e.g., USB, interconnects, AC power cables, etc., and, if so, how would they rank?

Which would be better...tinned or copper braid?

 

For anyone:  Can anyone provide sources of braided shield here in USA that people have done business with?

I bought some copper braid shield from a motorcycle shop some time ago intended not only for protecting but blinging-up gas line tubing.