DIY DC power cables

[Daudio]

10 minutes ago, Em2016 said:

I'm super interested in how you go with your BJC Cat 6a cable for your client. Is it just this straight external wire modification that you are doing or any other modification?

 

My client has a 'hot-rodded' (by me) Mac Mini, which is blowing him away with just iTunes and ?? USB cable. He wants to try connecting into the Ethernet post in his PSA DAC Bridge II card. I offered my BJC CAT6a, but his 'PC support' guy has a ?? crossover cable. Then I picked up a nice 10' GigaWare CAT5e crossover for $2 at a Radio Shack Going-Out-Of-Business-For Real-This-Time sale !

 

Not sure where this is going yet... Would be nice to experiment with diff. cables, but the only way to use the PSA Bridge card is with DLNA. The only software that my guy is willing to deal with, and supports DLNA, is JRiver Media Center. I installed it and have it sharing a library with iTunes, both have extensive playlists and views... (oops got off track) The problem is that JRMC sounds crappy  The client has a great ear, and he picked up on that real fast. That is not going to help evaluating Ethernet vs USB, much less different cables. I want him to try Audirvana+, but that will have to be at his pace.

 

So, I'll try and remember to let you know when/if anything happens along the lines of your interest. Good night...

 

[JohnSwenson]

To clarify, an Ethernet cable which connects the shield through the connectors into the boxes at both ends can lead to leakage loops between computers/network equipment and your streamer/DAC. The BJC CAT6A cable even though it has a shield does not do this, the shield does not connect to the boxes at either end.

 

The "end to end external wire" is my approach of adding an extra wire connecting both ends of the shield. The approach has nothing to do with whether the shields are connected to anything else at the ends. If the ends of the shield are connected to something else which makes a connection between ends (say a ground wire) then the wire you add may make little difference.

 

If the shield ends are not connected to anything (such as the BJC CAT6A) then adding the external wire will not change that, thus preventing a leakage loop. If the shield ends ARE connected to the devices then a leakage loop can form, the external wire does not change this.

 

John S.

 

 

[asdf1000]

18 minutes ago, JohnSwenson said:

If the shield ends are not connected to anything (such as the BJC CAT6A) then adding the external wire will not change that, thus preventing a leakage loop. If the shield ends ARE connected to the devices then a leakage loop can form, the external wire does not change this.

 

Thanks heaps John, I thought this was the case but in your previous reply I didn't see any mention of the BJC Cat6a (or other similar where the shield ends aren't connected to anything else). Crystal clear now.

 

I haven't seen any Cat7 or Cat8 shielded ethernet cables where the shields are NOT connected to anything else (they could be out there), so I will stick with the BJC Cat6a for your external wire mod. The BJC is very reasonable priced and well made too.

[jaaptina]

I just assembled an ethernet cable consisting of a ViaBlue cable and Telegärtner connectors. Those metal connector housings are meant to be connected to the cable shield. Should I try to isolate the cable shield from the connector housings? 

[R1200CL]

[R1200CL]

The above plug is what currently is planned used by Ghent as cat 7 with JSSG added. 

 

It it is not Telegärtner. As you can see the individual connector does not have shielding in plug. 

 

I was was thinking to first connect the shield to the plug according to cat 7 spec.

If there is a demand to also produce a JSSG cable without the shield connected to the plug, I suppose those like to order, email him. 

Based on demand, I think both versions may be available for purchase. 

 

This may also require some testing in order to conclude which one is best. Which probably in any case will vary depending on your setup. 

 

I suggest those that have good enough ears and gear can maybe ask for a sample from Ghent (and order one in addition)

I personally like to test with only the 10/100 pairs connected. 

 

I will use my BJ to compare with. I believe much of the secret with Ethernet cables lies in the plug. 

 

For the ground loops, I actually don't care. There will be a MicroRendu powered by an LPS-1 in one end, and a old 10/100 switch also powered by a LPS-1 in the other end. 

So at least in my case the LPS-1 should prevent any ground loops. 

(Also my old D-link has plastic housing, it that matters shield vise)

 

What I'm not 100% sure about is if I possibly can have a ground loop to the next switch if I'm using a similar cable. Maybe John can tell. 

 

In any case, that can be blocked by a BJ 6a cable. I don't see the need of a JSSG on that cable, as the signal get reclocked in the last switch as well in the MicroRendu ( or the ISO Regen in addition). 

 

So I'm thinking the Cat 7 JSSG (John Swenson Shield Guidline) is only needed in the last end / cable in the chain. 

[asdf1000]

On 6/8/2017 at 1:58 AM, R1200CL said:

I got my "JSSG" USB cable today. 

One week from order to deliver. Impressive ?

 

And the cable looks looks very nice. The shield return cable is covered by a cohere by a transparent " tube". 

 

Time to test.

 

How did it sound ! :-)

 

Can you share some more pics of the cable overall.

 

Is he planning to add these modified cables to his website?

 

Cheers

[R1200CL]

7 minutes ago, Em2016 said:

 

How did it sound ! :-)

 

Can you share some more pics of the cable overall.

 

Is he planning to add these modified cables to his website?

 

Cheers

 

I will do more pictures later. I exchanged it with a AQ Coffee. It was definitely not worse  ? . 

 

Ghent is evaluating to list it on his website. However, just email him and order one. It's an affordable cable. 

I think you probably can use present web format and order. I did. And then email you like the JSSG version. 

[Daudio]

2 hours ago, R1200CL said:

with JSSG added. 

 

And so, I think "JSSG" WTF ??

 

2 hours ago, R1200CL said:

the Cat 7 JSSG (John Swenson Shield Guidline)

 

Then, only in the very last line of your post, do you reveal the meaning of your acronym ! (usually that is supposed to come first...)

 

But then I beat you to the punch with my "Shorted Cable Shield (SCS ?)" in an earlier post

 

BUT ! Neither of us has the right to name @JohnSwenson's idea. That is clearly his prerogative.

 

The idea definitely needs a name ! At least, so that all the lazy audiophiles only have to type a few capital letters, and also so there will be one less of the many thousands of ways for us to miscommunicate 

 

So what say you John ? Do you have a name you like, or either of our suggestions ?

You know that nature abhors a vacuum, so there will be names applied to your idea, but as the 'inventor' I would prefer that you do the naming 

 

[asdf1000]

I actually recently asked a well known cable maker about this type of design and they said they had considered this design some years ago but mentioned their own cable and shielding design (which doesn't have an external wire) resulted in a "slightly" (their words, not mine) better SNR in testing. I have to trust their word on that but you never know.

 

But the price difference between their cable and the Belden 1840A John recommended me (nearly 50x !!) was a no-brainer (easy decision) for me to go with the Belden 1840A cable with external end to end wire, for a "slightly" worse SNR (if that's true)...

 

I should have those Belden 1840A XLR's soon! Can't wait.

 

[R1200CL]

3 hours ago, Daudio said:

The idea definitely needs a name !

 

Not that it matters to me, but I've used that JSSG since he wrote the guideline. 

[JohnSwenson]

8 hours ago, R1200CL said:

The above plug is what currently is planned used by Ghent as cat 7 with JSSG added. 

 

It it is not Telegärtner. As you can see the individual connector does not have shielding in plug. 

 

I was was thinking to first connect the shield to the plug according to cat 7 spec.

If there is a demand to also produce a JSSG cable without the shield connected to the plug, I suppose those like to order, email him. 

Based on demand, I think both versions may be available for purchase. 

 

This may also require some testing in order to conclude which one is best. Which probably in any case will vary depending on your setup. 

 

I suggest those that have good enough ears and gear can maybe ask for a sample from Ghent (and order one in addition)

I personally like to test with only the 10/100 pairs connected. 

 

I will use my BJ to compare with. I believe much of the secret with Ethernet cables lies in the plug. 

 

For the ground loops, I actually don't care. There will be a MicroRendu powered by an LPS-1 in one end, and a old 10/100 switch also powered by a LPS-1 in the other end. 

So at least in my case the LPS-1 should prevent any ground loops. 

(Also my old D-link has plastic housing, it that matters shield vise)

 

What I'm not 100% sure about is if I possibly can have a ground loop to the next switch if I'm using a similar cable. Maybe John can tell. 

 

In any case, that can be blocked by a BJ 6a cable. I don't see the need of a JSSG on that cable, as the signal get reclocked in the last switch as well in the MicroRendu ( or the ISO Regen in addition). 

 

So I'm thinking the Cat 7 JSSG (John Swenson Shield Guidline) is only needed in the last end / cable in the chain. 

An LPS-1 does NOT prevent leakage loops if you have cables that connect the shield to the jack. If the cables don't connect the shield then the internal transformers prevent leakage loops from the network equipment and the LPS-1 prevents a loop from the power to the microRendu.

 

The external wire on the BJC CAT6A cable properly shields it and prevents external interference of the cable so it can still be useful.

 

John S.

[R1200CL]

On 15.6.2017 at 6:13 AM, JohnSwenson said:

To clarify, an Ethernet cable which connects the shield through the connectors into the boxes at both ends can lead to leakage loops between computers/network equipment and your streamer/DAC.

 

CAN ?

 

Is this because the metal RJ45 interface female connector on the print normally is connected to ground ?

 

So it depends on your switch. And by using a ohm meter you can check if the connector is grounded or not maybe ?

 

Do you think using a dual star quad design where you only utilize the 10/100 will make any sense ? Which would probably mean using a cable not meant for Ethernet. 

 

How will your switch be designed to prevent ground loops ?

[asdf1000]

53 minutes ago, R1200CL said:

Do you think using a dual star quad design where you only utilize the 10/100 will make any sense ?

 

What's the correct way to do a starquad arrangement with ethernet cables? Is there a correct way? 

 

Cheers

 

[JohnSwenson]

5 hours ago, Em2016 said:

 

What's the correct way to do a starquad arrangement with ethernet cables? Is there a correct way? 

 

Cheers

 

Don't even think about starquad and Ethernet. High frequency stuff is quite complicated to get right, I would just let the cable experts do it. The only possible thing I would consider is the shielding with an external wire and don't use the connectors that connect shield, thus preventing leakage loops and having good shielding.

 

John S.

[asdf1000]

6 hours ago, JohnSwenson said:

Don't even think about starquad and Ethernet. High frequency stuff is quite complicated to get right, I would just let the cable experts do it. The only possible thing I would consider is the shielding with an external wire and don't use the connectors that connect shield, thus preventing leakage loops and having good shielding.

 

John S.

 

Thanks John. I thought Belden knew a thing or two about making ethernet cables! Thanks for clarifying, for all.

 

On the BJC Cat6a , BJC noted to be careful with soldering to the shield as "the iron may damage the insulation next to the particular pair that happens to be closest to the heat source, and in turn it will change the bonded & twisted pair geometry, causing that pair to fall out of spec and not pass certification."

 

For those of us not so skilled with the soldering iron (ME) it's just something to maybe consider 

 

[R1200CL]

On 15.6.2017 at 1:33 PM, Em2016 said:

Is he planning to add these modified cables to his website?

 

http://www.ghentaudio.com/part/u01(jssg).html

 

Several new cables added. 

[Middy]

The Swenson special is now official .

 

 @R1200CL Good work my friend...

[Middy]

I now realised I made a mistake.

My Modded LPS and IFI DC IPURIFIER Mod cable was selling it self short by me using a 2.1G  connector 2.1mm Hot pin....to a cheap 3 inch female to male 2.5mm hot pin adapter. Well I had a spare from the LPS1 cable.

Now it has a direct connection into my Brooklyn Amp with its shiney new Oyaide connector. Plus now I can do a decent job of wiring soldering them.

An off cut of the canare Sleeving makes a nice spacer/ insulation between hot neutral.

The sound difference between old and new is not subtle. Getting rid of a little adapter has made my day.... 

 

I am glad I went to the extra effort.

Have fun gents.

Dave

[asdf1000]

On 5/30/2017 at 2:51 PM, JohnSwenson said:

#3:

Yes, solder the external wire to the shield at each end. Connect to pin 1 at both ends for XLR. SOME configurations may not need the pin 1 connection, but assume you need it to begin with.

 

Hey John @JohnSwenson

 

Could you kindly elaborate more on this, as in examples of configurations that may not need the XLR pin 1 connection?

 

Would an example be where you have both the DAC and the Amp, both with a fully balanced topology? And in this case the external wire isn't needed? Or is there still benefit.

 

Appreciated in advance, Sean

 

[Speedskater]

There are some situations where the XLR balanced interconnect shield is not connected at the receive end.

Situations like running the cable from one building to another. Where a lot of AC power current might flow  thru the shield.

In this case a hybrid connection is used. That's a small cap from the shield to connector.

I still don't get this external wire idea, unless it's about common impedance coupling.

[jamesg11]

Is that 'external wire' the same concept as on my Curious usb cables?

[asdf1000]

49 minutes ago, jamesg11 said:

Is that 'external wire' the same concept as on my Curious usb cables?

 

Hi Jim, I think the Curious USB cable external wire is different, but could easily be wrong (as usual)

 

Explained here: http://www.6moons.com/audioreviews2/curious/3.html

 

"Once I settled on the conductors—high purity silver—it was on to the insulation materials. And so on. I then moved to the 5V power leg and onto the ground leg. Testing a huge range of conductors and materials, two interesting factors arose. 1/ shielding.  A lot of manufacturers go to extraordinary lengths to shield their data lines. In the main, this is done to prevent radiated noise from the 5V power leg and the ground leg from interfering with the data lines. Plus, we have EMI and RFI from the environment that may cause upset. However, all the shielding I tested produced an inferior sound. The cure was worse than the malady. How to solve this problem?  Instead of shielding the data lines, I decided to shield the 5V power leg (and remove it from the vicinity) and shield the ground. I then let the USB receiver chip do the rest. As you know, data via USB is carried as a differential signal. A mirror image of the signal travels down each data leg and is summed at the receiver chip, effectively removing noise. In this respect, the USB cable design is very similar to an analog balanced cable. 2/ the ground leg. The physical and electrical relationship between data lines and ground is extremely important. A lot of time went into this part of the design. Bottom line, the Curious was developed from the ground up based on listening tests at each step. The objective was to unlock the purity and dimensionality that digital files are capable of providing."

[Speedskater]

The 6moons writers are all poets, artists or dreamers, so don't put much stock in anything technical that they write.

 

When things sound different that shouldn't sound different, you don't just jump to the conclusion the A is better than B. Sounding different is only the first step. You need to investigate why they sound different. It could be an uncontrolled variable or a situation specific problem.

[asdf1000]

7 minutes ago, Speedskater said:

The 6moons writers are all poets, artists or dreamers, so don't put much stock in anything technical that they write.

 

When things sound different that shouldn't sound different, you don't just jump to the conclusion the A is better than B. Sounding different is only the first step. You need to investigate why they sound different. It could be an uncontrolled variable or a situation specific problem.

 

The part quoted above is a quote from Curious though.