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Review and Measurements of Wireworld Starlight 7 USB Cable

KSTR

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#61
Nice results, interesting stuff.

Looking at the pure symptoms, I think we're looking at a signal integrity problem: GND polluted by shared balancing currents, right in the analog section, including the outgoing RCA cables.
And changing the USB cable modifies those paths and/or the amount of leakage currents.

If I got Amir's setup correctly, his source feed to the USB cable has USB-GND bonded to PE (desktop PC) and the analyzer has its GND at PE too, right? Those PE potentials are dirty and low impedance, giving rise to large balancing currents on the USB shield, across the DAC's PCB (disturbing GND references) then into the RCA shields which terminate to PE of the AP. Changing the USB cable changes the impedance and hence details of the current flow, R*i and L*di/dt errors along the shared GND path will vary accordingly. On top of that we have the mains leakage from the Class-II SMPS wallwart which also returns to the mains via PE and now has two paths available... then again his earlier measurement with a floating source showed less if any leakage than this new measurement, that why I think the PE-to-PE connection dominates the noise picture.

To test the hypothesis the DAC could be fed via TOSLINK for galavanic isolation and then the original balancing current could be re-introduced by using the USB cable's shield for a point-2-point GND-only connect from source to destination USB-Sockets (soldering the connectors together with short wire stubs would be best, but I see the problem...). TOSLINK alone should give a clean spectrum (like in the earlier measurement) but with the GND connection re-introduced I would hope to see siginificant rise in leakage similar to that when the cable did actual data transfer as well. If switching over to the other cable mis-used as a "GND-bleed" the same way again produced a result similar to its actual use-case then we've got it, a classic "ground loop" scenario. If so, the proper solution should be breaking the loop, preferably at the source side.
 
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#62
Even at $100, I question the validity of having a USB cable cost this much. It's digital. Digital is error corrected as we know. As long as quality is there to reduced errors and it's designed within the USB specification, it'll do its job... The crazy thing behind this is that the receiving connectors on each side of the cable are cheap, tin-plated connectors mated to more often than not, cheap solder and 2-layer PCB's!!! (the computer side).

Look at the prices many of these companies charging ripping people off:
https://www.thecableco.com/cables/usb-cable.html?dir=desc&order=price

I've always questioned the "power cable makes your system sound exponentially better" line and settled on Canare 4S11 for speaker wire over hyper expensive Cardas, Audience, Shunyata, Kimber, etc. speaker wire, but a USB cable over $50 is just crazy. Just go read papers by Nelson Pass or Roger Russell...

“It's easier to fool people than to convince them that they have been fooled.” - Mark Twain
 

Jimster480

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#63
I would wonder how this performs vs a premium cable... the amazon cables I have found to be very hit and miss.
 

MZKM

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#64
Even at $100, I question the validity of having a USB cable cost this much. It's digital. Digital is error corrected as we know. As long as quality is there to reduced errors and it's designed within the USB specification, it'll do its job... The crazy thing behind this is that the receiving connectors on each side of the cable are cheap, tin-plated connectors mated to more often than not, cheap solder and 2-layer PCB's!!! (the computer side).

Look at the prices many of these companies charging ripping people off:
https://www.thecableco.com/cables/usb-cable.html?dir=desc&order=price

I've always questioned the "power cable makes your system sound exponentially better" line and settled on Canare 4S11 for speaker wire over hyper expensive Cardas, Audience, Shunyata, Kimber, etc. speaker wire, but a USB cable over $50 is just crazy. Just go read papers by Nelson Pass or Roger Russell...

“It's easier to fool people than to convince them that they have been fooled.” - Mark Twain
One of the funniest things I’ve seen were people recommending a ball bearing isolation product (the wooden blocks it comes with has a concave impression for the bearing to roll within), and not only did they claim less noise for sound systems, it also advertises clearer picture from video players.
 
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amirm

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#65
I would wonder how this performs vs a premium cable... the amazon cables I have found to be very hit and miss.
What premium cable are you suggesting?
 

NTomokawa

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#66
So the lesson here is... proper shielding?

Also, might I recommend that Amir write a disclaimer of sorts on top of the review, lest "Wireworld" links to this review and spins it along the lines of Measurements CONFIRM our cables work!!!!1!
 
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Tene

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#67
Maybe not since both data and power wires will have one common shield, but probably one can just buy the usb connectors and a few meters of good two wire shielded cable so data and power will have independent shielding, probably this will have the same benefits (if any of them are audible at all) than the cable reviewed.

Edit: it seems that someone has already thought about it, this cable already has double/triple shielding under one sleeve:

https://www.audiophonics.fr/en/digi...le-shielded-silver-plated-o-72mm-p-11077.html
Yeah, seems like the brand of the cable is Aucharm, bumped into the exact same one on Aliexpress:
https://www.aliexpress.com/item/4-c...ree-copper-shielded-net-FOIL/32806356588.html

Some USB A to B cables are based on it and are branded Aucharm as well:
https://www.aliexpress.com/store/pr...i-DAC-Amplifier-0-5m/1799190_32769704881.html

Though if you only want to isolate data and power, wouldn't a design like this be enough?
https://www.aliexpress.com/item/HIF...USB-DAC-Cable-HIFI-USB-cable/32786167837.html
 

KSTR

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#68
So the lesson here is... proper shielding?
No, the lesson is that when measuring sub-microvolt noise you need to have full control of the setup, notably the balancing current paths. Ground loops to be identified and avoided, otherwise misleading results will happen.
The lower noise levels are not because that cable is intrinsically "better". It just happens to give a better result in this use case which is an illegal one, IMHO
 

Snafu

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#69
@Tene
I have been buying chinese cables lately and i have to say quality/price has been excellent. Latest purchase was rca-cables for D50, ~20€.
Plugs fit tight and construction feels solid. Correct length power cables ( 2 cables under 50€ incl s&h :oops: ) have been as good as any "high end"-label product.

kiina rca.jpg kiinavirtajohdot.jpg

edit [/off topic]
 

Blumlein 88

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#70
One of the funnies things I’ve seen were people recommending a ball bearing isolation product (the wooden blocks it comes with has a concave impression for the bearing to roll within), and not only did they claim less noise for sound systems, it also advertises clearer picture from video players.
Those actually do provide isolation from horizontal movement or vibration. Now whether this vibration reduction reduces noise or clears up video is another question.

A friction pendulum is similar and used to protect buildings from earthquakes and to prevent vibration from reaching sensitive equipment on smaller scales.

https://www.earthquakeprotection.com/single-pendulum

1549614705729.png


Good video to see demo of how effective they can be.
 
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Arnandsway

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#71
@Tene
I have been buying chinese cables lately and i have to say quality/price has been excellent. Latest purchase was rca-cables for D50, ~20€.
Plugs fit tight and construction feels solid. Correct length power cables ( 2 cables under 50€ incl s&h :oops: ) have been as good as any "high end"-label product.

View attachment 21552 View attachment 21553

edit [/off topic]
These white ones look funky! Almost like a snake. Snake oil before making oil out of it? :D
 

MZKM

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#72
Those actually do provide isolation from horizontal movement or vibration. Now whether this vibration reduction reduces noise or clears up video is another question.

A friction pendulum is similar and used to protect buildings from earthquakes and to prevent vibration from reaching sensitive equipment on smaller scales.

https://www.earthquakeprotection.com/single-pendulum

View attachment 21554

Good video to see demo of how effective they can be.
Correct, I belive they do work in isolating horizontal vibrations; but >$400 is a bit rich. The improvements to video is something I can’t see, not unless you are talking extreme amounts of vibration. Also, CD’s have skip protection and know when they aren’t reading correctly, so I also don’t see a benefit there, which the site claims.
 
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#74
One of the funnies things I’ve seen were people recommending a ball bearing isolation product (the wooden blocks it comes with has a concave impression for the bearing to roll within), and not only did they claim less noise for sound systems, it also advertises clearer picture from video players.
I tell ya, I've seen some crazy stuff - even bought much of it myself. I was outlining my CD's with sharpies back in the 90's. Had the crazy plinths with spikes on tripods, the separators for the $500 set of RCA's, the 2k speaker 8ft set of speaker wire... then, when selling a tube preamp to a guy, was over at his house and he had speaker wire elevated on glass things that looked from the Tesla era in his living room - it all clicked when I caught eyes with his wife - she looked over with a total shrug and eye roll - said it all...
 
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#75
Those actually do provide isolation from horizontal movement or vibration. Now whether this vibration reduction reduces noise or clears up video is another question.

A friction pendulum is similar and used to protect buildings from earthquakes and to prevent vibration from reaching sensitive equipment on smaller scales.

https://www.earthquakeprotection.com/single-pendulum

View attachment 21554

Good video to see demo of how effective they can be.
Yes, but it's all about where one's focus should be based on their "setup". In most cases, before spending money on special maple plinths, etc., people should be better educated or figure out how to better their room acoustics. I've been in many rooms with various levels of acoustical treatment and I know for a fact that I could, in general, make a Denon amp and pretty good speakers sound better than a system 20 times the cost in a typical living room. Now, that's a very general viewpoint, but maybe you can see my point. Stick a better system and it'll blow you away. I could take a Topping setup with Q Acoustics speakers or some consumer KEF's and make it sound fantastic. I'm a musician (not by trade) but have a friend who writes for TV shows like Dexter, etc. (old but it's the only one I can remember), he has Focal monitors in his studio. His setup sounds incredible. Sure, the speakers were expensive (3k) but the room is acoustically near perfect. Just thoughts...
 

JustIntonation

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#76
Perhaps this is the right place to ask the following related question.
For my laptop (HP ProBook 6570b) and my DAC (Anedio D2) using a 5 meter long USB cable (brand HQ) gives me severe constant dropouts.
I then used a 2 meter cable for a while without audible dropouts. But then when I used an external USB to S/PDIF converter with a short 0.4 meter USB cable the highest treble improved.
Now after I did some reading I don't think this is due to reduced jitter from the external USB interface. The internal USB interface of the D2 DAC is good enough and additionally the D2 DAC performs PLL jitter reduction which is shown and measured by them to be effective. Furthermore some calculating leads me to believe that total jitter less than roughly 20 us (microseconds) should be inaudible.

But I did read something else that interests me.
When the USB cable gets too long and we get audible dropouts, I read this means that packet loss is over 3%.
I further read that packet loss below 1% is inaudible. And read nothing about packet loss between 1% and 3%.
Before I was under the impression that if we don't get audible dropouts all is fine and bit perfect.
But now I'm not that sure anymore.. Can we get a degredation in quality before we get audible dropouts??
My question is for "asynchronous" USB interfaces.
If so, then perhaps chips used, drivers used, USB chip of the computer (read they differ in quality between manufacturers) and USB cable and cable length can all come into play..

And if not, then perhaps the double isolation from the USB data stream and USB power of my external USB-S/PDIF converter is what makes a difference.. Like the measurements show for the cables already. Perhaps the direct electrical connection of the computer to the D2 DAC was really bugging it to the point of degrading the treble. Have no measurements, but this doesn't seem that likely to me.. Perhaps I'll never know why.
 

Kyle / MrHeeHo

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#77
It has always irked me that cable companies focus on marketing their cables as something to improve performance when there are more concerning issues like durability. I can't tell you how many USB cables I've been through over the years :p
 

Veri

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#80
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