Hi Guys !
Thanks a lot to All for the extremely valuable advice.
just one question left on the topic.
Can we agree that any negative issue in the usb signal transfer should result in some sort of distortion and then it should show up in a distortion measurement ?
Moreover .... may I consider the THD+Noise measurement the king of all the measurements ?
By the way, what I am seeing on my interface makes me cry ... 🙁
what a **** of units indeed.
Thanks a lot again, gino
Thanks a lot to All for the extremely valuable advice.
just one question left on the topic.
Can we agree that any negative issue in the usb signal transfer should result in some sort of distortion and then it should show up in a distortion measurement ?
Moreover .... may I consider the THD+Noise measurement the king of all the measurements ?
By the way, what I am seeing on my interface makes me cry ... 🙁
what a **** of units indeed.
Thanks a lot again, gino
No.
It should be seen as drop outs of the signal. And maybe there is a way to interogate the error correction to see how hard that is working.
distortion is an analogue thing. USB is digital data.
Hi thanks a lot for the helpful reply.
Then I give up. Too much complex issue.
Even just a basic THD+Noise measurements is quite a task for me.
I will go on with listening just hoping to find a pleasant result.
I am done.
Thanks a lot again, gino
No, it's actually an extremely simple issue. USB works exactly as designed for billions of computers with many billions of peripherals. This is a complete non-problem, for which hucksters and ignoramuses are happy to sell you a solution.😀
If there exists a audible problem due to the gnd-connection via USB cable , the only promising solution is an USB-isolator imho.
Not All USB Cables Are Equal...
There is variation in USB cable assemblies....ie copper or more correctly lack thereof.
The typical Ebay el-cheapo usb cables as supplied with typical Ebay el-cheapo usb devices are built with as little copper as is possible.
If all cables available really did meet usb.org specs there would be no problems.....I have already related that a pocket 3.5" usb hard drive will not work with a particular usb extension cable that I have.
I am experimenting with usb cable filters and I am getting interesting results.
Dan.
Not so fast.
There is variation in USB cable assemblies....ie copper or more correctly lack thereof.
The typical Ebay el-cheapo usb cables as supplied with typical Ebay el-cheapo usb devices are built with as little copper as is possible.
If all cables available really did meet usb.org specs there would be no problems.....I have already related that a pocket 3.5" usb hard drive will not work with a particular usb extension cable that I have.
I am experimenting with usb cable filters and I am getting interesting results.
Dan.
Like I mentioned before, I found one defective USB cable myself. I spent $5 and got a new one. Fixed the problem.
Seriously, this is a subject left to hucksters and ignoramuses.
Seriously, this is a subject left to hucksters and ignoramuses.
Yes.
I am running a USB signal isolator/power injector (12V battery) board and I find subjectively (sighted) that this is a useful improvement in clarity and image size/placement.
Interestingly/annoyingly, I find that using a USB Type A to Type B adaptor directly between the Isolator pcb and DAC usb input is subjectively preferable (as described above) to a standard 1m Type A to Type B usb cable (printer cable) connecting Isolator pcb to Dac usb input.
Dan.
Hi ! ok issue closed. I will just experiment some usb isolators.
I bought them and never really used.
Thanks again.
Hi and thanks for the advice.
I will try some i have at hands (if i find them i do not remember where i put them). They are based on the Adum chip.
Some disc drives take more current than the USB spec, and hence need low resistance cables. The fault lies with the drives, not the compliant cables which may have higher resistance than the drives need. Irrelevant for audio. Some disc drives (or their controllers) don't negotiate the current but just take it - non-compliant, but not the cable's fault.
I think you where looking for ".. that may effect the receiving circuit." as most probably there where no faults seen at application protocol level.
//
Seems silly to me, better to have a decent return path.
As to ground noise anyone measured it, or just tried filtering it with a ferrite instead of compromising signal integrity by removing the ground connection and forcing currents to take paths you have no control over...
Yes, it is, but USB noise injects itself into the analog circuits.
Proof is what I said earlier in this thread, that a USB isolator gave much worse measurements. More proof is that the Jitterbug improves sound quality in an immediate and significant way.
Putting a Jitterbug in line with "Plate Goodbye Noises USB stabilizer" measures worse than just a Jitterbug or stabilizer. I imagine there is some kind of resonance that develops.
I suspect that the culprit is noise on the ground, but it might not be. Could be why people use the "battery ground tweak"
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Miniscule or no difference in measurements.
Just my ears and one other person's. And reviewers seem to like it.
I went in to trying it literally calling it "snake oil." And have you ever gone to AB-ing something and the difference was so big that you didn't even need to AB? That's what it was.
Just my ears and one other person's. And reviewers seem to like it.
I went in to trying it literally calling it "snake oil." And have you ever gone to AB-ing something and the difference was so big that you didn't even need to AB? That's what it was.
Yawn, provide some hard data instead on anecdotal evidence... What kind of isolatotor galvanic, not going to isolate noise unless done right and most audiophile ones pay no homage to routing and isolation for high frequency digital noise.... I have to do this in the real world without magical components etc.
LOL the jitterbug is a joke, no noise isolation what so ever, its a crappy layout and in my world would be rejected as the work of an incompetent amateur, the noise couples straight across the layout, see the jitterbug thread if you want to learn more.
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