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USB cable makes a difference shock!

Thanks for the detailed maths on db ratio. I was aking what is happening in the digital to digital domain not in the analog result.

You clearly know nothing about digital then.

How's about you explaining why you think it will affect the digital domain rather than playing whataboutism?
 
OK digimastasensewaxonwaxoff... Youknoweverythingabouteverything, getya....

What has an inaudible analog converted result for to do with digital error?
 
Absolutely nothing which is why I said you clearly know nothing about digital.

My explanation also included the digital domain but as you clearly don't understand any of it you jumped on your high horse and started piffling on about analogue.

If you want to use a digital argument (which really doesn't apply in that test but we'll play along for shits and giggles)

USB 1.0 uses a signal differential of roughly 3v to represent a 1/0 therefore using a 3v reference -140dB would equal.....

0.000000000000003 Volts

or

0.3 pV

Even at the highest bandwidth and specific signalling USB 2.0 looks for a differential voltage of 400mV that is 0.4 Volts

Do you think that either 0.000000003 or 0.0000000004 mV could cause any spurious effects?

Once again explain why you think it will affect the digital domain?
 
So from what you've said above, you define all things digital as 'voltage' (and nothing to do with frequency)

Are you a specialist in the digital technology? or have you just bought a cheap second hand soap box??
 
In USB the digital signal is voltage, what do you think ditigal is then?
 
no its not...

USB is a high speed serial link (SERDES). The interface to the real world is in analog. For example, you will be needing equalizers, Clock and Data Recovery circuits etc., and they are in analog domain. Once the data is sampled, the processing is done in the digital domain.
 
Ahmed Noeman, System Engineer at Texas Instruments (2011-present)
Answered Jan 17, 2018


USB like many modern communication protocols is digital in nature. Data is logically structured in packets or frames composed of simple bits.

However this is how high level applications see the data, like an operating system writing to a USB port. the operating system is relying on a USB device driver to carry the data to the actual hardware which might be a USB chip.

The USB Hardware (the USB IC) will implement what is called the physical layer of the protocol, at that level (what is actually going to the data lines of the USB socket) everything is analog. The IC will convert the stream of bits into differential signal of few volts swing, will do some line encoding to ensure enough toggling of 0/1 is available, and some other functions.

Another task the USB IC might be doing (or may be another power chip) is generating the 5.0V for the USB devices to use as a power source, and limiting the current to a specified limit (0.5A or 1A). this is going also to the USB socket as power lines.

The USB receiver on the other side will extract the clock from the received data, and use it for bit detection. it will decode the encoded bits, and stuff the bits to send them back to the processing unit behind (which might be a processor or a controller). The clock recovery and data extraction are both analog in nature.
Other analog functions done by the receiver includes detecting some resistive elements to determine the unknown device speed before starting talking to it.

So in brief, when Ethernet, GSM, USB, PCI, VSDL and other protocols are said to be digital, it means they handle digital data in upper levels of network layers. The physical layer is always analog. This is even true for the memory bits carrying the binary data in your very digital computer.
 
You are googling for answers but understanding or interpreting the information correctly.

In USB the digital signal is voltage, what do you think ditigal is then?

The IC will convert the stream of bits into differential signal of few volts swing, will do some line encoding to ensure enough toggling of 0/1 is available, and some other functions.

USB could be viewed as a form of balanced line where it looks for a differential voltage to determine whether a binary 1 or 0 is being sent.

I've explained why I think it won't have any effects so I'll ask you once again, why do YOU think it will affect the digital domain?

(please don't google and post something something verbatum, explain your reasoning)
 
No I wasn’t googling for answers, rather I did some resource before comm eating in the first place. Not just making general statements or finish blanket answers, Rather trying to identify the nuances in the hope to understand why some claim there are differences and some like you reject the idea solely on principal.
 
Have you actually read and understood what the guy wrote!??? FFS don’t top and tail it to your own agenda. Read the whole fcuking thing, ideally with and open mind ...
 
@Cereal Killer -- I too think this is an interesting thread. I'm glad @Purité Audio posted it and that Amir at ASR did the measurements, which I have to admit were pretty unexpected. That said, my understanding of the situation here is that inaudible noise on the analog side is just that -- inaudible. Whereas if there were problems/corrupted packets on the digital side (for whatever reason, including some deleterious interaction between the "signal wires" and the 5V power line) then the problem would show up as easily heard -- and easily measurable -- dropouts, bleeps/blarps, what have you.
 
Yes i agree, but I'm trying to work out why people/manufacturers claim there to be differences (other than sales and marketing) and how they justify the use of different materials.
 
Mate, it's all just sales and marketing theres no reason behind any justification beyond basic shielding and reaching 5he certification spec.
 


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