Bits is bits?

[Miska]

High frequency DC is why I use ferrite beads on my DC cables...  

 

In fact the medical grade ~25 EUR Mean Well PSUs I use (5V DC, 6A) have both shielded cable and ferrite bead. Unlike the cheaper 10 EUR options...

[Miska]

2 hours ago, DonaldT2109 said:

This is where you are going completely wrong. This is where a lot of people have their huge, huge misunderstanding.

The analogue signal is not carrying any audio. The analogue signal is transporting the bitstream of digitally encoded audio

You cannot possibly affect the quality of the source audio by reducing distortion on the analogue signal. Can you really not understand this ?

 

There is some amount of misunderstanding here. We are talking about two separate things.

 

1) Correctness of data transfer

2) Noise injection to analog parts through galvanic connection of the source and DAC

 

(2) completely and independently bypasses the data path. It doesn't require any data to be transmitted and unless excessive, doesn't affect data transfer itself. But it tends to affect clocks, D/A conversion part and other analog parts of the DAC - this is where the crossing from digital to analog happens and this is where the electronics are sensitive to noises at levels down to -140 dB or so.

 

I've found audiophile USB cables to be usually non-spec compliant and cause more trouble than good. I personally use cables that are officially USB HiSpeed (USB2) or SuperSpeed (USB3) certified. But depending on DAC and many other factors, analog implementation of a digital USB source matters... This is one reason why I prefer Ethernet instead of USB, either in copper (transformer isolated) or optical form.

 

[marce]

1 hour ago, pkane2001 said:

 

“High frequency DC”! I’m glad we can still invent new things in a field that’s been studied and well documented for many decades

 

Read it on post #594 of this thread and another thread to do with USB cables...

[marce]

1 hour ago, Miska said:

High frequency DC is why I use ferrite beads on my DC cables...  

 

In fact the medical grade ~25 EUR Mean Well PSUs I use (5V DC, 6A) have both shielded cable and ferrite bead. Unlike the cheaper 10 EUR options...

#594 of this thread, its how USB works apparently.....

[DonaldT2109]

1 hour ago, Miska said:

There is some amount of misunderstanding here. We are talking about two separate things.

 

 

Some fascinating stuff Miska but I asked for just one thing

 

How does a USB cable change the sound of the audio that has been digitised like some people believe is possible.

 

No takers so far.   I wonder why?    

Perhaps they have all conceded that it is plain impossible

[marce]

1 hour ago, Miska said:

 

 

(2) completely and independently bypasses the data path. It doesn't require any data to be transmitted and unless excessive, doesn't affect data transfer itself. But it tends to affect clocks, D/A conversion part and other analog parts of the DAC - this is where the crossing from digital to analog happens and this is where the electronics are sensitive to noises at levels down to -140 dB or so.

 

 

And should be and can be covered during the design phase and layout... 

[marce]

2 minutes ago, DonaldT2109 said:

 

 

Some fascinating stuff Miska but I asked for just one thing

 

How does a USB cable change the sound of the audio that has been digitised like some people believe is possible.

 

No takers so far.   I wonder why?    

Perhaps they have all conceded that it is plain impossible

I have asked this question for years... Many years no answer, just random noise...

[DonaldT2109]

1 minute ago, marce said:

I have asked this question for years... Many years no answer, just random noise...

 

It started with a lot of people telling me that I am wrong. But after I started breaking down their illogical and flawed reasoning as well as their 'gifted amateur' explanations of how digital USB works,     it has all gone very quiet

 

I am actually waiting for another blast as I have a two questions. which together will absolutely prove the nonsense of these snake oil products

[kumakuma]

10 hours ago, fas42 said:

 

Nothing to do with errors, or what the digital signal looks like in analogue terms, as regards to processing in the digital domain .. this is all about electrical activity in some physical domain - unfortunately, electrical parts have no understanding that nearby electrical activity should be ignored just because it's called digital; separating a circuit board into two areas, and calling one side digital and the other analogue doesn't help one bit, even if you colour them differently, and draw lines marking the separation ... . Of course, some technical types do believe in this sort of magic, .

 

One can have a fun time with software tools like Spice, investigating what really happens in circuitry in real world situations. Then you can discover, for example, how amplifying circuits by even well regarded designers enter chaotic behaviour momentarily - the "assumed behaviour" is not the reality. Often, too much is automatically regarded as being fact, when careful examination reveals otherwise.

 

My approach in an ideal world would be to do a ridiculously OTT design and implementation exercise, so that I could be certain that there are no interaction effects. And listen. Then, steadily come back to the real world and build compromises on how the overall circuit was done. Until I could hear a difference. Then I would have a decent handle on what really matters, rather than living in a world of la la theoretical beliefs, .

 

[DonaldT2109]

LOL @ kumakuma

[marce]

50 minutes ago, DonaldT2109 said:

 

It started with a lot of people telling me that I am wrong. But after I started breaking down their illogical and flawed reasoning as well as their 'gifted amateur' explanations of how digital USB works,     it has all gone very quiet

 

I am actually waiting for another blast as I have a two questions. which together will absolutely prove the nonsense of these snake oil products

Looking forward to them.

[Miska]

1 hour ago, DonaldT2109 said:

How does a USB cable change the sound of the audio that has been digitised like some people believe is possible.

 

Well, with my Chord Mojo I had so many challenges finding USB cable that doesn't eventually end up with DAC blasting full volume white noise on my ears...  If you want to test USB cables and sources, that's a perfect product for the purpose. I guess that's why also HiFi-News is measuring USB source differences with it...

 

But various USB powered DACs are good candidates too. Like Meridian Explorer (2), and probably Audioquest DragonFly as well.

 

If there are differences, they are likely more due to point (2) in my earlier post, apart from the cases where there's a problem with (1), however symptoms are quite different.

 

 

My analog cables are primarily Supra, because the price is decent and I agree with their design philosophy. Plus they also have specs.

 

On digital cable front, I've been just trying to tell people NOT to use those damn shielded STP Ethernet cables in order to avoid totally screwing up the galvanic isolation Ethernet otherwise provides...

 

[DonaldT2109]

32 minutes ago, Miska said:

On digital cable front, I've been just trying to tell people NOT to use those damn shielded STP Ethernet cables in order to avoid totally screwing up the galvanic isolation Ethernet otherwise provides...

 

The reason not to use anything but cheap generic ethernet cable is very simple to explain

 

it is impossible for an ethernet cable or switch to change the audio. One of the advantages of using Ethernet is that the digitised audio is enclosed with  protocols which utilise crc ( cyclic redundancy check ). That means if you flip just one bit, the packet will be rejected for retransmission. This is how you manage to see a perfect page in your browser after the digitised data has traveled across countless ethernet cables and converters to get to you. The bits MUST arrive as sent. Take a look inside a Google or Microsoft server farm. Generic ethernet cables connecting everything.   No Ethernet cable can make a difference

 

I have forgotten Miska,  Are you in the 'USB cables can make a difference' camp or the ' thats impossible' camp ?

 

 

 

[DonaldT2109]

1 minute ago, DonaldT2109 said:

This is how you manage to see a perfect page in your browser after the digitised data has traveled across countless ethernet cables and converters to get to you

 

.....................and more relevant,   how Spotify plays a song perfectly on my system. There is nothing between the Spotify server and my DAC that can affect the music

[Miska]

42 minutes ago, DonaldT2109 said:

The reason not to use anything but cheap generic ethernet cable is very simple to explain

 

it is impossible for an ethernet cable or switch to change the audio. One of the advantages of using Ethernet is that the digitised audio is enclosed with  protocols which utilise crc ( cyclic redundancy check ). That means if you flip just one bit, the packet will be rejected for retransmission. This is how you manage to see a perfect page in your browser after the digitised data has traveled across countless ethernet cables and converters to get to you. The bits MUST arrive as sent. Take a look inside a Google or Microsoft server farm. Generic ethernet cables connecting everything.   No Ethernet cable can make a difference

 

You are again forgetting the important electrical path that works outside of the data transmission itself. Of course having been working on networking protocols and hardware design for ~30 years I have some kind of vague understanding how these things work.

 

Of course data transmission is error-free. But this is not the issue. It hugely matters if you use UTP or STP cable. Because STP cable connects grounds of two devices, potentially allowing dirty ground currents to flow, while UTP cable doesn't and the signals are galvanically isolated using transformers (if you don't use PoE). Transformer isolation exists there for a reason! STP cable can be only used if you have a very carefully designed grounding layout on your entire system (and not for long runs for various reasons).

 

44 minutes ago, DonaldT2109 said:

I have forgotten Miska,  Are you in the 'USB cables can make a difference' camp or the ' thats impossible' camp ?

 

I'm not in any black-and-white camp, I'm in the grey "devil is in the details" camp.

 

[Ralf11]

9 hours ago, Blackmorec said:

Oh boy....completely misinformed, as usual. 

 

https://uptoneaudio.com/pages/j-swenson-tech-corner

 

 

 

 

 

Indeed, you are completely mis-informed.  Your water pipe "analogy" is worthless for digital signals (tho valuable for teaching 3rd graders about electricity in general).

 

People posted several links to help educate you.  Read them.

 

John Swenson seems to be a nice guy but that link is not a white paper.

 

(not to say that he and uptone may be correct about noise from the USB gnd affecting some - some - DACs as Miska notes above)

 

 

 

[Cebolla]

1 hour ago, DonaldT2109 said:

 

.....................and more relevant,   how Spotify plays a song perfectly on my system. There is nothing between the Spotify server and my DAC that can affect the music

 

What a waste of a perfect delivery, given that Spotify's server doesn't send 'unaffected' music in the first place!

[Le Concombre Masqué]

1 hour ago, DonaldT2109 said:

 

The reason not to use anything but cheap generic ethernet cable is very simple to explain

 

it is impossible for an ethernet cable or switch to change the audio. One of the advantages of using Ethernet is that the digitised audio is enclosed with  protocols which utilise crc ( cyclic redundancy check ). That means if you flip just one bit, the packet will be rejected for retransmission. This is how you manage to see a perfect page in your browser after the digitised data has traveled across countless ethernet cables and converters to get to you. The bits MUST arrive as sent. Take a look inside a Google or Microsoft server farm. Generic ethernet cables connecting everything.   No Ethernet cable can make a difference

 

I have forgotten Miska,  Are you in the 'USB cables can make a difference' camp or the ' thats impossible' camp ?

 

 

 

man, do you ever read?

[DonaldT2109]

11 minutes ago, Le Concombre Masqué said:

man, do you ever read?

 

 

Read what exactly    ?

[DonaldT2109]

1 hour ago, Miska said:

It hugely matters if you use UTP or STP cable. Because STP cable connects grounds of two devices, potentially allowing dirty ground currents to flow, while UTP cable doesn't and the signals are galvanically isolated using transformers (if you don't use PoE). Transformer isolation exists there for a reason! STP cable can be only used if you have a very carefully designed grounding layout on your entire system (and not for long runs for various reasons).

 

Sorry Miska   

 

Can you not understand that the cables do not matter.   The protocols involved give perfect delivery

[crenca]

58 minutes ago, Miska said:

1 hour ago, DonaldT2109 said:

I have forgotten Miska,  Are you in the 'USB cables can make a difference' camp or the ' thats impossible' camp ?

 

I'm not in any black-and-white camp, I'm in the grey "devil is in the details" camp.

 

The thing is Miska, the usual Audiophile position/understanding/culture is that there are "details", described in the usual analogue/subjective language, that these high end cables deliver that effect your #1.  For example, this cable might "nail the midrange", while another cable might "expand the soundstage".  In otherwords, most of the time there is no informed/intelligent discussion or $sales$ going on around #2 (though it is referenced in the context of the $sales job$), rather #1.  

 

@DonaldT2109(who will win in 2020 guys, sorry to those who are not prepared 😋) point is this, the 99%, the Audiophile Cable Confidence Game...

[mansr]

6 minutes ago, DonaldT2109 said:

Sorry Miska   

 

Can you not understand that the cables do not matter.   The protocols involved give perfect delivery

Miska is correct in that STP Ethernet cables provide a path for noise to sneak in that UTP cables do not. Nothing to do with data delivery.

[DonaldT2109]

2 minutes ago, mansr said:

Miska is correct in that STP Ethernet cables provide a path for noise to sneak in that UTP cables do not. Nothing to do with data delivery.

 

Forget the cables and read up on communications protocols, particularly those dealing with audio (or anything else for that matter)

In your scenario Internation telephone conversations would grind to a halt, All IP telephony would stop ,you wouldn't be able to talk on Skype or Whatsapp.  The protocols used allow all of these systems to use audio ( and video) with no problems

[DonaldT2109]

Back to the matter in hand....       USB Audio

 

I am willing to learn, maybe I am wrong. So I would like you to explain soething to me

 

Let's say that I want to play my 16-bit/44.1kHz FLAC of 'Take 5'  (superb BTW)
I play to USB on my Linux system bypassing any EQ or otherwise. Bits from file sent to USB 'as is'

 

If I use, for example, the Audioquest Diamond, will I acheive bit for bit transport of the digital stream being sent by my USB port to my DAC.   
i.e     will the DAC see the same digital stream that was presented to my USB port

 

(I am guessing yes, otherwise the cable would be totally useless because with my current 'cheap' cable the answer is yes)

 

but please confirm YES or NO         (just yes or no for now please, no drifting into clocks and jitter and other stuff    )

[John Dyson]

6 minutes ago, mansr said:

Miska is correct in that STP Ethernet cables provide a path for noise to sneak in that UTP cables do not. Nothing to do with data delivery.

And bringing it back to the 'soundstage' matter -- none of these things affect 'soundstage', but instead perhaps at most a very small amount of noise often due to poor circuit layout that allows bad cables to have negative effects.   My earlier comments were about the 'soundstage matter', then effectively morphed into poorly designed electronics and layout...   On poorly designed circuitry (physically and/or electronically), cable effects (and even human body movement) can have negative effects on the analog audio signal.   When discussions get down to that level, it only becomes a mass of obfuscations.

 

Can we all agree that inadequate designs (either specification or implementation) can cause almost any problem in a system -- including noise?   A really bad design can have intermittent shorts, thereby creating VERY BAD 'soundstage' issues - like nonexistent signals, dropouts and loud splats, but again -- this kind of discussion becomes nonsensical unless there is common purpose in solving an actual problem :-).

 

When it comes to USB (or most other digital transport) cables, in a discussion that isn't degenerated to the absurd, 'sounstage', 'image' just isn't an issue.  Hardware problems can cause infinite kinds of problems, limited only by the lack-of-imagination by the original designer of defective equipment and cables.

We aren't generally (including me), hobbyists who are  currently designing and building audio interface and digital transport hardware.   A few of us might be doing it professionally, but we should always condition those discussions by making sure that we are talking about 'prototype' hardware and designs!!!   There are a myriad of problems encountered in the design and testing of devices that simply should not be encountered (very often) by j.random audiophile.

 

John