Digital Signal Transmission

[PeterSt]

4 hours ago, pkane2001 said:

Of course! Got anything objective to back up this bold and exciting claim? I'm ready to weld if you do 🤪

 

Paul, you are so funny. But I am sure that you think that the "quality" of a PC does not matter. Am I right ?

I mean, if this is clear(ed) then we can understand your fun better.

 

PS: I am half-serious. But you'll know what I mean. So your answer is of some importance (which is also half-serious, but 0.5 + 0,5 makes 1).

[sandyk]

8 minutes ago, PeterSt said:

 

Alex, I think you may be confusing the handshake procedure with ground being required. Maybe in some occasions +5V is needed (I don't know about them - but that doesn't tell much 🤪) but ground most often (always ?) is required. And this ground is not required for the data ...

 No Peter .

Some DACs do need to see+5V, but all seem  to need the 0 volts reference 

[PeterSt]

7 hours ago, TomJ said:

and you show me the dirt of USB power and all the people think USB is eval.

 

Tom, USB *is* evil. Trust me. It can be turned into an interface with lower jitter than SPDIF, but this is so difficult that it took 6 or 7 years after asynchronous USB was "invented" for audio to get there by one or two DAC manufacturers.

 

And a hint for you (it could silence you somewhat 🤫): USB implies a relatively very high 8KHz signal, which is right in the audio band. It is pure distortion. Here too, it is the most hard to tame, but it can be done to at least something which should be inaudible, but which will still always be measurable.

In itself this signal implies (data-) jitter, because it is an oscillation beating with the DAC's audio clock.

[PeterSt]

6 minutes ago, sandyk said:

No Peter .

Some DACs do need to see+5V, but all seem  to need the 0 volts reference 

 

Ahem. I was saying that ?

[sandyk]

1 minute ago, PeterSt said:

 

Ahem. I was saying that ?

You said MAYBE in some cases. I wasn't disagreeing with you

[PeterSt]

OK, I am apparently missing your point. Never mind.

 

Maybe to clarify - the 0 volt reference is required for the handshake procedure (which is at connecting the DAC, or powering it up - or powering up the PC). After that has been established, the ground can be removed. Not that I tried this with all DACs. 😝

 

Thinking about this, I am pretty sure that these days I would be able to provide that ground locally (thus not over USB). It would be illegal ground all right, but it would be harmless just the same because it will only be used at this handshake.

Oh wait, this is Covid-19. No handshakes !

[pkane2001]

38 minutes ago, PeterSt said:

 

Paul, you are so funny. But I am sure that you think that the "quality" of a PC does not matter. Am I right ?

I mean, if this is clear(ed) then we can understand your fun better.

 

PS: I am half-serious. But you'll know what I mean. So your answer is of some importance (which is also half-serious, but 0.5 + 0,5 makes 1).

The quality of the case rivets doesn’t matter if it’s properly grounded, Peter.

[sandyk]

17 minutes ago, pkane2001 said:

The quality of the case rivets doesn’t matter if it’s properly grounded, Peter.

You are also ignoring the fact that the metal cases of SSD/HDD are internally connected to 0 volts. This means that if the case has a very low resistance back to the 0 volts (Earth) of the PSU via the metalwork that there will be a marked reduction in the measured rubbish voltage between the SSD/HDD case and 0 volts of the PSU with an SSD that is not securely earthed via the metalwork.  I also found a voltage drop between the top and bottom halves of my drive bay that were joined together using pop rivets. Some people apparently even go to the trouble of replacing the rivets with silver rivets !

 Remember too, that the power to some SSDs etc. may go via a couple of daisy chained 4 pin Molex connectors using cheap metal contacts that aren't always 100% reliable, and that SSDs may even generate enough RF/EMI to affect WiFi if not properly earthed and screened.

 

 

 

 

14A2-B4.pdf

[TomJ]

3 hours ago, PeterSt said:

 

Tom, USB *is* evil. Trust me. It can be turned into an interface with lower jitter than SPDIF, but this is so difficult that it took 6 or 7 years after asynchronous USB was "invented" for audio to get there by one or two DAC manufacturers.

 

And a hint for you (it could silence you somewhat 🤫): USB implies a relatively very high 8KHz signal, which is right in the audio band. It is pure distortion. Here too, it is the most hard to tame, but it can be done to at least something which should be inaudible, but which will still always be measurable.

In itself this signal implies (data-) jitter, because it is an oscillation beating with the DAC's audio clock.

Hi Peter,

I always find it funny how you are immediately dismissed as ignorant in these audiophile forums when you ask questions that do not fit into the worldview.
I am not an electrical engineer and I will not become one.
I have spoken of it myself that I am amazed at the amount of effort that is sometimes put into it and I do not understand it because it does not reveal itself to me with my knowledge.
I keep getting answers that bad jitter is to blame and that jitter is also the cause of the deterioration of the sound over the network - which is absolute nonsense, since all systems use TCP / IP.
For your information: I have a streamer that is operated with an LPS (I am aware that the USB power is otherwise useless). The streamer streams via USB to an Intona isolator, which is passive and has no other power supply, such as the Uptone Regen and therefore does not worsen the power situation.
Between the isolator and the RME ADI 2 DAC is a NEO Oyaide d + Class S cable, on which the + 5V contacts are masked on both sides.

Which DACs are you talking about that have overcome the USB problem? 

[pkane2001]

10 hours ago, PeterSt said:

 

Tom, USB *is* evil. Trust me. It can be turned into an interface with lower jitter than SPDIF, but this is so difficult that it took 6 or 7 years after asynchronous USB was "invented" for audio to get there by one or two DAC manufacturers.

 

And a hint for you (it could silence you somewhat 🤫): USB implies a relatively very high 8KHz signal, which is right in the audio band. It is pure distortion. Here too, it is the most hard to tame, but it can be done to at least something which should be inaudible, but which will still always be measurable.

In itself this signal implies (data-) jitter, because it is an oscillation beating with the DAC's audio clock.

 

Peter,  I think you're making very general statements that are a bit out of date and not supported by facts. The 8KHz signal caused by Isochronous protocol's microframes has been mostly defeated or down to a very low level, usually below -120dBFS. Even in many inexpensive DACs over the past few years. Any "beating" or interaction with the DAC clock would be at a level below that. Here's an example. Do you see anything of concern here at 8KHz or anywhere else? This is a tiny portable DAC powered by USB, under $200:

 

 

Another $200 DAC, see any 8KHz here?

 

On the other hand, here's a Schiit Modi 3+ with a custom USB input (Unison) - a $99 DAC. A tiny blip of 8KHz signal visible, at about -140dBFS:

 

Now compare this to the same Schiit Modi 3+ DAC over SPDIF, tell me which one is better:

[pkane2001]

6 hours ago, TomJ said:

Hi Peter,

I always find it funny how you are immediately dismissed as ignorant in these audiophile forums when you ask questions that do not fit into the worldview.
I am not an electrical engineer and I will not become one.
I have spoken of it myself that I am amazed at the amount of effort that is sometimes put into it and I do not understand it because it does not reveal itself to me with my knowledge.
I keep getting answers that bad jitter is to blame and that jitter is also the cause of the deterioration of the sound over the network - which is absolute nonsense, since all systems use TCP / IP.
For your information: I have a streamer that is operated with an LPS (I am aware that the USB power is otherwise useless). The streamer streams via USB to an Intona isolator, which is passive and has no other power supply, such as the Uptone Regen and therefore does not worsen the power situation.
Between the isolator and the RME ADI 2 DAC is a NEO Oyaide d + Class S cable, on which the + 5V contacts are masked on both sides.

Which DACs are you talking about that have overcome the USB problem? 

 

RME ADI 2 DAC is pretty much immune to the usual noise from USB line, so ignore any potential issues with PC case rivets or 8KHz noise :)

 

[TomJ]

1 hour ago, pkane2001 said:

 

RME ADI 2 DAC is pretty much immune to the usual noise from USB line, so ignore any potential issues with PC case rivets or 8KHz noise :)

 

I have the V1 RME ADI 2 DAC, which looks also quiet perfect with "eval" USB:

 

 

@PeterSt:

Here is a comparison of S/PDIF vs. USB - USB is the clear winner:

https://www.audio “science” review/forum/index.php?threads/battle-of-s-pdif-vs-usb-which-is-better.1943/

 

But now I must read next, that this measurement is garbage because not done with the super duper master clock and done with garbage DACs and not with 10T$ DACs and you must use your ears, bla bla bla. This is what I meant with the myths around digital audio. The measurements shows, that USB is better, but If you post this in forums you are directly portrayed as a fool without a clue. 

 

Here are the Measurements S/PDIF vs USB:

 

 

 

 

[TomJ]

An other thought I want to share:

Maybe USB is not so popular because you can't fumble around here enough and you can't make such a big secret about the great sound optimizations. Actually a big annoyance for all "magicians" of the great sound. 

[pkane2001]

16 minutes ago, TomJ said:

Maybe USB is not so popular because you can't fumble around here enough and you can't make such a big secret about the great sound optimizations.

 

 Where there's a will, there's always a way 😄   

 

[Superdad]

34 minutes ago, TomJ said:

Here is a comparison of S/PDIF vs. USB - USB is the clear winner:

Show me where @PeterSt was arguing in favor of S/PDIF over USB.  Peter has been designing serious DACs for at least a couple of decades—and has been pushing the envelope on USB input for his DAC. And he has some very sensitive measurement gear.

In fact, his DAC is one of only two on the market (the other being the Auralic Vega G2) with USB galvanic isolation at the input—BEFORE the USB PHY/MAC processor.

 

I think it is funny how some folks buy into the notion that the ex-Microsoft guy who bought an AP analyzer and floods the net with graphs somehow is somehow smarter than all the high-end engineers and chip guys who have been deep in this for decades. I could compile a list of renowned engineers (including Mike Moffat, Damian Martin, Ted Smith, John Curl, Michael Pflaumer, and Keith Johnson) who Amir has basically dubbed “hacks.”

[Superdad]

21 minutes ago, TomJ said:

Maybe USB is not so popular...

Huh? Did you know that this site was formerly called “Computer Audiophile.”

Now we know that you either “just fell off the turnip truck” or are simply trolling...

[PeterSt]

2 hours ago, pkane2001 said:

Peter,  I think you're making very general statements that are a bit out of date and not supported by facts.

 

Maybe it is too difficult to understand my poor English. I never said that today this is still a problem. I only said it has been hard to overcome. And sure, once one gets it done, all can do it, as long as the data is shared.

 

Your measurements show nothing as the noise level is too high (hence the FFT not deep enough etc.). Next up is your (obviously) expected "but you can't hear that". I think I was ahead of you with that one.

 

Tell me again where I was wrong of off somewhat.

N.b.: You could ask me to show the 8KHz at just over -160dB - but it is useless because that too would be from I think 2015, and techniques  undoubtedly improved again.

 

Quote

Any "beating" or interaction with the DAC clock would be at a level below that.

 

Ah, OK. So it won't imply jitter.

No wait, that jitter would be at inaudible levels.

[pkane2001]

12 minutes ago, PeterSt said:

 

Maybe it is too difficult to understand my poor English. I never said that today this is still a problem. I only said it has been hard to overcome. And sure, once one gets it done, all can do it, as long as the data is shared.

 

Your measurements show nothing as the noise level is too high (hence the FFT not deep enough etc.). Next up is your (obviously) expected "but you can't hear that". I think I was ahead of you with that one.

 

Tell me again where I was wrong of off somewhat.

N.b.: You could ask me to show the 8KHz at just over -160dB - but it is useless because that too would be from I think 2015, and techniques  undoubtedly improved again.

 

 

Ah, OK. So it won't imply jitter.

No wait, that jitter would be at inaudible levels.

 

Wait... -160dBFS isn't deep enough for you? What is?

[PeterSt]

8 hours ago, TomJ said:

I keep getting answers that bad jitter is to blame and that jitter is also the cause of the deterioration of the sound over the network - which is absolute nonsense, since all systems use TCP / IP.

 

Somehow TCP/IP seems to be a solution for you, while it solves completely nothing.

 

8 hours ago, TomJ said:

For your information: I have a streamer that is operated with an LPS (I am aware that the USB power is otherwise useless). The streamer streams via USB to an Intona isolator, which is passive and has no other power supply

 

For your information, ever back half the world was using the Intona USB isolator because I brought it to the audio market. Maybe you like to see my serial number 00001 ?

I now use it as a cable lifter.

For your information, the Intona is not so much passive with its two FPGAs inside. Unless the German innovator now has a passive solution indeed. In that it case it sure was for "my information".

 

Quote

Which DACs are you talking about that have overcome the USB problem?

 

Maybe it depends on what USB problem you refer to, but let's say "all" which cost a little more. Please keep in mind that I only referred to the difficulty of getting there.

If you meant the "one or two" I mentioned who solved it at first, well ... I'd like to mention exaSound as the second. The first I already mentioned somewhere (haha).

 

1 hour ago, TomJ said:

Here is a comparison of S/PDIF vs. USB - USB is the clear winner:

 

Of course. And I did not say it wouldn't. Still FYI, if I would make a new design all over, I would attempt S/PDIF.

Btw, you can't come up with general FFTs of general S/PDIF DACs. I'd try Chord (768KHz S/PDIF). I never looked myself (or tried to find FFT plots from it) but I think I can guess it ...

[PeterSt]

7 minutes ago, pkane2001 said:

Wait... -160dBFS isn't deep enough for you? What is?

 

Always in good spirit Paul. So now I said that -160dB isn't good enough ?

Where ?

I only said that it is still measurable. IIRC that is.

[PeterSt]

1 hour ago, TomJ said:

Here is a comparison of S/PDIF vs. USB - USB is the clear winner:

 

Ahem. I only see now that you used exaSound yourself as the example. Apologies if I stipulated something obvious. But they really were the first to show as low noise figures etc. as I could create it myself.

 

[pkane2001]

26 minutes ago, Superdad said:

Show me where @PeterSt was arguing in favor of S/PDIF over USB.  Peter has been designing serious DACs for at least a couple of decades—and has been pushing the envelope on USB input for his DAC. And he has some very sensitive measurement gear.

In fact, his DAC is one of only two on the market (the other being the Auralic Vega G2) with USB galvanic isolation at the input—BEFORE the USB PHY/MAC processor.

 

I think it is funny how some folks buy into the notion that the ex-Microsoft guy who bought an AP analyzer and floods the net with graphs somehow is somehow smarter than all the high-end engineers and chip guys who have been deep in this for decades. I could compile a list of renowned engineers (including Mike Moffat, Damian Martin, Ted Smith, John Curl, Michael Pflaumer, and Keith Johnson) who Amir has basically dubbed “hacks.”

 

I don't think Amir is smarter than anyone. But, his measurements are there for everyone to examine, interpret, and try to disprove or confirm, unlike some of the manufacturers that promise these for years after making claims and releasing a product ;) That's what objective evidence is, Alex.

 

[pkane2001]

5 minutes ago, PeterSt said:

Always in good spirit Paul. So now I said that -160dB isn't good enough ?

Where ?

 

Here you go:

Quote

Your measurements show nothing as the noise level is too high (hence the FFT not deep enough etc.). 

 

Since the measurements I posted go down to -160dBFS, and you say the noise level is too high, I assume you are looking for something lower? By the way, that's just the FFT noise floor, I can go deeper with larger FFT, but why would I want to?

[PeterSt]

31 minutes ago, Superdad said:

I think it is funny how some folks buy into the notion that the ex-Microsoft guy who bought an AP analyzer and floods the net with graphs somehow is somehow smarter than all the high-end engineers and chip guys who have been deep in this for decades.

 

Ha ! The phrase of the day !! No, the month.

 

Quote

I could compile a list of renowned engineers (including Mike Moffat, Damian Martin, Ted Smith, John Curl, Michael Pflaumer, and Keith Johnson) who Amir has basically dubbed “hacks.”

 

I surely would incorporate John Swenson (you would too !) and if you'd allow me: you too. Bringing technologies together is as important (count in Jesus R regarding this. Barrows. There are more.)

 

Damian would typically come up with rivets. Just saying. Haha.

[PeterSt]

Quote

Since the measurements I posted go down to -160dBFS

 

 

@pkane2001, Paul, you sure did show that. I overlooked this one :