Digital Signal Transmission

[TomJ]

@PeterSt

Sorry if I was a little too rude. I have just come back from endless discussion in another forum regarding digital audio and it always ended with the same esoteric statements and "I can hear the difference" without any explanation. I have great respect for your work!

With "passiv" I used the wrong word for the Intona. I know, that it use the USB  power.

Daniel Stämmler has not yet developed a passive isolator.

 

And TCP/IP was not mentioned as a solution for the USB topic. I come from IT and I'm a bit tired of the discussions about jitter effects on sound in network transmission. There is a solution for this and that is the TCP / IP protocol, which compensates for possible errors on lower ISO layers. But if I'm wrong here, I ask for clarification.

 

@Superdad

Same to you - neither I “just fell off the turnip truck” or I am trolling.

With regard to the popularity of Amir, there seems to be a need for transparency and comparability. There are apparently a lot of people who are fed up with just esoteric talk without explanations. If you have better measuring devices and methodologies, then I think measurements with this would be welcome. It is too easy to just discredit Amir.

 

[Superdad]

38 minutes ago, TomJ said:

I come from IT and I'm a bit tired of the discussions about jitter effects on sound in network transmission. There is a solution for this and that is the TCP / IP protocol, which compensates for possible errors on lower ISO layers. But if I'm wrong here, I ask for clarification.

 

Okay, let's see how few words I can condense this into:

 

Like everything else in this digital world, Ethernet is voltages into chips that run from clocks.  And not even binary at that: 100Mbps is 3 voltage levels, Gigabit is 5 voltage levels.  Just like everything else, the clocks are voltages with a rise time.  And clock voltages are referenced to some 0-volt "ground" plane.  Allow ground plane noise to enter an endpoint device (one that ultimately has a path to an audio rate master clock pin) and you end up with a bouncing "ground." Since the clock is not a perfect zero-rise-time square wave, movement of the 0-volt reference is laterally moving (in time) the clock voltage threshold of whatever chip is running off it. Jitter.

 

Plus every chip--be it a PHY, MAC processor, FPGA, digital isolator, or flip-flop--generates its own noise (often via high-speed current draw spikes) and jitter.

 

Separately, the causes of the above--ground-plane-noise/clock-threshold jitter--range from common-mode noise and leakage currents to upstream phase-noise (jitter) induced perturbations. And all that stuff adds up and becomes audible.

 

Not going to go down the rabbit hole with anyone about why this above eludes standard FFT measurements at the analog output. That's a separate debate for which I will not take the bait.  

 

Funny thing is: DAC and other digital engineers (especially if you get into RF, telecommunications, and microwave engineering) deal with the ground-plane and clock issues in their designs as a matter-of-course. Really nothing new of controversial about any of it.  What the armchair engineers, network guys--and even those designers who think nothing gets into their box--are missing is that immunity from electrical factors does not automatically come with every packet data interface, be it USB or Ethernet.

 

[ray-dude]

4 minutes ago, Superdad said:

Funny thing is: DAC and other digital engineers (especially if you get into RF, telecommunications, and microwave engineering) deal with the ground-plane and clock issues in their designs as a matter-of-course. Really nothing new of controversial about any of it.

 

+1000 this.  The amount of hard core engineering that goes into these factors is off the charts.  I too find it amazing that folks extrapolate idealized abstractions to how things actually work at the physical layer.  Abstractions are critical for operating at a higher level (network stacks, switches, kernels, etc), but we have to focus on the reality at the level of reality we're trying to manage/optimize.  

 

If you care about the ground and reference voltage plane and how noise (and self induced noise) on these planes impacts a D to A circuit, you have to operate at that level, not the bits are bits level.  If you're building a streaming service, you operate at the socket and protocol level, not the bits are bits level.  

 

Different horses for different courses, and a large part of the art of engineering is the wisdom to know which idealized abstractions to apply and optimize for different design challenges.

[TomJ]

19 minutes ago, Superdad said:

 

Okay, let's see how few words I can condense this into:

 

Like everything else in this digital world, Ethernet is voltages into chips that run from clocks.  And not even binary at that: 100Mbps is 3 voltage levels, Gigabit is 5 voltage levels.  Just like everything else, the clocks are voltages with a rise time.  And clock voltages are referenced to some 0-volt "ground" plane.  Allow ground plane noise to enter an endpoint device (one that ultimately has a path to an audio rate master clock pin) and you end up with a bouncing "ground." Since the clock is not a perfect zero-rise-time square wave, movement of the 0-volt reference is laterally moving (in time) the clock voltage threshold of whatever chip is running off it. Jitter.

 

Plus every chip--be it a PHY, MAC processor, FPGA, digital isolator, or flip-flop--generates its own noise (often via high-speed current draw spikes) and jitter.

 

Separately, the causes of the above--ground-plane-noise/clock-threshold jitter--range from common-mode noise and leakage currents to upstream phase-noise (jitter) induced perturbations. And all that stuff adds up and becomes audible.

 

Not going to go down the rabbit hole with anyone about why this above eludes standard FFT measurements at the analog output. That's a separate debate for which I will not take the bait.  

 

Funny thing is: DAC and other digital engineers (especially if you get into RF, telecommunications, and microwave engineering) deal with the ground-plane and clock issues in their designs as a matter-of-course. Really nothing new of controversial about any of it.  What the armchair engineers, network guys--and even those designers who think nothing gets into their box--are missing is that immunity from electrical factors does not automatically come with every packet data interface, be it USB or Ethernet.

 

So we're talking about jitter that happens in the DAC when converting from D to A due to noise from the ethernet line? Not about jitter that leads to wrong data? I would be suspicious of this, but it is understood that way by many and therefore I am giving the TCP / IP argument.

 

[Superdad]

3 minutes ago, TomJ said:

Not about jitter that leads to wrong data?

Bingo!  What goes on--and what our own highly unique EtherREGEN is all about--has zero to do with changing the bits. Never has.  A $20 switch will transmit the same data. It is the secondary electrical factors at play--which are affecting various stages downstream.

[sandyk]

4 hours ago, pkane2001 said:

That's what objective evidence is, Alex.

 

 Bovine excreta  !

Just as your usual assumption that it is below the audibility threshold is  if it's over -120dB

 Your typical stance appears to be  " IF I can't measure it, then you can't hear it" 

 Yet you were unable to measure the things that Frank confirmed hearing, as another poster  from the Objective side also did, then attempted to distance himself from it. In that case it was with a couple of comparisons that sounded different despite identical Binary content, where I then removed a few mS from the beginning of one track so that they no longer had identical SHA256 checksums, yet still sounded different to both posters.

 You should find those posts somewhere in the Objective area unless the OP later edited them out to to suit his desired conclusions .

[TomJ]

12 minutes ago, Superdad said:

Bingo!  What goes on--and what our own highly unique EtherREGEN is all about--has zero to do with changing the bits. Never has.  A $20 switch will transmit the same data. It is the secondary electrical factors at play--which are affecting various stages downstream.

The problem I have, that many people i discuss with how a network device can improve the sound dont understand that even with streaming services over the internet, there is no missing bit when the stream arrives in their streamer. They argue with UDP protocols and missing bits and this should be the reason why better "audiophile" switches improve the sound. And i am sick about these discussions.

 

If I am using a network isolator, then the noise will be lowered -right?

 

I use such an isolator in front of my streamer and an isolator between streamer and dac.

Isn't this enough to keep the noise outside of the dac?

 

 

[pkane2001]

5 minutes ago, sandyk said:

 Bovine excreta  !

Just as your usual assumption that it is below the audibility threshold is  if it's over -120dB

 Your typical stance appears to be  " IF I can't measure it, then you can't hear it" 

 Yet you were unable to measure the things that Frank confirmed hearing, as another poster  from the Objective side also did, then attempted to distance himself from it. In that case it was with a couple of comparisons that sounded different despite identical Binary content, where I then removed a few mS from the beginning of one track so that they no longer had identical SHA256 checksums, yet still sounded different to both posters.

 You should find those posts somewhere in the Objective area unless the OP later edited them out to to suit his desired conclusions .

Alex, civilized behavior would be much appreciated.
 

And what’s your obsession with checksums? As far as I can tell they have nothing to do with this conversation, and yet you keep bringing them in.

[sandyk]

2 minutes ago, TomJ said:

. They argue with UDP protocols and missing bits and this should be the reason why better "audiophile" switches improve the sound. And i am sick about these discussions.

 The obvious answer then is to ignore this forum and listen to, and view the world according to Amir and his purely measurement brigade in  A.S. where you presumably are already a devoted member ?.

[TomJ]

Just now, sandyk said:

 The obvious answer then is to ignore this forum and listen to, and view the world according to Amir and his purely measurement brigade in  A.S. where you presumably are already a devoted member ?.

So if there is no consensus in this forum that the data will be sent correctly over the network to the network end device and that this is the basis for discussion here in this forum, then you are right.
I'm not talking about the fact that a switch cannot increase the sound quality, but that it does not change the data less than 20 $ switches.

[sandyk]

3 minutes ago, pkane2001 said:

Alex, civilized behavior would be much appreciated.

 Then stop bringing my name back into it, and ridiculing my reports about improving the earthing of many typical PCs as discussed by one and a half in his thread.

 

[pkane2001]

4 minutes ago, sandyk said:

 Then stop bringing my name back into it, and ridiculing my reports about improving the earthing of many typical PCs as discussed by one and a half in his thread.

 

Hate to tell you, but you weren’t the Alex I was addressing.

[sandyk]

1 minute ago, TomJ said:

I'm not talking about the fact that a switch cannot increase the sound quality, but that it does not change the data less than 20 $ switches.

Nobody is disputing that a switch can not increase the sound quality. 

What you refuse to accept is that the quality of the switch and it's power supply can DEGRADE the sound quality based solely on the assumption that the Data remains unchanged ,even though there may also be RF/EMI going along for the ride too, which MAY affect the resulting sound quality.

[One and a half]

1 minute ago, TomJ said:

So if there is no consensus in this forum that the data will be sent correctly over the network to the network end device and that this is the basis for discussion here in this forum, then you are right.
I'm not talking about the fact that a switch cannot increase the sound quality, but that it does not change the data less than 20 $ switches.

Since you are not electrically minded, think of the noise that is on top of the USB signal as a virus. Currently the tools we have to measure that virus is a 18th century telescope. We know it’s there, can hear the effects, make a good guess of what it is, but cannot measure.

Thats why there is very little data since it is difficult to measure in the first place. When I mean difficult the instruments are well beyond most professionals starting at EUR150k +++ and that won’t get anywhere close.

[pkane2001]

Just now, One and a half said:

Since you are not electrically minded, think of the noise that is on top of the USB signal as a virus. Currently the tools we have to measure that virus is a 18th century telescope. We know it’s there, can hear the effects, make a good guess of what it is, but cannot measure.

Thats why there is very little data since it is difficult to measure in the first place. When I mean difficult the instruments are well beyond most professionals starting at EUR150k +++ and that won’t get anywhere close.

What’s so difficult about measuring noise in an analog signal? It’s really not rocket science. I’ve not heard of such expensive equipment being required for the task. What exactly does this super-instrument measure?

[Superdad]

20 minutes ago, TomJ said:

The problem I have, that many people i discuss with how a network device can improve the sound dont understand that even with streaming services over the internet, there is no missing bit when the stream arrives in their streamer. They argue with UDP protocols and missing bits and this should be the reason why better "audiophile" switches improve the sound. And i am sick about these discussions.

Then you are discussing with the wrong people on the wrong forums.  Because neither I nor anybody reasonable I have seen in the 13 years I've been here have ever said that the bits--be they via USB or Ethernet--are changing.

 

20 minutes ago, TomJ said:

If I am using a network isolator, then the noise will be lowered -right?

Mighty much too generic terms there--"network isolator" and "noise."  

Like going to the doctor and saying: "If I am taking medicines then sicknesses will be better, right?"

Or to the chef and stating "My food will be better with spices."

[sandyk]

15 minutes ago, pkane2001 said:

Hate to tell you, but you weren’t the Alex I was addressing.

 Your reply is every bit addressed to all participants in this thread, and once again is being used to ram down our throats content from ASR that most members are not interested in, or if they are, can choose to view their content directly.

 

Did you first seek permission from ASR Admin to repost their content in this forum ? 

 

 

[fas42]

Just to throw into the debate about "what matters" - the low cost digital speakers I currently use, which has all the digital stuff coming in via the lowest cost optical link - now has achieved immunity, something I have never achieved before, from mains noise; to as far as I've been able to detect, subjectively. Now, I have had to put in lots and lots of time exploring this - and has required "extreme" isolating techniques.

 

This, Yet Again, emphasises how sensitive digital playback is to any noise which "shouldn't be there!" - meaning, any link which involves galvanic connection to another device which is a possible source of noise, should always be suspected - just putting up graphs which show magical competence in some parameter, which may or may not be relevant to what you hear, is not going to get you closer to a "final solution".

[kumakuma]

[pkane2001]

3 minutes ago, sandyk said:

 Your reply is every bit addressed to all participants in this thread, and once again is being used to ram down our throats content from ASR that most members are not interested in, or if they are, can choose to view their content directly.

 

Did you first seek permission from ASR Admin to repost their content in this forum ? 

What’s your problem, Alex? You don’t agree with what I say, I know that. But being rude and trying to insult me is just childish behavior.

[sandyk]

1 minute ago, kumakuma said:

 Yet the OP has not posted any OBJECTIVE proof of his statements whatsoever .

[One and a half]

2 minutes ago, pkane2001 said:

What’s so difficult about measuring noise in an analog signal? It’s really not rocket science. I’ve not heard of such expensive equipment being required for the task. What exactly does this super-instrument measure?

Ok, any high impedance probe on a scope has far too low an impedance to measure this conducted noise. It is necessary to have several gigs of impedance, so the scope will have no influence. 18th century telescope is what we have now.

It easier to measure noise at frequencies above 30 MHz, since the receiver is decoupled from the source. Soon as there are conducted emissions through a wire, the story radically changes.

[TomJ]

14 minutes ago, Superdad said:

Like going to the doctor and saying: "If I am taking medicines then sicknesses will be better, right?"

Or to the chef and stating "My food will be better with spices."

But the problem then seems to be more about making the diagnosis. But how, without measurements? Seems to be a gamble.

[pkane2001]

9 minutes ago, One and a half said:

Ok, any high impedance probe on a scope has far too low an impedance to measure this conducted noise. It is necessary to have several gigs of impedance, so the scope will have no influence. 18th century telescope is what we have now.

It easier to measure noise at frequencies above 30 MHz, since the receiver is decoupled from the source. Soon as there are conducted emissions through a wire, the story radically changes.

Then it should be trivial to show  an example that demonstrates the need for such high impedance probes. Something that demonstrates that with standard probes or the cheaper analyzer probes there’s some significant noise that’s being missed. Can you please share this? 

[fas42]

26 minutes ago, TomJ said:

But the problem then seems to be more about making the diagnosis. But how, without measurements? Seems to be a gamble.

 

Ah, good ol' measurements - if you are suffering pain, and I can't measure anything, then it must be in your head - the scientific community can't exist if this fundamental truth is not accepted, 🤪.

 

The pain of poor sounding playback will just go away if you keep studying graphs and charts of brilliant measurements, taken of your gear on the testbench ... take twice daily, or as needed. 🙂