Is Digital Audio A Mature Science?

[One and a half]

Just now, sandyk said:

 

Agreed, but the amplifier would also extend the workable distance, as well as retaining  an excellent waveform requiring less processing in the Input receiver.

S/PDIF needs levels looked at carefully. 0.5V pp is it, no more, video is 1vpp (nominal), the gain has to be watched with some diligence. That's the major reservation I have with the device.

[sandyk]

Quote

S/PDIF needs levels looked at carefully. 0.5V pp is it, no more, video is 1vpp (nominal), the gain has to be watched with some diligence. That's the major reservation I have with the device.

 

As the I.C.s have a fixed gain of 2 , using 75 ohm output and input resistors  you would only need to set the input level to 0.5V pp.

 I just wish that I had another Max497 PCB to try this out. The small MAX497 PCB even has the associated 7805 and 7905 mounted on it.

[KeenObserver]

So, how many angels can dance on the head of a pin?

 

Let me see if I can understand this.  Even though trillions of bits of data are ACCURATELY sent around the world every day,  we cannot send music bits accurately?

 

In order to enjoy music we need to play vinyl on a turntable on a "high order" system?

[KeenObserver]

Those music bits are rascally little devils.  Got a mind of their own.

[sandyk]

3 minutes ago, KeenObserver said:

Those music bits are rascally little devils.  Got a mind of their own.

 

 Both Digital Audio and Digital Video are affected by Jitter, timing issues, the quality of the power supplies, and System noise going along for the ride when they become an ANALOGUE replica of the original binary signal when exported to the DAC/receiver for reconstruction.

 

 The link to the thread attached which is possibly the largest thread in the history of C.A. (494 pages) will also show that numerous other C.A. members do not agree with you either.

https://www.computeraudiophile.com/forums/topic/30376-a-novel-way-to-massively-improve-the-sq-of-computer-audio-streaming/

 

However you of course know better, so I have no interest in  discussing this further and will not be doing so in this thread..

[KeenObserver]

"However you of course know better, so I have no interest in  discussing this further and will not be doing so in this thread."

 

Thank You.

[KeenObserver]

That was me being civil.

[fas42]

People are significantly overthinking, and overcomplicating things: all that is necessary in every variation of a rig, is for the music data to be presented to the remainder analogue circuitry so that that the latter circuitry is not impacted in any way by how the digital waveforms were generated and transferred. Unfortunately, this is harder than many people realise, hence all the carry on. Whether a CD player, USB delivery, online streaming, whatever - the analogue areas are often interfered with; very subtle at times - but enough to do the damage.

 

If one wants to systematic about this, one could create an extremely simple system, where the music data of a single track is hard coded in just enough circuitry to enable it to be fed to the DAC - zero fanciness, anywhere. What does it sound like? Then, bit by bit, add in all the extra goodies that real world rigs normally rely upon, in the myriad variations - does the quality degrade at certain points; using certain retrieval methods. If some mechanism for sourcing the music data is shown to damage the SQ, then the answer is to improve the engineering, so that the electrical isolation is adequate.

[fas42]

While people want to cling to the glorious belief that there are zero pathways for analogue areas of the playback chain to be affected by electrical behaviours on the "digital" side, the arguments will continue ...

[KeenObserver]

ALL components in the chain are subject to the possibility of creating extraneous noise!  Every components has a power supply.  Every component creates heat.

As I said in another thread,  any first year EE student is probably capable of isolating noise.

[Ralf11]

but they may not have done so...

 

He presented a good check list:

1. Jitter, timing issues,

2. quality of the power supplies

3. not sure what was meant by "system noise"

and there may also be 4. noise from various processes in the computer

 

I won't claim they are always an issue, but won't claim they are never an issue either.  One needs to measure.

[fas42]

Quote

As I said in another thread,  any first year EE student is probably capable of isolating noise

 

To a certain degree, yes. The hard thing to nail is the level to which one has to go, to "guarantee it's inaudible".

 

IME, the better the system gets, the easier it is to detect the impact of extraneous noise - it's like stopping that  clock from starting to bug you ...

 

 

[One and a half]

5 hours ago, sandyk said:

 

As the I.C.s have a fixed gain of 2 , using 75 ohm output and input resistors  you would only need to set the input level to 0.5V pp.

 I just wish that I had another Max497 PCB to try this out. The small MAX497 PCB even has the associated 7805 and 7905 mounted on it.

Video has enough bandwidth but will it attract RF too much or don't filter enough?

 

This device from RDL found quickly, but it says it reshapes S/PDIF data, and works from 24V dc, real high voltage ?

 

[sandyk]

2 hours ago, Ralf11 said:

but they may not have done so...

 

He presented a good check list:

1. Jitter, timing issues,

2. quality of the power supplies

3. not sure what was meant by "system noise"

and there may also be 4. noise from various processes in the computer

 

I won't claim they are always an issue, but won't claim they are never an issue either.  One needs to measure.

 

 Good luck at getting confirming measurements at the Analogue Output of a DAC though.

 Yes, noise from various processes in the computer can also be an issue, which is why many reduce the number of non essential programs running, either manually or using Fidelizer etc.

 (Running in Safe Mode can also help here, but isn't so easy with Windows 10.)

It's also a good idea to disconnect the cable to a Broadband Modem if used  for optimum results.

[marce]

7 hours ago, sandyk said:

 

 Both Digital Audio and Digital Video are affected by Jitter, timing issues, the quality of the power supplies, and System noise going along for the ride when they become an ANALOGUE replica of the original binary signal when exported to the DAC/receiver for reconstruction.

 

 The link to the thread attached which is possibly the largest thread in the history of C.A. (494 pages) will also show that numerous other C.A. members do not agree with you either.

https://www.computeraudiophile.com/forums/topic/30376-a-novel-way-to-massively-improve-the-sq-of-computer-audio-streaming/

 

However you of course know better, so I have no interest in  discussing this further and will not be doing so in this thread..

A thread where science cannot be discussed and the laws of physics are banned...

[marce]

7 hours ago, fas42 said:

While people want to cling to the glorious belief that there are zero pathways for analogue areas of the playback chain to be affected by electrical behaviours on the "digital" side, the arguments will continue ...

Jeez give it a rest... there has been a plethora of information regarding EMC, its a well known and studied subject... and has been for many years.

[Teresa]

8 hours ago, KeenObserver said:

...Let me see if I can understand this.  Even though trillions of bits of data are ACCURATELY sent around the world every day,  we cannot send music bits accurately?...

 

With error correction music does send the bits accurately most of the time. The difference with data is audio reveals jitter, timing issues, and noise adversely effecting music files as others have noted. With a text file, the timing of letters appearing on the screen does not matter as long as they appear in the correct order, also I will never hear noise in a text file. So how can anyone compare a text file to a music file?

[marce]

Jitter and timing issues at the point of conversion really should not be a problem today... Noise we have known about for years...

As I sit here I am looking at what I am laying out now and comparing it to what I was laying out 30 years ago... and then wonder why jitter is an issue for basically what is slow data conversion, audio. As to noise, well we have known about that for a year or two... I do think that in some ways the ludditian attitude of some audiophiles regresses the field of hi-fi music reproduction...

[asdf1000]

3 minutes ago, marce said:

As to noise, well we have known about that for a year or two...

 

Can you expand on this?

[Jud]

17 minutes ago, Em2016 said:

 

Can you expand on this?

 

I think it was a bit tongue in cheek.   

[Jud]

9 hours ago, KeenObserver said:

Those music bits are rascally little devils.  Got a mind of their own.

 

There are some slightly different concerns with music playback, as we know.  Doesn't mean of course that it isn't subject to all the same physics, measurement, etc.

 

What I mean by slightly different concerns is that with other digital operations, as long as noise and jitter, for example, aren't at a level to cause actual dropouts, we're good enough.  So levels of noise or jitter induced distortion in the signal that can be perfectly acceptable in other operations may not be so in music playback.

 

On the other hand, as @marce says, digital audio signals are at relatively low data rates.

 

So yep, there are some differences, some of which tend to make digital audio easier to work with, others that introduce concerns at noise and jitter levels that wouldn't be issues in other applications.  But overall, these are quantitative rather than qualitative differences.

[marce]

1 hour ago, Em2016 said:

 

Can you expand on this?

Well I've been working in electronics for over 3 decades and we have known about the noise electronic systems generate since before then, so its nothing new... Plenty of info out there on noise mitigation and filtering as well, Henry Ott, Ralph Morrison, Keith Armstrong amongst others have written about it....

[marce]

And we have known about SSN for years, that simultaneous switching noise, the noise digital circuits generate when they switch due to the parasitic elements in the circuitry re-acting to the high Di/Dt nature of digital switching... as well as other sources of noise so its nothing new and can be solved for sensitive instrumentation, so why not audio...

Are the demons as bad as made out? Not really but as many have a financial interest in combating these demons they are exaggerated as a problem some what.

[iaval]

11 minutes ago, marce said:

Well I've been working in electronics for over 3 decades and we have known about the noise electronic systems generate since before then, so its nothing new... Plenty of info out there on noise mitigation and filtering as well, Henry Ott, Ralph Morrison, Keith Armstrong amongst others have written about it....

Some noises are so impossible to filter out. Not necessarily audio-related noises. RFI from switching supplies, home appliances, computers, phones, gadgets, ... . There's no easy mitigation there, even bandpass filter sometimes only exaggerate the issue. 

 

Also ripple on DC rails is quite a challenge to filter out, with one of the better ways to deal with it is capacitative multiplier, which however runs at abysmal efficiency, negating main efficiency benefits of switching power supplies over linear ones. 

[Solstice380]

22 hours ago, The Computer Audiophile said:

I agree 100%. Wrought with potential errors. I think everyone should understand this no matter what side of the fence they are on.

 

Has there ever been a study, ABX or other, regarding auditory perception that completely eliminates personal bias?  

 

From the Cambridge English Dictionary:

 

perceive: verb [ T ] 

US  /pərˈsiv/

perceive verb [ T ] (THINK OF)

to think of something in a particular way: 

The way people perceive the realworld is strongly influenced by the language they speak.

 

What everyone makes of the “realworld” is the bias.