Yes any transformer will show the tilt as no transformer goes down to DC
BTW the frequncy of that square wave is just under 2MHz, is that correct?
Jan
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Lol, yes, iPhone and tapatalk thinks it knows better though..
You mean whoever wrote those apps didn't have a clue
jan
The shape of a square wave will not really tell you a lot, unless it is really bad or has non-monotonic rising or falling edges, and at SPDIF speeds with a correct rise time you should have no problems, unless there is excessive jitter, and only an eye diagram will give you that info.
There is NO correlation between what a square wave looks like and the resultant analogue sound field...
What it will show up is the standard of the path it has to travel from transmitter to receiver, and how well that is matched, signal integrity, but even then most low speed digital will happily get from a to b with no problems despite impedance mismatches.
Woops, we have just had an internet outage as I was editing, sorry about the dual posts...
There is NO correlation between what a square wave looks like and the resultant analogue sound field...
What it will show up is the standard of the path it has to travel from transmitter to receiver, and how well that is matched, signal integrity, but even then most low speed digital will happily get from a to b with no problems despite impedance mismatches.
Woops, we have just had an internet outage as I was editing, sorry about the dual posts...
It looks a little bit like a not calibrated 1:10 probe.
If you measure a iddle signal (silence or both channel driven with same sinewave) on the spdif, that is biphase coded, then maybe you see a quarter of the bitrate on the scope. (depends trigger, holdoff and also speed of the scope).
Is this a samplingrate of 48khz ?
With music or noise, maybe you can see every bit.
On the shape of the square wave you see the rise and fall and also big overshoots or unwanted feedback effects of the receiver, but usually not on a 50Mhz scope.
With the time delay function, you can also see something like a eyepattern.
But all this is no revealing of the audible effects.
If you measure a iddle signal (silence or both channel driven with same sinewave) on the spdif, that is biphase coded, then maybe you see a quarter of the bitrate on the scope. (depends trigger, holdoff and also speed of the scope).
Is this a samplingrate of 48khz ?
With music or noise, maybe you can see every bit.
On the shape of the square wave you see the rise and fall and also big overshoots or unwanted feedback effects of the receiver, but usually not on a 50Mhz scope.
With the time delay function, you can also see something like a eyepattern.
But all this is no revealing of the audible effects.
What makes you think that? We have no idea how the audio coming out of the DAC looks like.
I am very very sure, otherwise there would be numerous papers and documents available explain the phenomena, analogue digital conversion is not just for audio....
If the bits are getting through ie triggering the receiver and discounting jitter:
THER IS NO CORRELATION BETWEEN HOW A SQUAREWAVE LOOKS AND THE RESULTANT SOUND FIELD, it is the same with data for phase array radars and all other analogue/digital interfaces.
They are pretty much standard square waves, how would you correlate them to sound, how would they sound different, they are not analogue waveforms but digital, they represent a single bit, which will trigger the receiver.
What they do show, for the majority is to much initial current drive so to much energy going into the line and not being absorbed by the receiver, thus the ringing, this can be solved by slowing the rise time (series resistor at transmitter) or some parallel termination at the receiver to absorb the excess energy.
I would be interested in your theory of how those SW. illustrated could sound different.....
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I'm with this:
Your DAC it is (opticaly) isolated? If you do don't have a very god isolation of GND and signal between digital source and analog side of the DAC, any changing even in DC resistance of cable can change the sound.
With a god isolation (opticaly let's say) I bet that you will hear only subjective differences for allmost all cables.
You need an eye diagram on a high speed oscilloscope to check the signal integrity.
Your DAC it is (opticaly) isolated? If you do don't have a very god isolation of GND and signal between digital source and analog side of the DAC, any changing even in DC resistance of cable can change the sound.
With a god isolation (opticaly let's say) I bet that you will hear only subjective differences for allmost all cables.
Maybe a short rise/fall time is better for less jitter and you can hear this. But we must look not only at the risetime but also on the level.
Depends on the input stage, but normally, a input comparator vary the propagation delay skew with the input fall/rise time and this can cause additional jitter.
You can see and hear this on higher bit rates with long cable, but this is extreme.
Hope that the jitter eliminator works always well.
Depends on the input stage, but normally, a input comparator vary the propagation delay skew with the input fall/rise time and this can cause additional jitter.
You can see and hear this on higher bit rates with long cable, but this is extreme.
Hope that the jitter eliminator works always well.
How would changing the DC resistance change the sound, we are talking about a digital SPDIF signal down a cable, how explain...
this is starting to get in to the 'Outer Limits' realm of digital audio....
Rise times of signals should be chosen to match the fundamental clock frequency, to fast a rise time is as destructive as to slow a rise time...the shape of the wave within certain limits does not matter, as long as the switching levels are maintained and periodic drift is minimised. What ringing does do is stress the silicon due to the extra energy being dissipated.
We are talking SPDIF here and not DDR3 interface...
Again looking at the square wave will not give any indication of sound output (again as long as the wave is fulfilling the data transfer), look at them all day long and there will be no correlation.
If ya wanna learn some basics of Signal Integrity have a look at:
https://www.sigcon.com/
http://bethesignal.com/
http://www.hottconsultants.com/
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@marce
Yes, those waveforms looks pretty much standard digital.
But, wait a second....you have to transmitt signal from RX to TX through cable,....and cables are analog medium,.....you have to recover an embedded clock,.....and clock extraction is analog process....
Are we still talking about standard digital signal, where only 0 and 1 matters?
Or are we talking about RF analog signals, whick looks like digital waveforms and where RF rules applies (impedance matching, terminations, reflections, attenuation, bandwith limitations,.....)?
We agree, those waveforms will cause more or less different sound, is this correct assumption? Or will they all sounds the same?
But WHY will they sound different, if this is digital signal, where only 0 and 1 matters?
After few years of playing with S/PDIF signals and listening simultaneusly, different waveforms and different sound will start to correlate and signals with HF peaking will sound different from signals with limited bandwith and rounded edges.
Or my ears are just playing games with me
Yes, those waveforms looks pretty much standard digital.
But, wait a second....you have to transmitt signal from RX to TX through cable,....and cables are analog medium,.....you have to recover an embedded clock,.....and clock extraction is analog process....
Are we still talking about standard digital signal, where only 0 and 1 matters?
Or are we talking about RF analog signals, whick looks like digital waveforms and where RF rules applies (impedance matching, terminations, reflections, attenuation, bandwith limitations,.....)?
We agree, those waveforms will cause more or less different sound, is this correct assumption? Or will they all sounds the same?
But WHY will they sound different, if this is digital signal, where only 0 and 1 matters?
After few years of playing with S/PDIF signals and listening simultaneusly, different waveforms and different sound will start to correlate and signals with HF peaking will sound different from signals with limited bandwith and rounded edges.
Or my ears are just playing games with me
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After few years of playing with S/PDIF signals and listening simultaneusly, different waveforms and different sound will start to correlate and signals with HF peaking will sound different from signals with limited bandwith and rounded edges.
Or my ears are just playing games with me
The circuits between the S/PDIF input and the analog output are so complex and varied that there is no way you could have any simple rules stating "an input wave that looks like this on the scope will sound like that". Transmission errors and jitter will have a very different effect on the sound depending on the construction of the DAC.
THOSE WAVFORMS WILL SOUND THE SAME.....
It is digital signal transmission, they will all sound the same...
Read the posted links on digital signal transmission.
Cables are neither analogue or digital, they carry a signal from a to b and are engineered to carry the signal with the minimum of interference or change to the original signal, not magic, just basic signal transmission and physics.
No they are not RF they are digital, digital design rules apply.
And yes your mind is playing games with you.
I don't know how often your are involved with getting digital signals from a to b.
Some audiophiles do like to equate digital with analogue, maybe if the read the fore-mentioned digital design gurus information and books and looked at digital engineering and design maybe we could dispel some of these myths and replace them with cold hard physics.
It is digital signal transmission, they will all sound the same...
Read the posted links on digital signal transmission.
Cables are neither analogue or digital, they carry a signal from a to b and are engineered to carry the signal with the minimum of interference or change to the original signal, not magic, just basic signal transmission and physics.
No they are not RF they are digital, digital design rules apply.
And yes your mind is playing games with you.
I don't know how often your are involved with getting digital signals from a to b.
Some audiophiles do like to equate digital with analogue, maybe if the read the fore-mentioned digital design gurus information and books and looked at digital engineering and design maybe we could dispel some of these myths and replace them with cold hard physics.
get writing your thesis there is a Nobel prize in this for you, because in all other areas of digital/analogue design including most non-audiophile analogue/digital this is not so, so you have probably made one of the most important discoveries in recent times, personally I find it rather ridiculous and up there with the weirdest far out audiophile myths.
NOPE, as I said write a thesis you will get recognition...
The square wave represents the bits that will cause the receiver to switch at a certain level, that's it the wave does not exist in any form after that, if what you say is true, where are the technical documents where is the research.
Please provide some proof of this world shaking claim.
Digital to analogue basic conversion is the same what ever the circuit or DAC device used.
This is quite simple and nothing mystic: if the digital source do not have a good isolation like optical (the transformer can couple some noise), then you will have more or less a ground loop (like DC resistance of connecting wires) and any variation on this ground loop will influence the analog side of DAC (assuming no isolation).
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cable carrying digital signal to DAC, like all cables it can couple noise, measure the system and decide if this is a problem. But just referring to a cables DC resistance is simplifying things a bit. Noise depends on the source, the environment and other factors and can be solved by engineering a solution, and if changing the cables DC resistance changes the sound then your system is crap and needs sorting out.
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