I think that speculating on motivations is not terribly productive.
I'm not interested in converting the faith-based, but it would be nice to see some similar stuff to what Pano showed as effects of modifications rather than continually citing the same evidence that's used to justify beliefs in alien abductions. There are many more people who read than post and it would be nice to get actual data out for general edification.
Yet one more unsupported claim.
The latter part of your sentence turns out to be correct - I've been defending nothing here all along. The truth is rather like 'The Hound of Heaven' - rather than needing any defense, its rather people that wish defense from it.
Thanks JR. I miss the old one, too. Will go back to it soon. The current is Leon Trotsky, who looks a lot like me. Or vice versa. I used him as the welcome animation on my old Siberian.tv website. (motorcycle racing)
audivi, postulo, pluo (I heard, I measured, I posted) et tu?
So far just the first one. The other two to follow along in due course when I'm able to correlate measurement with listening to my own satisfaction.
"I think that speculating on motivations is not terribly productive." You said a couple of posts ago? Does this only apply to others speculations?
I want to find out if your tests are sophisticated enough to reveal the differences I talked about or are they just a red herring (I might as well throw some fish around as everybody else is & the smell is getting rank
). I still doubt your tests would reveal anything usefulI have SPDIF plots of before & after the modifications that show:
- the modded JKHiface has a cleaner SPDIF waveform - less perturbations!
- the modded Hiface has a faster rise time from about 6ns to about 4ns - this should make for a more precise transition time!
(As an aside - I also have scope shots with the RF attenuators in-line & the SPDIF waveform is almost perfect.)
However you interpret these shots they show a cleaner, better constructed waveform with a faster rise & fall time. For those who know anything about digital signalling, the results are self-evident.
I don't know why you rejected these as, to me, they are the best evidence of the changes wrought by a change in the PS to the unit. They are taken at the output of the unit that was modified, not downstream form that unit after it going through a number of unknown devices (DACs) & power supplies, all of which have the potential to mask the effects of the differences. (What DAC were you intending to use for your analogue tests?)
Remember this all stems from another thread about providing an external 5V supply to the Hiface instead of the USB 5V.
http://www.diyaudio.com/forums/pc-based/170972-modifying-usb-cable-supply-5v.html
A number of posters barged into that thread saying that it was a waste of time & would make no difference. I cited my & others experience of my PS mods & finally mentioned these plots as proof that changing the digital PS has a significant change to the digital waveform. This evidence was rejected & the argument changed to wanting proof that it made a difference to the sonics (not what the original claim was at all - the claim was "bits is bits, the USB 5V is designed for & good enough for the job; fundamental theories of digital electronics", etc.)
I find this changing of the goalposts a trick used by those who are only interested in winning the argument & not really seeking any truth!
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Panomaniac, thanks for posting these results - much appreciate the time you have taken to find them & post them. I wish that they had shown changes on the analogue out as a result of changes to the digital side of the unit - this would have been proof that measuring this is possible.
What you did was put in a transformer instead of the stock output stage & then saw a difference in the spectrum! I would have been surprised if you had not seen a difference in the spectrum! What was the stock output stage? An op-amp or active devices? Of course you'll find differences
Do you think that these results show the test is sophisticated enough to capture what we are talking about?
What you did was put in a transformer instead of the stock output stage & then saw a difference in the spectrum! I would have been surprised if you had not seen a difference in the spectrum! What was the stock output stage? An op-amp or active devices? Of course you'll find differences
Do you think that these results show the test is sophisticated enough to capture what we are talking about?
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I'm no expert in digital audio but one thing I can also see in these shots after having studied them a bit more is possible evidence of jitter reduction:
- on the stock Hiface the rise-time plot shows a couple of subtle perturbations in the trace when it is in it's critical phase i.e. during rise time & fall time - this is when transitions are sensed . This isn't a straight clean line from High to low but shows a couple of deviations from straight. These deviations effect the timing of when the transition is sensed i.e. jitter!
- the modified Hiface shows a steeper rise time line with no perturbations ie. there is no timing deviations between cycles (in this area anyway).
I would be happy for anybody to perform eye-pattern tests on these units to pin down possible jitter & other differences between stock & modified units.
Again I will repeat, I doubt the analogue tests are capable of revealing anything worthwhile. I'm open to be proven wrong by being shown evidence of this but so far no evidence has been presented here!
- on the stock Hiface the rise-time plot shows a couple of subtle perturbations in the trace when it is in it's critical phase i.e. during rise time & fall time - this is when transitions are sensed . This isn't a straight clean line from High to low but shows a couple of deviations from straight. These deviations effect the timing of when the transition is sensed i.e. jitter!
- the modified Hiface shows a steeper rise time line with no perturbations ie. there is no timing deviations between cycles (in this area anyway).
I would be happy for anybody to perform eye-pattern tests on these units to pin down possible jitter & other differences between stock & modified units.
Again I will repeat, I doubt the analogue tests are capable of revealing anything worthwhile. I'm open to be proven wrong by being shown evidence of this but so far no evidence has been presented here!
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Well if there is a jitter difference, that can be measured in the analog spectrum coming out of the DAC. But remember that most designers go to great lengths to make DACs insensitive to jitter, so on a very good DAC the jitter difference would not show up. You could say that if the jitter difference shows up and is actually audible you should get a better DAC
jd
Well if there is a jitter difference, that can be measured in the analog spectrum coming out of the DAC. But remember that most designers go to great lengths to make DACs insensitive to jitter, so on a very good DAC the jitter difference would not show up. You could say that if the jitter difference shows up and is actually audible you should get a better DAC
jd
So, on the one hand you are saying that the low jitter signal I'm suggesting is responsible for this improvement in sound is going to be negated by a good DAC & you still think that the analogue output from a DAC will show the difference between two SPDIF signals one lower jitter than the other? Can you please explain this logic?
That's what you get trying to explain subtle things in less than 10 words.
IF there is an audible difference, by necessity that would mean there is an electrical signal difference. IF that electrical signal difference is the result of differences in jitter, one way to measure it is in the spectrum of the reconstituted analog signal.
But the problem is that even if you have differences in jitter, you may not see them in the analog spectrum (and therefore not hear any difference) if the DAC is worth its money.
To add insult to injury, unless you did a statistically significant, well controlled test, it's not known whether there actually is an audible difference. Even with the very best intentions and complete honesty, having someone modify his equipment and then have him report the result is probably the most unreliable report you can get. No offense meant John, but that's reality for you.
The ugly truth is that the very first thing that should be established is that there IS an audible difference. Only then does it make sense to try to find a technical reason for it. Any other way is speculation and a waste of time.
jd
No offence taken but I & others have done numerous side by side comparisons of stock unit to modified unit - were they DBT, no - there is absolutely no need, the difference in sound is so glaringly obvious & noticeable from the first couple of notes. No offence but I already have given this proof with links to the reviews. Have you read any? Anecdotal, yes & not worth a damn according to those who have never heard the unit - say this to one of the people who have a unit & they will laugh at your stupidity in requiring DBT.That's what you get trying to explain subtle things in less than 10 words.
IF there is an audible difference, by necessity that would mean there is an electrical signal difference. IF that electrical signal difference is the result of differences in jitter, one way to measure it is in the spectrum of the reconstituted analog signal.
But the problem is that even if you have differences in jitter, you may not see them in the analog spectrum (and therefore not hear any difference) if the DAC is worth its money.
To add insult to injury, unless you did a statistically significant, well controlled test, it's not known whether there actually is an audible difference. Even with the very best intentions and complete honesty, having someone modify his equipment and then have him report the result is probably the most unreliable report you can get. No offense meant John, but that's reality for you.
The ugly truth is that the very first thing that should be established is that there IS an audible difference. Only then does it make sense to try to find a technical reason for it. Any other way is speculation and a waste of time.
jd
So can we get past the "is there an audible difference" - we are not talking about subtle here - it's so damn obvious! ( I know you are going to use this phrase to prove your point but read on)!
Now you say that a good DAC is going to manipulate this jitter by re-clocking or time domain tricks (Sabre) so why would you want to measure this manipulated signal when you should be looking at the signal straight out of the modified unit? Have you taken all the variables into account before you get to the analogue signal out? Cables, terminations, PS of the DAC, Output stage of the DAC. DAC chip itself. All of these can & will introduce their own distortions/jitter.
Are you really telling me that a straight measurement of the signal coming out of the Hiface is a worse measure of what's going on & you would prefer to measure a signal that has gone through these following stages with all of their variables? I find this a very unscientific & illogical approach
Just because you have a mantra "If it can be heard, it can be measured"?
Again, I repeat, so far nobody has shown me plots to prove that this is the case & shown that anything subtle that we are talking about here can be measured. If it's all that simple why doesn't somebody produce these plots of THEIR analogue out that they have done showing differences in jitter measurements - not a reference to published papers showing simulations?
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John I perfectly see your points, but you can't expect people to immediately drop everything they are doing and try to produce measurements and plots or get the same DAC you have and embark on an extended listening test. Does that mean we should shut up? Not at all in my book.
You yourself mention lots of factors that can impact the audible result - cables, re-clocking, the works. Yes there is a difference in rise/fall times. Is that responsible for the audible difference? IS there an audible difference? Don't know. Does that mean it is my responsibility one way or another to proof or disprove it? Not at all.
You make a claim, I (and others) point out that there are a lot of uncertainties before you can reliable establish a link between cause and effect, especially when the effect itself is not unchallenged to begin with. Note that your claim is very strong, unquestioningly, while the sceptics are just that - nobody says that it is inaudible, or that there is no audible effect. Just that any effect and any cause cannot be linked based on what we know.
I'm sorry if that sounds a bit too formal for your taste but we ARE trying to be clear to each other I think.
To sum up: you may be on to something, or maybe not. Based on my experience and what I know, I doubt it. But I don't know for sure.
I CAN be convinced with a lot of more strict evidence, but I accept that you don't want to go through all that effort; after all, YOU are convinced already
jd
Let's face it jk, you can insist that this is the case, but the evidence (all the rest of your posts taken as a whole, and the tone with which you have addressed members) suggests that this is just a piece of insincerity, calculated, in fact, to inflame hostility. You imagine we're idiots, but we see right through you. You have accused people of being interested only in winning the argument, when it is plain as day that it is you who are only interested in winning the argument. Nobody reading this thread is likely to believe anything else. You like to portray yourself as a seeker after truth, but basically you come across as a guy who resents the fact that there are a whole lot of people here who have forgotten more electronics than you'll ever know (at this rate). People who have developed a gut feeling for engineering which means that they don't need to see a measurement to know the score and who aren't going to take the time to perform one for some intransigent novice.
This 'modification' is trivial. Of course it's trivial. You don't have the skills to invent a significant modification, and so you put all this energy into advocating what you've got. The simple fact is that electronics is difficult. You can't luck into a significant discovery, and all the rest of us who have put in the work know this. There are just too many engineers out there working their balls off to get noticed for this not to have been extensively explored on more than one occasion.
Why not just stop for a minute, and try to appreciate the impression you are creating. You're not coming across as likeable or helpful, or even brusque but knowledgable. On the contrary, your behaviour is hateful and destructive.
w
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No I don't expect people to drop everything and attend to this but I have been told all along that it's a 15 minute job - I can only believe this as true?
No I don't think it's your responsibility. I was really just questioning the validity of the analogue out tests as a reasonable scientific approach when there are so many variables in the way! That's what the title of the thread is & we happen to be focusing on this one specific device - I guess it's as good a way of avoiding abstractions as any.
Appreciate your clarity! I'm saying I will submit the unit to testing - eye patterns, etc - tests which have some chance of showing that there is a difference between stock & modified. I will not submit it to a test that nobody is willing to stand over & that has so many variables as I listed above.
My reluctance is because I don't believe the test has validity for al the reasons I mentioned. If people then accuse me of "having my bluff called" or being scared of the truth then I don't find them credible. If people keep pushing for this test & yet won't produce evidence of it's validity & then claim that I am dodging & avoiding, I distrust their credibility.
I have offered to provide units, preferably to somebody in EU (for customs reasons) to perform listening & eye pattern tests or indeed full blown jitter tests if they have the equipment. How these results translate into audible sonics is a whole can of worms & not something that anybody here has been able to provide examples of!
Do you want to hear/test it? You are in EU, right?To sum up: you may be on to something, or maybe not. Based on my experience and what I know, I doubt it. But I don't know for sure.
I CAN be convinced with a lot of more strict evidence, but I accept that you don't want to go through all that effort; after all, YOU are convinced already
jd
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I do, yes. However I doubt that any measurement will ever satisfy your needs. You appear not to be interested in proof at all, but something else entirely.
Bottom line: This thread is a violation of the rules on more than one account. Mostly this one:
The Rules said:
This is clearly a continuation of your other thread and should not have been allowed in the first place. You have been offered well reasoned help from very technically competent and friendly forum members which you have dismissed at every turn. This is insulting to the members of this forum. It is also trolling. See rule #2
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