Originally Posted by arnyk
I'm wondering how many times I am going to be temped to rebut this obvious false claim?
I am familiar with nobody
who currently says that there are no measurable differences between digitial transports, except maybe people who seem to like to pose straw men, drag out stinky old red herrings, or just plain troll. ;-)
Well, you and I are not situated the same then as I know many who doubt such differences exist. Here is the OP from this thread:
Originally Posted by ptsawyer
Need help... am I imagining things?
I am currently running an infinity Primus setup with a Denon 2112CI. I have a Samsung BD-D5500 3D Blu Ray player hooked up via HDMI, as well as Pioneer 100 disc CD changer (circa 1998) hooked up via Optical.
Running either of these with an audio CD, in PURE DIRECT mode, should be identical
"Identical" in my book means they measure the same. I provided him with my article and he said: "Thanks for the link.... learning more and more every time I come here."
So clearly a misunderstanding was corrected.
And he is not alone. I bet vast majority of people think that. It simply is counter-intuitive that a digital system would behave in a non-deterministic manner this way. We are all used to copying files around on our computers and having no bits lost even when we use things like a USB drive with a cable in the middle. So it is natural for people to assume digital transports would act the same.
My article on digital audio variability and jitter
was originally published in Widescreen Review magazine. In 3-4 years of writing articles for them, none have generated as much interest and "aha moments" as that one has. I still remember emailing it to WSR and having the editor come back with shock at the data and revelations in the article. He wondered why no one else had talked about this before. Post publication I have received countless emails, messages and comments saying they had no idea there were such differences. So the data that I have points to exact opposite of what you are saying Arny.
Even the people who know there are source differences think such differences are filtered out before they get to the DAC. This again from the first thread between you and I:
Originally Posted by arnyk When it comes to issues like jitter on the audio signal, you can pretty much count on a HDMI-driven A/V processor doing the best possible job of buffering, reclocking and generally giving effective care to the audio signal.
As I showed in the article, what you describe does little to reduce the variations. Reclocking and buffering exists in AVRs yet HDMI often severely underperforms S/PDIF interface. So there should be no solace here and believing otherwise makes people think there is no measured difference.
It these assumptions that lead people into automatically assuming any listening tests showing differences in transports has to be an issue of testers head, than reality of product design
. I think people would be a lot more cautious if they knew a) that differences existed and b) they were of amplitudes that measurements show them to be. Please see more below.
Einstein said that insanity is doing the same thing over and over again, expecting a different result. Amir, how many times are you going to do this very same thing over and over again?
I wish we had converged here Arny so that I don't have to keep explaining the same thing over and over again. But we are not there yet. Earlier someone said, "So I feel that it's sort of like THD - sure we can measure it, and we can show that A has .00000001% and B has .0000000000000000000000000001%, but does this make B better in a way that us humans can appreciate?"
Here is a measurement of what 7 nanoseconds of jitter translates as seen in some AVRs:
So we have two distortion products at -80db. What is -80 db? If we convert that to a percentage we get 0.01%. And this is for just *one* distortion sideband, not the sum total as Total Harmonic Distortion (THD) computes. So we are not remotely talking about the tiny numbers mentioned above.
Indeed, a perfect 16 bit system will have a THD figure of 0.0016% -- still way less than above numbers. You can find amplifiers that do better than .01%THD. Who thought before this moment that their "perfect" digital source/interconnect causes more distortion than a power amplifier?
So yes, if we can get everyone to agree we will not have to discuss it. Something tells me there will be objections to this summary just the same, showing we are not there yet