yet neither of you said one word to refute what I said!
Ethan,
I apologize for any overly strong tone in my last post, but it was fankly an honest reaction. You have no idea how much I wrote and deleted and rewrote and deleted and... well you get the point
... before I finally posted it.
The source of my shock and awe was the fact that I have known you to be a very knowledgable and intelligent guy when it comes to stuff like acoustics and analog theory and such. I assumed in your continued attempts to debate digital minutia such as dither and jitter and such that you actually had a somewhat equal grounding in digital information theory as well. That post hit me like an IED that your fundamental understanding of how digital actually operates is frankly no where near your understanding of the analog world.
One thing I have come to slowly get through my admittedly thick skull in my time on this BBS is just how difficult it is for people who are not well-grounded in digital information theory to understand just how it actually works. It is so completly different from - and in many cases, counterintuitive to - the clasical analog ideas we have grown up with that it can at times be next to impossible to explain without having to teach the whole field from the very beginning. As long as my posts are, there is no way that those basics can be covered outside of an entire semester or two of explanation.
We see it everywhere from complete misinterpretations of just what Nyquist actually means, to the design mechanics of A/D conversion, to (as is ovbious by this thread
) what dither actually is and how it actually works. People keep trying to see it all in analog terms, and that just does not work.
I said it not to long ago in another thread, and I meant it seriously: people who try to understand digital mechanics in an analog mechanics kind of way wind up being just as confused and reaching just as wrong conclusions as people who try to understand quantum mechanics in a classical mechanics kind of way. They are entirely different worlds.
"Noise" in the digital context is an entirely different concept than "noise" in an analog context. They have the same name, and yes on a superficial level they have some related properties, but they are are really entirely different entities altogether. I have been trying to explain this over and over in this thread; I now understand why the relevance of that point has not gotten through; I can't get you past the "analog prejudice" in your mental picture of dither and how it works because you havent yet understood the fundamentals of the digital world. You keep trying to picture the inside of the digital atom in classical analog terms.
"Jitter" in the digital context is related to any kind of "flutter" in an analog context only extremely superficially; they are not anywhere near the same thing at all in their actual manifestations.
When I read that post where you're referring to "analog jitter", I have no idea how to respond. "Analog jitter" is an oxymoron, right up there with "colorless blue", "one hand clapping" or "scientific creationism". It demonstrates a complete disconnect between your concept of "jitter" and how digital jitter actually relates to the whole D/A process, because you're still picturing digital signal reconstruction from within an analog framework instead of a true understanding of digital information theory.
There are other problems with that paragraph; the idea of "analog dither" and the inside-out description of the "jitter/image focus" debate, for example. But just like with the rest, I hae no idea of how to even *debate* such points, let alone explain what is actually being debated unless or until many much more fundamental concepts of how digital works are covered and stipulated to first. That could take months. I'm not up for that.
G.
