1s are 1s, 0s are 0s, right?

I am quite happly with my system's audio quality and I don't feel the urge to spent $6000 or so to find out if an esoteric player would sound better. (I have other interests to spend money on).

It's true that my experience with digital communications is in the context of very high-tech military equipment (missile guidance systems) and the techniques that we use may not always be utilized in audio equipment, although I can't see why not since the cost of doing things right would not be great.

In summary, to address the wrong ideas that I hear most often...

digital pulse distortion, be it pulse shape due to line reflections, or timing (jitter) should have no effect.

Error correction is not bad. The purpose of error correction is not to correct errors. It is to permit higher bandwidth communications by operating the hardware so fast that (correctable) errors do occur. You give away, say 50%, of your bandwidth to redundancy, so that you can run, say 5 times, faster.

D/A non-monotonicity would cause audible distortion, but I am not aware of this being a problem with modern electronics.

Eldatford, I didn't mean to suggest relative value and how you should spend your money.

A digital signal is still a signal, that is, a time-variable voltage/current presence on the wires. I think here is an important distinction: If the device interpreting the signal treats it as just a sequence of data-bits, buffers it, and then creates an analog signal based on its own internal clock, then sure, 1s will be 1s and 0s will be 0s. But if the time variation of the original signal has an effect on how the device responds, the that signal is essentially sending extra analog information to it as well.

nonterminatingdecimal@hotmail.com....Exaxtly.

Well it seems we agree for the most part that changes in transport, cabling, etc, can/do have an effect on sound.

Just recently I purchased a Jolida JD-100. A fine sounding unit BTW. I had been using a Rotel RCD-971. Also a fine unit. Comparing the two, as transports only via a Theta DAC, clearly the Jolida had more firm and powerful bass.

I surmise that such variables as RF and other introduced "noise" could travel along with the data, thus "muddying" or confusing the DAC. Among many other plausible explanations.

I also surmise that there is a bit of "magic" involved as well. The end product(Stereophonic sound) truly is more than a sum of its parts(data). This occurs quite frequently in the world of Quantum physics, when the variables of time and space enter the equation. Clearly Stereophonic Music has these variables. Hmmmm.

It would be interesting to compile results from a Monophonic listening. e.g. Comparing qualitative differences of different cables and transports while listening to mono recorded sources played back in mono. I am curious just how profound or obscure differences would be in comparison to Sterephonic observations. A proof of the "magic" so to speak. Double Hmmmmm.

Just something to ponder.

Thanks to all the posters for a very enlightening read.