Basic technical question about digital source signals

Read about Nyquist’s theorem.

Today’s samplers are even higher. Philips (and others) made a study of this during the 70s before the first CD’s were defined and introduced, and used thousands of people in listening experiments to reach a conclusion. No human can tell the difference between a properly sampled and then smoothed signal than an analog one. When the first CDs were introduced, neither the recording nor the playback equipment was as accurate as today. But in the past 10 years or so, the accuracy of ADCs and DACs have improved to an incredible point where noone will be able to tell the difference from the analog signal.

Extremely accurate instrumentation MAY be able to show a difference at a level hundreds of times more sensitive than the human ear. But that is a moot point since 99.9% of the humans will not be able to detect even one tenth of that difference.

Some on this thread will not accept what I am saying. They fall into that 0.1% category or are from another planet :-)

I don't think that is relevant to the discussion or that anyone was questioning what digital can or cannot do, though there was a side discussion on NOS DACs.

The relevance comes from the fact that the infinitesimally small jaggednesses that any instrumentation can see, if any, is irrelevant to the human ear.

In what context, with or without the reconstruction filter. Given there are implementations without one, you can't assume it will be there.