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Basic technical question about digital source signals

Forgive if this is a stupid question, but the current thread about digital vs analog made me curious: if you look at an analog music signal you see (I think) summations of sine waves i.e. a signal waveform which is "smooth". I realize that there are many contributions to digital sound, but starting with the most basic, if you look at the output from a digital source e.g. on an oscilloscope, would it appear "smooth" i.e. has all the stairstepping that occurs when you convert digital to analog been smoothed out or would the signal appear jagged to some extent?

Thanks for your time.
berner99

Showing 2 responses by abraxalito

abraxalito
93 posts
 
Not really, it presumes that subsequent filters (mechanical limits in your speakers and your ear, which respond per F=MA; inherent limits in subsequent components) achieve he filtering. There will be no aliasing after the DAC. Yes, there could be HF noise residue; but hearing is highly attenuated above 22 kHz (if present at all) anyway.
Any presumptive filters won't be ones that do it by the book. HF noise residue most certainly will be present in the absence of an anti-imaging filter.

I would agree that subjectively, having images present is far, far preferable to having aliases.
abraxalito
93 posts
 
Not broken, a design decision to go NOS without a filter.

Its broken in the sense that such a design decision breaks the theory of digital audio. Just as a design decision not to band-limit the input breaks the theory.
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