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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
audio2design
1,351 posts
 
The output of a DAC sans built in filter or external filter will be a stairstep. I can't think of a DAC in audio that is not convert and hold.


gs5556, that is a conceptual answer, not the reality of an actual DAC. Not many (any) DAC have an impulse function output.
jjss49's avatar
jjss49
6,612 posts
 
google "digital to analog conversion' and 'nyquist theorem'
fuzztone's avatar
fuzztone
5,643 posts
 
PCM stairstepped.
DSD not.
But you usually have to spend up to play pure DSD. Most systems use DOP.
audio2design
1,351 posts
 
From a practical standpoint, depending on the Reconstruction filter, whether there is one or not, DSD will still stair step because it is reproducing PCM values.
audio2design
1,351 posts
 
I was thinking when playing PCM through Sigma Delta but pure DSD path would look steppy but much smaller steps since still discrete in time.
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