[sdiy] Digital audio demo on Youtube

[rburnett at richieburnett.co.uk]

Monty's statement and Achim's reply are true.  The stair-steps are an 
artifact of the DAC designer's choice to use zero-order hold in their 
DAC.  The stair steps are not part of the digital sampled signal, they 
are the result of a design decision, just like the alternative options 
of linear interpolation, sinc interpolation, etc...

Zero-order hold distorts the wave shape, does very little to remove the 
high-frequency sampling images from the output, and also causes 
significant attenuation of the treble frequencies in the audio.  That's 
why consumer and professional audio DACs no longer use ZOH today.

-Richie,



On 2014-02-18 17:18, MTG wrote:
> I don't think this guy does any favours at 8:00 when he says that
> Wikipedia is confusing, "the stair-steps aren't really there". All the
> (non-1-bit) dacs I see in these old synths generate pretty visible
> stair steps... plus I'm sure there are lots of "control" dacs on the
> planet so we shouldn't just assume every DAC is on a PC motherboard
> (for instance).