bpa wrote: > I agree with you totally on the practicality but just trying to answer > questions people ask. Why are 192KHz DAC made in the first place ?
Because DACs do upsampling internally, which in turn makes the post DAC filtering (which used to be done in analogue) much simpler. The hardware has to filter out all frequencies above half the sample rate to avoid aliasing noise, if the DAC is done at 44.1 or 48 KHz then this needs to be a very sharp edged filter (which is hard to make) to both block the unwanted noise while not losing audible frequencies. If the DAC upsamples internally, then the noise that needs to be filtered out has doubled in frequency but the audio you are trying not to lose has not, so suddenly the filter can be both much simpler (and cheaper) and also higher quality since it has a much simpler job to do. So far so good, but then someone decided if the DAC can upsample internally it can also be fed that high a sample rate from outside, then marketing got hold of the idea without understanding sampling theory (hence all those fictitious stair step pictures of DAC outputs) and we find ourselves where we are now. ------------------------------------------------------------------------ Owen Smith's Profile: http://forums.slimdevices.com/member.php?userid=42371 View this thread: http://forums.slimdevices.com/showthread.php?t=104383 _______________________________________________ discuss mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/discuss
