darrenyeats wrote: > When the sampling rate is increased, "images" of the original signal are > created at higher frequencies - the up-sampling (anti-imaging) filters > are intended to remove these. Any filter placed after the DAC > up-sampling stage could do a similar job in principle. In fact NOS DACs > rely on the fact that amps, speakers, ears - all after the DAC output - > are natural filters. And even up-sampling DACs use a combination of > digital and analogue anti-imaging filters. > > But if the filter is applied (e.g. with equaliser in a computer player) > before up-sampling, it won't be doing the same job. > > You can -up-sample and filter- on a computer, and pass the music at the > higher sample rate to the DAC. This could avoid a stage of up-sampling > and filtering in a typical DAC (but with typical DACs there is more than > one stage).
This is conditionally and not uncommonly false. If the DAC is operating with an excessively high sample rate as is common with audiophiles, say 96 KHz and above, then an anti-imaging filter further down the signal chain operating at a more sane design frequency such as 44 KHz can still remove any audible imaging. However, upsampling is generally just superstitious audiophile wheel-spinning. Once certain kinds of mistakes are made, they cannot be fixed with subsequent processing. Audiophiles have proven their inability to hear what they claim as shown by their willing acceptance and adulation for so-called high resolution recordings (SACD and DVD-A). As of about 2008 about half of them or more had low resolution recordings in their provenance, and the inherent audible problems with resolution and bandpass built into in them cannot be overcome with post-processing. No audiophile or audiophile reviewer that I know of reported thins in the usual Golden Ear publications. If one of the so-caled NOS DACs is followed by a properly-designed reconstruction filter, the intentional design error that they embody, which is the elimination of said filter, can be overcome. ------------------------------------------------------------------------ arnyk's Profile: http://forums.slimdevices.com/member.php?userid=64365 View this thread: http://forums.slimdevices.com/showthread.php?t=106979 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/audiophiles
