cliveb;131259 Wrote: > I take it that this is a response to my second post in this thread.Sorry, it > wasn't aimed you particularly.
cliveb;131259 Wrote: > Further thought suggests to me that it's possible that the interpolation > may not actually generate any higher frequencies, and that upsampling > prior to the DAC is simply a digital alternative to the analogue > post-DAC filter used in a "traditional" D/A conversion process. If that > is the case, then I'm happy to accept that I have misunderstood what > upsampling is all about.Correct - although you still need the analogue > filter, it's much a much less demanding spec. cliveb;131259 Wrote: > But all the published material I've seen (which admittedly is on the > marketing side of things) from the likes of dCS seems to imply that the > purpose of upsampling is to "fill in the gaps" and allow a higher > sampling rate DAC to be used, with the clear implication that this > produces extra high frequencies and gives the eventual signal more > "resolution". > That's also correct on a simplistic level. However, the extra HF resolution that they're 'claiming' doesn't come from the interpolation process, it comes from being able to specify a simpler analogue reconstruction (post DAC) filter. So any improved HF response is as a result of not (analogue) filtering as sharply as you might have done with a NOS DAC. However, some NOS DACs don't bother with any post-DAC filters at all (instead relying on downstream bandwidth limitations in the speakers/human hearing). There's really no 'magic' to Digital Signal Processing - it's all maths. -- Patrick Dixon www.at-tunes.co.uk ------------------------------------------------------------------------ Patrick Dixon's Profile: http://forums.slimdevices.com/member.php?userid=90 View this thread: http://forums.slimdevices.com/showthread.php?t=26685 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
