darrenyeats;695330 Wrote: > Despite my doubts and musings yesterday, I don't think so. What is the > difference between a sine wave and a square wave at -90db in 16 bit? > None. A 16/44 DAC should smooth this analoguely (I think this sinc > function thingy is about this). A 24/96 DAC would upsample and > interpolate the data points of this tone into a smoother shape (because > the DAC assumes it's NOT a square wave - a square wave would require an > infinite series of harmonics yet we know the data is band limited to > satisfy Nyquist). > > Please see here: > > Darren
That miska stuff is bollocks. he's using audacity plots to try to prove his incorrect point. Audacity has major bugs int the way it renders waveforms on screen. If you put a real oscilloscope across a DAC you get to see the truth and it doesn't look like ANY of his plots!!! A 10khz sine wave looks very fine to me coming out of my DAC, regardless of sampling rate or bit depth (assuming that it's level is NOT -90dB!) DACs don't have intelligence and don't make contextual judgements. They just do what they do. With a one bit symmetric waveform you can keep the bit on or turn it off. If you keep it on for a few samples then off for the same number of samples you have an approximation of a square wave ( which of course the analogue parts of the DAC cannot reproduce properly because of filter ringing). If you turn it alternately on or off for a single sample you get the approximation of the sine wave...which the filter will smooth... If you only have one bit there isn't really much else you can do with it! - and the DAC cannot have any understanding of what you were trying to do with it :-) -- Phil Leigh You want to see the signal path BEFORE it gets onto a CD/vinyl...it ain't what you'd call minimal... Touch(wired/W7)+Teddy Pardo PSU - Audiolense 3.3/2.0+INGUZ DRC - MF M1 DAC - Linn 5103 - full Aktiv 5.1 system (6x LK140's, ESPEK/TRIKAN/KATAN/SEIZMIK 10.5), Pekin Tuner, Townsend Supertweeters,VdH Toslink,Kimber 8TC Speaker & Chord Signature Plus Interconnect cables Stax4070+SRM7/II phones Kitchen Boom, Outdoors: SB Radio, Harmony One remote for everything. ------------------------------------------------------------------------ Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85 View this thread: http://forums.slimdevices.com/showthread.php?t=94054 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/audiophiles
