Phil Leigh wrote: > > darrenyeats wrote: > > > > I was thinking of these (figure 5 in each case): > > http://www.stereophile.com/content/b...r-measurements > > http://www.stereophile.com/content/s...r-measurements> > > ... It's not clear to what Stereophile think these measurements prove > in terms of sound quality? - my guess is nothing, so they are only > meaningful as an engineering benchmark in comparison with other DACs.
Apologies for the belated response. I offer this measurement, of an undithered 16-bit tone at exactly -90.31dBFS, because it easily reveals DAC linearity problems. Perhaps to simplify overmuch, in the 2's-complement encoding used by16-bit LPCM, the two transitions shown, from the zero line to +1LSB's voltage and -1LSBs voltage, actually involve maximally asymmetric bit changes in the digital data presented to the DAC: one from all bits = 1 to all bits =0; the other from all bits off to just the LSB = 1. The fact that with a good DAC, the voltages are equal and the waveform is symmetrical tells you that the summed errors in the 15 MSB transitions are very much lower than the LSB transition, which is what you want. With the vast number of DACs now sigma-delta types, this test of obsolete, But I still include it because it also shows you at a glance how high above the DAC's noisefloor the LSB transition lies. John Atkinson Editor, Stereophile ------------------------------------------------------------------------ Stereoeditor's Profile: http://forums.slimdevices.com/member.php?userid=40770 View this thread: http://forums.slimdevices.com/showthread.php?t=94054 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/mailman/listinfo/audiophiles
