Originally Posted by NickMDal
If the CD is not sampled at a rate higher than 44.1, how can anything improve it other than by providing a cleaner signal to headphones (mobo noise)?
If the lossless rips are good quality, it would seem pointless to resample it higher.
Upsampling 44.1 kHz data by a non-integer multiple to, say, 192 kHz involves an interpolation step, so you won't get back the data that you put in. However, this also allows the use of a slow rolloff filter with less 'ringing' in the impulse response which some claim to be advantageous in terms of sound quality.
I would hesitate to judge a DAC simply on the basis of its digital architecture alone. Multi-bit ladder DACs can suffer from noise generated by drifting resistor values due to thermal loading and manufacturing tolerances (so I've read), however I'm unsure how the noise is distributed (I'm no digital expert) and I can't say for certain that I've ever listened to a true ladder DAC. Although Sapientiam eschews delta-sigma modulation, the current industry darling, the ESS Sabre32 Reference series DAC, bases its design on delta-sigma modulation with some noise-shaping tricks that they claim result in better sound. A presentation on the ESS Sabre DAC can be found here - http://www.esstech.com/pdf/noise-shaping-sigma-delta.pdf.
With respect to jitter, if you use a USB DAC that receives the data in asynchronous mode (e.g. DACs employing Wavelength Audio's Streamlength technology), it is largely immune to jitter as the data rate is controlled by the DAC and not the PC. The chief concern here is that your playback process receives a high enough priority within your OS that it isn't constantly interrupted by other running programs - this can result in drop outs and clicks / pops.
For a general introduction on how digital playback works, see:
For more on delta-sigma modulation, see:
For an interesting experiment on digital filtering, see:
Edited by yage - 12/31/13 at 8:39am