Fascinating article. Is there any reason to believe that upsampling an audio file should produce a better analog signal than playing it at its native sample rate? I find that playing high quality mp3's through an upsampling DSP filter and a 24/192 DAC seems to produce a better listening experience. (As the article points out, this could be due to confirmation bias, or the filter making the music a tiny bit louder.) I…
No. Watch the Digital Media Primer and Digital Show & Tell, Monty (the article's author) explains how digital sound encoding works and why the analog signal will be reproduced beyond your ability to notice imperfections either way: http://xiph.org/video/
And that's for native 24/192, in your case since it's been upsampled the 24/192 signal can't have more information than the original 16/44.1, since that's all the information that went into it.