Originally Posted by vinnie97
Why, [does playing a FLAC music file via USB sound better than playing the disc the file came from] due to jitter introduced by the disk drive? Whether anyone can actually detect that (and not just believe they are hearing it due to bias, expectations, other uncontrolled variables, etc.) is another story.
Because music playback is ALWAYS a fully analog experience, even when it is the digital domain. Timing is hypercritical in music playback because music playback happens in real time (digital video is a series of still images, it's not "real time" motion). The effects of timing (uniformity of the space between bits, aka jitter) has been MEASURED and PROVEN mathematically. Timing errors in the low 100s of picoseconds produce measurable distortion in the analog output signal that is measurable... in fact, now we can measure both the jitter and the average timing variation (jitter) and correlate them. In addition in the 1990s, Prof. Malcolm Omar Hawksford Ph.D produced a mathematical proof that jitter in the low 100s of picoseconds produces predictable and measurable distortion in the analog music signal produced from a digital original. There appears to be SOMETHING about playing discs that never sounds quite as good as playing FLAC files made from the same discs. In fact, the best performing "disc transport" I've ever heard for playing CDs reads the entire disc before starting to play music. It holds the entire contents of the disc in memory at which point, the entire disc drive system is turned off. There are 2 reasons people convert entire music libraries into losslessly compressed FLAC or ALAC (or uncompressed AIFF or WAV files... the convenience factor is significant, no doubt, but those with good systems also notice that the music sounds better played from FLAC (or other lossless formats) files, even though computers aren't designed to be particularly low-jitter devices (nor do they need to be for most anything the computer does except play music). The issue is how big the differences are... they aren't the sort of differences you'd hear if you went to your best friend's home and after 10 years of hearing his system, he was playing music using a computer and FLAC files for the first time... chances are, you wouldn't notice or detect anything. But in YOUR system, given time to focus without outside interruptions, and decent (doesn't have to be grossly expensive) gear, it's not that hard to detect that playing a FLAC file sounds better than playing the disc. It's not a big slap-you-in-the-face improvement which is what throws a lot of people. It's not a microscopic difference either, but the difference is clearly more towards the microscopic end of the scale than the huge slap-you-in-the-face end of the scale. If you never sit and listen to music in a dark room for the sheer enjoyment of it, focused entirely on the music and how well (or poorly) individual elements are captured in the recording, the difference in playback quality would probably never be apparent to you.