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BlueFox's picture
Last seen: 3 years 1 week ago
Joined: Jul 24 2012 - 12:10am
Can downloaded files pick up jitter as they traverse the Internet?

It is already known that a music file can have jitter introduced into it as the bits are reconstructed due to slight timing errors in detecting where it transitions from a 0 to a 1, or from a 1 to a 0. This has me wondering if a downloaded file can suffer the same fate. The packet will undergo a number of transitions such as electrical to optical to electrical as it travels through the net. When it hits a router it will go from Ethernet to an internal format and back to Ethernet as it leaves the router. While the CRC will be correct it certainly seems possible jitter can be introduced into the file.

At least that is my current thinking, but I have no idea how to test it. Maybe if there were a way to get the HD file on a USB drive and compare it with test equipment (and listening) to the downloaded version that might be a method.

Any ideas? Does this make sense?

John Atkinson
John Atkinson's picture
Last seen: 38 min ago
Joined: Nov 7 2010 - 3:31pm
Re: Can downloaded files pick up jitter as they traverse the Int
The short answer is no, if you are downloading the files to local storage before playback but perhaps yes if you are streaming the data.

John Atkinson
Editor, Stereophile

michael green
michael green's picture
Last seen: 3 weeks 4 days ago
Joined: Jan 10 2011 - 6:11pm
mechanical conduits

Hi Blue

Any time you have a physical conduit carrying the signal there is change. At least this has been my experience in listening.

michael green

rbbert's picture
Last seen: 3 years 4 days ago
Joined: Oct 18 2009 - 10:22am
FLAC has a built-in checksum

As JA says, if you are downloading files you can ensure they are bit accurate simply by decoding the FLAC file, which process will ensure that the resulting WAV or AIFF file is identical to the checksum data stored in the FLAC shell