How drop an audio stream using avconv?

Looks like the option -an should do the trick. Just ran a file, confirmed, new file had no sound.

-an (output)
   Disable audio recording.

from http://manpages.ubuntu.com/manpages/precise/man1/avconv.1.html

To my understanding the -an parameter will simply drop audio from the output. If thats not what you wanted, then you need to use the -map command and specify how individual streams from different sources should be mapped to the output. The following example takes only the first stream from the first file (usually video) and audio from the second file.

avconv -i input0.mkv -i input1.m4a -map 0:0 -c:v copy -map 1 -c:a copy output.mp4