Mic volume.

[Paul]

You have yet to specify which distro you are using, however, the best
audio quality tweaks available are on SHR

http://shr.bearstech.com/trac/wiki/Tweaks

This has some values for mic levels to avoid buzzing which hopefully
you can apply to the distro you are using.

-- 
Paul
Email - paultsai at gmail.com

There were moments when he looked on evil simply as a mode through
which he could realize his conception of the beautiful.
Oscar Wilde - The Picture of Dorian Gray