GSM-noise "buzz" issue

Werner Almesberger werner at
Fri Sep 19 19:58:38 CEST 2008

Andrew Bruno wrote:
> So I ask OM... what's the average user to do? One that's not too steady
> with the soldering iron :)

I just wonder ... has anyone tried to make an audio plug that just
shorts MIC to GND ? Or, for simplicity, that just shorts all four
contacts to each other ? I think such a "headset suppressor" could
be made fairly flat, maybe protruding one millimeter.

The switch between the internal and the external audio paths is
controlled by software, so this shouldn't affect the internal paths
very much (only MICBIAS is shared, but it's protected by R4408,

Some of the test results from Taipei suggest that this won't help,
but given that not everyone seems to experience quite the same
symptoms, it might be worth a try.

- Werner

More information about the hardware mailing list