How can I get line-in microphone working with Skype?

I got it working by doing this. You should enter the commands in a terminal.

1. Install pulseaudio if you haven't done that already:

   sudo apt-get install pulseaudio
   

   or using Software center

2. Install pavucontrol and pavumeter if you haven't done that already:

   sudo apt-get install pavucontrol pavumeter
   

3. Restart to get pulseaudio running

4. Start pavucontrol, and make sure that input/output is set to Audio Stereo Duplex
5. Start alsamixer, and set the values as follows:

Output

- Master: 100
- Set the others values on 63, including CAPTURE

Input

- Line-in: 40
- Mic: 63
- Phone: 40
- Aux: 40
- Analog Source: mic
- Digital Source: i2s in
- Shared Mic: mic in

If you get a strange 'looping beep' right now, don't worry, this happened to me too.

Start Skype.

Because of the restart you did earlier, Skype should automatically use PulseAudio. Make sure that you don't allow Skype to change the volume settings. You can do that in Skype's volume settings.

Make a test call to confirm that the microphone works.