Comment 7 for bug 433573

I did it !

I've managed to make a configuration for echo3g devices.
When it is placed in /usr/share/alsa/cards/ PulseAudio will be able to automatically detect surround.
Not only that, but it will also be possible to switch between the following modes:
Stereo, Surround 5.1, 4.0, 4.1, 7.1 and even Digital Stereo Output. I have tested them and they all work!

So I'm attaching the config file: Echo_Echo3G.conf
It is necessary that it is named this way, otherwise it doesn't work.

Now I'm sure the configuration is far from perfect. I am certain it could be optimized a lot, but the important thing is that it works.
It would however be nice if someone could test it on other Echo3G devices, such as Layla 3G for example.