My old onboard sound (AC’97) was so crappy, that it didn’t even know the difference between silence and white noise. The onboard sound of my new notebook (Intel HDA (Realtek ALC262 chipset)) manages this quite well, but this time it doesn’t know the difference between music and white noise… To redeem the poor onboard chip, I replaced it by an Echo Indigo. Ugly, only two analog 1/8″ outputs but one hell of a soundcard! The best way to power a good headphone with a laptop.
Ok, back to topic.
Install “alsa-firmware”. Optionally “alsa-tools-gui”, if you want the original “echomixer” which could easily be replaced by kmix or similar in the everyday life. Restart alsa (Best way: Log out from your desktop env. Switch to console via Ctrl+Alt+F1. Log in as root. Then “init 1″ followed by “init 5″. Possibly switch back with Ctrl+Alt+F7.). Plug in the card. The blue LED should begin to gleam.
Now you are able to control the onboard sound and the Indigo via KMix (never tried Gnome).
Btw.: Took me several hours in my Gentoo days to achieve this due to a bug in the baselayout…
Amarok
I’m using the Indigo exclusively to listen to music. For the rest, the onboard sound is enough. Choose xine as the audio output module and select “Alsa” manually. Now replace “default” in the mono and stereo field with “hw:1,0″. That will divert the amarok sound to the Indigo. That’s the hack I used with gentoo. I’m sure there’s a more elegant, modern way. But hey, it works!
Marginally noted, in the good old days xmms could detect the second sound card automatically. The amarok developers are denying this fact strongly in their IRC channel. (“Blahh, that’s not possible! Never heard of it! Shut up!” etc. etc.) Perhaps, when I will have some spare time I will look after that feature (read: never… 
).
