Sound too low on tv/fm card
 

I've recently installed a TV/FM tuner (Philips 3139 147).

I connected an audio output plug to my motherboard's CD-IN audio connection (the one used to connect a cd/dvd rom drive).

I can hear sound but unfortunately it's too low. If I turn the volume up on my amplifier to hear the fm/tv sound well, all other sounds will be extremely loud.

I have all volumes maximized on both gnome-volume-manager and alsamixer.
I also can't see a "cd" volume control on either (or aux, for example).

I'm running Ubuntu 7.10 and, for that matter, my motherboard is a Gigabyte GA-P35C-DS3R.

Any help would be appreciated!