Noisy Soundcard

I have noticed that my sound card output is quite noisy, before when I had my monitors plugged directly into I assumed it was the sensitivity of the monitors and so I set this really low so the noise wasn't noticeable.

Now I have bought a small mixer the sound is now apparent on the channel strip I run the card into.

Its a fire wire fa-66 but I am using the small firewire plug into the built in firewire port on my laptop, which I guess is for digital cameras.

Is that the reason the noise is happening? I was only using this input because a pci express firewire card is so expensive and my laptop has no pcmcia slots on it.