Cool concept, but the recording itself needs some work.  I think your gain was too high when you recorded it, because there's a lot of clipping, which causes the sound to distort.  (You can see this if you look at the preview image for the sound -- note how a large portion of it is solid white.  When that happens, it generally means a loss of sound quality.)

Bart only wanted to be constructive.
I like the riff but I have to admit that in my case the "dirty" sound was not that well recieved in my ears. (I was wearing headphones.)
Nevertheless you are right, there are soundtracks which also use such grungy effects.

This is clipping badly, though.

For your next recordings, keep in mind that dirty grungy distortion (or distortion of any kind) is achieved properly by effect processors (either hardware or digital plugins), which produce harmonic distortion by doing dynamics processing of the signal, just like guitar amps/pedals do. And make sure not to let your audio exports clip (for basics, you could just look at the amplitude meter and make sure it never goes red :D)

Regardless of the OS, built in cards just won't cut it for recording.

There are several USB interface makers, they all praise their low noise hardware, so you'd have to hear yourself to judge, but even the crappiest one should fare a lot better than a built in card. Budget permitting, getting something that works at least at 96kHz/24bit should be worth the extra bucks, higher quality pays back when you do a lot of post processing.

What you can try right now is some noise removal by software. Audacity can do noise removal, but since you're mentioning Linux you can try Gnome Wave Cleaner; I've been provided very noisy vocals lately, and GWC did a good job on them.

I'm not sure.  Are you coming here through a proxy, or from an ISP known to be spam friendly?   Every once in a while, the spam filter flags something that doesn't make any sense. Anyway, I'll make sure it doesn't bother you again. Sorry about that.

I have no direct experience with such kind of hardware, here's why listening with your ears would be the most reliable thing. Considering that even comments/reviews on the net sometimes are fake, if I had to buy such an interface I guess I'd check the most reliable audio production forums.

What I can tell you is that the USB mic I've used to record my own vocals is reasonably quiet; I still do noise removal on the recordings, but the result sounds good for a non-professional device. I'd expect any interface from at least the better known brands to be on par with my mic. By the way, although Linux is not mentioned at all on the specs of my mic, it works flawlessly like an extra audio card (which it actually is); its settings are all available in the ALSA mixer and Audacity can record from it.

As long as the interface is true to the standards, it should work with Linux even if not specified.

Oh, if you haven't yet, have fun with Guitarix and Rakarrack !

MikeeUSA: Hey, thanks.

I haven't tried to make audio hardware work on Linux in years, and back when I did, it was nightmare. AFAIK most mainstream audio hardware manufacturers have a bad history with regards Linux support (MOTU comes to mind). But there's plenty of people making good recordings and mixes on Linux, so ask over at http://linuxmusicians.com for some guidance.

Regarding noise, copyc4t is right that any decent audio interface will have a decently low noise level.

With a USB interface, the only actual sound transference is from your instrument (and perhaps an effect pedal, etc) into the interface. After that, it's all digital data. So, for an interface to add unacceptable noise to a signal (where you're sure the noise isn't coming from your bass or whatever you have plugged into the interface input) would be an extremely rare thing. Something I'd expect only from a really bad quality piece of hardware, or maybe a mismatch in input voltages, bad cable somewhere in the input, etc.

Also, since you're both looking to make crunchy/distorted sounds and are concerned about noise, keep in mind that any ground/static/room/etc noise that does get into your interface during recording will then likely be amplified by your fx processing. So, make sure cables are good, inputs and outputs match, instrument's electronics are good, and no air currents (from air conditioner, room fans, open windows, etc) hit your guitar/bass pickups or vocal mics, because acceptable background noise can become unacceptable (too high) after amplifying things with a distortion gain or whatever.

Finally, with regards to both noise and the 24-bit thing copyc4t mentioned: Even though 24-bit is desirable for lots of processing like copyc4t said, a 24-bit recording is not really desirable if you're in a noisey setting. Recording to 24-bit in a noisey room will just catch more noise. If a dynamic range of 96dB (what 16 bit recordings have theoretically) between high and low is already yielding you background noise problems, then adding 8 bits of dynamic range down (which is what 24-bit does) will only grab more noise from your mic. In any case, this is a longer discussion that's probably overkill for what you're trying to do! :D. But at least you now have some terms and concepts to google. BTW I recommend http://www.gearslutz.com/board/ for hot debates on all these topics.