I get this annoying buzzing on my recordings as demonstrated here. When I turn down the highs, it's much less noticeable during actual sound but is still present, plus I'm bringing down a lot of the brilliance of my instruments.

I was using on-board sound (ASUS A8N-SLI mobo) but then popped in an old Creative Audigy 1 card and was dissappointed when I got the exact same result.
I am using Adobe Audition to record but I have also tried Audacity and Windows Sound Recorder and the problem exists there too. Also I have tried some simple Linux recording prog.

I have looked at some cards and am considering the M-Audio 2496 but don't want to spend money and have the same problem occur because it's a software problem, so if there's any possible solutions out there, I would greatly appreciate it.

The buzz is not in the FLAC file. Could you possibly have blown a speaker??? Nice playing, by the way.

Cheers.

I think the "buzzing" he's referring to is the constant noise background, which I'd describe as a "zizzing" (if you'll excuse the made-up word).

That noise sounds to me like something is picking up some interference. Perhaps a dodgy cable with a bad screen? Try a different cable between the piano/mixer and the PC. Another thing to consider is the monitor. Try turning it off while you record to see if that makes a difference.

Also, your recording levels are very low (peaking around -16dB), so any interference that is present will seem much greater in comparison to the signal. Try to boost the signal level from the piano/mixer before it gets to the soundcard.

Best bet is to try with a friend's PC and see if the problem persists.

It is a hardware problem. You haven't said what your premaps are because they could be causing the problem. Assuming your source isn't line level that is. With a decent soundcard if there is a problem it will be before the sound card. If you want decent recordings you need a proper soundcard anyway. Tell us more details about your set up and we can probably say what's causing the buzzing.