[kheldar]

I have seen a few of them now, based on different amps and sound cards. Almost all of them have a huge peak at 1000hz and what I assume are harmonics of that frequency going up, is this normal for computers? or is it something to do with the software?

 

[tangent]

You're seeing the 1 kHz test signal. It has to be there. Without it, you just have a noise test.