I have made two graphs of the hums frequency content (via some Matlab wizardry). The "zoomedout.jpg" shows most of the frequencies in the signal. The "zoomedin.jpg" shows that 60 Hz is by far the loudest frequency. Interpret as you please.
<br><br><a href="http://www.prism.gatech.edu/~gtg601q/LAU/zoomedout.jpg">http://www.prism.gatech.edu/~gtg601q/LAU/zoomedout.jpg</a><br><a href="http://www.prism.gatech.edu/~gtg601q/LAU/zoomedin.jpg">http://www.prism.gatech.edu/~gtg601q/LAU/zoomedin.jpg
</a><br><br>-DanielG<br><br><div><span class="gmail_quote">On 7/30/07, <b class="gmail_sendername"><a href="mailto:linux-audio-user-request@lists.linuxaudio.org">linux-audio-user-request@lists.linuxaudio.org</a></b> <<a href="mailto:linux-audio-user-request@lists.linuxaudio.org">
linux-audio-user-request@lists.linuxaudio.org</a>> wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><br>------------------------------
<br><br><br>I have been told that this is probably caused by the power distribution circuitry within the laptop: it does not separate earth ground from "signal" (I'm assuming USB signal since my audio interface is USB) ground. The buzz certainly sounds more like "computer" noise than 60 cycle hum.
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