Edit: Clarified this question to point out the differences between this and the one marked as a duplicate

I have a Blue Snowball USB microphone plugged into an HP PC running Windows 7. Whenever I record, the mic pics up what sounds like an electrical noise. The pattern sounds almost like morse code. As I lower the recording levels, the noise goes down as well. Here's a link to a sample:


After some research I found some other examples of the same noise and it seems to be emanating from the PC's power supply.

Here's what I've tried so far to eliminate the noise:

-Turning off every piece of equipment (including battery-operated devices) except the PC and monitor

-Moving the microphone away from the PC

-Removing ground on everything plugged into the PC and leaving the PC grounded

-Removing ground on everything including the PC

-Using a powered USB hub between the PC and the mic

One of the answers to this question suggests using a professional sound card. In my case, I'm using a USB mic, not a mixing board, but the answer got me thinking about installing a USB card with some sort of isolation from the interference. But I don't even know if these exist.

What other steps can I try, short of using a different PC or power supply, to get rid of the whine?

Answer: The microphone turned out to be defective. A new microphone resolved the mysterious sound. I am not able to answer this normally or accept and answer because the question is still incorrectly marked as a duplicate.

  • Morse code?... my guess... Mobile Phone.
    – Tetsujin
    Aug 28, 2014 at 20:03