strange sound at 1250Hz

can anyone help me with this?
what is this strange sound at 1250Hz coming out of my speakers? does it have something to do with my disk drives? is seems to occur when there is activity on the hard disk. but not always. so, i am not sure.
anyone heard it before? anyone knows what it is? anyone knows how i can get rid of it?


here is a recording of the sound:

Some kind of electrical interference, for sure. I can hear a similar sound from my laptop’s cheap audio card while listening to stuff on headphones. Heavy HDD activity can result in some noise, and also, rather more bizarrely, graphical activity. If there are objects on screen with highly contrasting edges it will produce noise, or moving windows around the screen will cause noise, and so on.

Generally speaking, some component in your system isn’t properly electrically shielded.

Yeh I have heard weird crap like this on older computers of mine back in the day. What kind of soundcard/audio interface are you using?

Does it happen when the disc drive spins too?

First thing I would check is if the “CD Audio” cable is connected between the optical drive and the soundcard… And if so, disconnect that thing… <---- This exact solution fixed my similar problem long ago.

Alternately, try other soundcards in the computer, or get an inexpensive USB audio interface which will be less susceptible to interference.