Laptop noise through mixer?

[mr-s]

Anybody got any ideas why, when i connect my laptop to my Numark mixer, with the laptops PSU attached, i get this ridiculous humming noise coming from the speakers?
It seems to get worse when its loading, or im moving the touchpad?

Thanks,
Scott.

[Quinnx.]

Its all down to a thing called
Ground Loop

You need to use power filters and balanced cables.

[howardS]

Quinnx, I have the same issue on my Fantom X6. I get a noise when I play my laptop through the audio inputs but I don't think that the Fantom has balanced inputs. It also doesn't happen when I play an MP3 player through the same wire, only when the music is coming out of the Laptop.

Interestingly there is hum when I play the laptop through my stereo so I guess the ground loop is only happening between my laptop and my Fantom. Any suggestions to reduce this hum?

[Quinnx.]

That would be true..
especial since i am assuming the mp3 is not on A/C
but runing on battery..,

Im not responsible for what you no next..

http://www.google.co.uk/search?hl=en&q= ... +hum&meta=

[howardS]

Thanks, Quinnx. I will play around with this a little. I consider myself warned.

[mr-s]

Thanks.

Ive looked into it, and ive purchased a 'Ground Loop filter' from Maplins.
That should do the trick!

Scott.

[mr-s]

I received my 'Ground Loop filter' today, and its worked a treat!

Only problem now is that, when my MC808 is hooked up to the laptop, the ground loop follows through the laptops USB to the 808, then back to the mixer, which brings the humming back!

Looks like i'll be buying another one then!

Scott.