Whining from computer output into mixer

[Johnprogamez]

I connected my computer to the 3.5mm jack on my mixer and it  makes a obnoxious whining sound. I noticed that it does this whenever I uplug it. I have the wharfendale connect 802 mixing desk (non USB version) 

[The Flying Sloth]

1, Make sure the gain isn't all the way up, giving it too much volume can create a squealing sound, as can feedback between a microphone and speaker.

 

2, Try connecting over the RCA connectors instead of 3.5mm to avoid the possibility of bad cable

 

3, Failing that could you record the sound so we can hear it, different failures can have different sounds so it may help.

 

Sloth

[Johnprogamez]

Changing to rca did help a bit but i still get a faint whining noise still

17 hours ago, The Flying Sloth said:

1, Make sure the gain isn't all the way up, giving it too much volume can create a squealing sound, as can feedback between a microphone and speaker.

 

2, Try connecting over the RCA connectors instead of 3.5mm to avoid the possibility of bad cable

 

3, Failing that could you record the sound so we can hear it, different failures can have different sounds so it may help.

 

Sloth

 

sound.mp3

[The Flying Sloth]

Yeah, that sounds like EMF to me (interference), do you hear sound like that when using speakers on the computer or not? because if the interference isn't coming from the PC it's either being picked up by the RCA cables or the power pack on the mixer, if the sound is present without anything plugged into the mixer it's bad power and it it's only when plugged into the PC it's either from the PC or cables. Unfortunately you can't used balanced connections to help shield since you're taking analogue out of the PC but shielded cables may work if the interference isn't coming from the PC or power pack, if it is coming from the power pack I'm not too sure what could be done to fix it, it's a cheap mixer without a solid name behind it without digital connectivity options. 

[anothertom]

Definitely sounds like EMI. You can try to alleviate the issue by separating audio cables from any others as much as possible, both internal and external. A USb DAC can help prevent this by removing the conversion outside the case but other cables can still have effect.