Noise on mixer (urgent)

[Chviet]

Hey, guys so I'm using the Yamaha MW 12Cx . When I used it for recording before, it didn't have noise. Now that I'm using it again it produces noises. I've tried different instruments. I have a E.G guitar and it works fine, but it has this gain like noise same goes with the microphone. I don't know when it started it just did. Does anyone know what might be the cause of it?

 

[Seidy]

Are you using compression? Maybe that pumps up noise.
Are the effect section turned on? Effect units could be noisy.
Another cause might be inproper gain staging.

Are you sure that noise comes from mixer? I mean maybe your speakers or some other link in your setup produces noise.

 

[GuitarLegend]

I had a similar problem a while back that turned out to be the routing of audio cables to the mixer in close proximity to power cables. When I separated them, the noise was greatly reduced. A little more work without cable routing seemed to get rid of the problem. Like yours, it turned up suddenly or so I thought but it probably followed a rearrangement of gear and an attempt to tidy up the cabling.

You could disconnect everything and reconnect one at a time to try to determine what is causing the noise. If the mixer produces noise without anything connected, a remote possibility is simply an electronic breakdown but equipment is pretty good these days. I would be looking at where your cables lie.

Balanced cables offer some noise immunity but proximity to something noisy doesn't help much