Humming problem!

I got my MPC60 connected to a little studio mixer with the 8 assignable out's to EQ the individual sounds from my MPC.
The studio mixer is then connectred to a regular scratch -Vestax- mixer (through Line In) and from that mixer to amp.

When I turn the master volume of the scratch mixer all the way up there is a humming noise comming out of my speakers,
when I switch from there over to ''Phono In'' you only hear the ''his'' of my turntable but thats normal.

I'm not quite happy wit the humming noise though comming from my MPC through the ''Line In''.

I got the 8 outputs of my MPC connected to the studio mixer with 3ft mono unbalanced instrument cables, and from there I got the ''monitor out'' of the studio mixer connected to my scratch mixer with a 6ft White & Red stereo cable but also unbalanced.


I think it has something to do with the cables being unbalanced but I don't know for sure.
can somebody help me out

thanks...

does your Vestax mixer have a Ground pin on the back? some mixers which have an external DC power adaptor need grounding by connecting that pin to a ground pin on the amp

^^ what he said and also, make sure you using balanced audio cables ...and try keeping your audio cables away from electrical to avoid interference

On the joke side of things........it could be that ole barbershop quartet that's responsible for this, or farmer Brown has a stench problem because of all the hogs he's got.