Buzz on SA-5 headphone output

So, basically the mixer is working perfect to me, the main outputs are nice and clean but the headphone output is buzzing loud as HELL. That irritates me a lot when at night just mixing and listening records with only the turntables and the mixer on. Somethimes I'll have to put my headphones to the linemixer and listen through that cause I can't stand that electric buzz from my sa5 headphone out.
I have put the ground wires of TT's to the mixer, the main outs are clean but the headphone outs are buzzin. Should I ground the mixer to something or what?? Anyone else with the same problem?

No one? Is this maybe the wrong section to ask this question?

yes it is you want this
http://www.mpc-forums.com/viewforum.php?f=5