Hello guys, I'm working on a studio and I noticed that the control room has a loud ground noise... even with all the faders down. Doing some tests I figured that the noise is coming more from the mix b section and the buses. If I have the main fader at unity gain and all the 8 buses faders at unity also, the noise is lower, if I move any of the faders higher or lower that unity, the noise gets louder... weird one huh? Any ideas? Could this be an internal problem? Thanx