vetsdiggy wrote:Yes the niose came as soon as I put just one output to the desk via the PB..
Oh err... That stirs up the waters a bit... Something weird going on with your patchbay then...
Can I presume that the patchbay metal work isn't touching (or in any other way connected to ) the Apogee or mixer metalwork ?
However this did lead me to think it could be a ballance issue?
Are you sure that the patch bay is balanced, and that all your cables are balanced and wired correctly?
This is reinforced by the fact that now when I try a mono signal sent unpanned out from Logic down a stereo output (so equal signal each chan), but run one direct to the desk and one through the PB (no DI in any chain), I notice that not only do I have hiss on just the chan run via the OB, but I also have a significant drop in signal level?
If the level drop is 6dB that would suggest that only one side of the balanced signal is getting through.
Are you using TRS cables to connect the equipment to the and from the patch bay... and using TRS cables to make the patches? Sounds like you might have some unbalanced TS cables in there somewhere (or the patchbay is an unbalanced patchbay!)