Troublesome Mbox

[Modest-Machine]

I've recently upgraded from a white Macbook to a new 21.5" iMac with Snow Leopard. I'm using an Mbox 2 with Pro Tools LE 8.0.4 with all the up to date drivers etc... My problem is I'm getting this horrible whine from my monitors (KRK RP6), and only my monitors - the headphone out is fine. I've been looking into ground loops and came to the conclusion that it is not one (I discovered this by plugging my Mbox back into my Macbook exactly as it was in my iMac and the whine went away). I've tried different leads, different power chords and moving everything around (and when not connected the monitors are silent as they should be). The only thing that I think it could be is a driver clash with Snow Leopard. I've emailed Digidesign, twice, and they still haven't got back to me. Any help out there?

[djgizmo]

Originally Posted by Modest-Machine

I've recently upgraded from a white Macbook to a new 21.5" iMac with Snow Leopard. I'm using an Mbox 2 with Pro Tools LE 8.0.4 with all the up to date drivers etc... My problem is I'm getting this horrible whine from my monitors (KRK RP6), and only my monitors - the headphone out is fine. I've been looking into ground loops and came to the conclusion that it is not one (I discovered this by plugging my Mbox back into my Macbook exactly as it was in my iMac and the whine went away). I've tried different leads, different power chords and moving everything around (and when not connected the monitors are silent as they should be). The only thing that I think it could be is a driver clash with Snow Leopard. I've emailed Digidesign, twice, and they still haven't got back to me. Any help out there?

Temp solution would to use a ground lifter on your iMac or monitor speakers. Also I believe the outputs on the mbox2 series is only TS not balanced TrS as I had the same issue.

It is a ground loop btw. Lifting the ground on your monitor speakers and or iMac will prove it.

[Modest-Machine]

Thanks for the reply. Sorry for my lack of knowledge on ground loops, haha - the outputs on the Mbox are unbalanced and so are my cables, however they are plugged into a balanced input on the monitors. Could it be as simple as switching to balanced cables?
Cheers.