[astern]

Hello,

I too was having the high-pitched whine - only out of my monitors, not the headphone output on the mbox 2. after reading through this thread I decided to pick up a pair of TRS-XLR cables for my monitors, even though the guys at the music store said this would have no effect as the mbox didn't have balanced outputs.

This totally FIXED the problem. Completely. No more whine. If anyone experiencing this hasn't picked up a pair of balanced cables it's completely worth it.

Hope this helps,

Adam