I got that infamous mbox noise problem. I have Mbox2 (not mini, not pro, just "2") and I can hear that white noise/hum every time i record with pro tools. I tried bypassing a mixer (Mackie 1402 VLZ3), tried connecting gear (MPC 1000) one by one and the same thing always happens. Although when I connected just the Motif XS tone generator i couldnt hear the hum at all. Then I realized it came with a 2-prong cord so its not grounded. All other gear is grounded and I get the noise whether they're on or off (im pretty sure it does not change that much when i turn instruments on, although it does get louder when i turn up the Gain knobs on the Mbox).

Okay so if it is a ground loop then how come I cannot hear that noise at all when the Mbox is off? I have no problems with any other gear, no extra noise or anything, they work perfectly well. I can only hear the noise when Pro Tools is on and the 1/4" cable(s) are plugged in. Its not just that I can hear it but it gets recorded as well. I normally use the DI inputs (TS unbalanced cables) but I also tried the Line in's - same result.

I have a PC (Windows XP Home, up to date; AMD Athlon 64 X2 3800+, Asus M2N-E motherboard, 2GB Ram memory). Yes I turned the other soundcard completely off, uninstalled the drivers and even re-installed Pro Tools (and Mbox drivers of course) using 2 different USB ports (No hubs; I even disconnected other USB devices). Also I have reinstalled Windows and I dont keep any unnecessary bull**** on the hard drive (Its really a Pro Tools based computer).

I've tried like everything to fix that, no luck. Do you still think its a ground loop? I cant hear it at all unless Pro Tools is running and my headphones are connected to the Mbox (or the mixer when the mbox's out's are connected to it). If it actually is a ground loop, then how can I fix that? Yes, I have read the Q & A on the Digi website but it does not help.

The electrical wiring is brand new and the building is brand new itself. Also, I took any unnecessary electrical devices out of the room and no, I do not have fluorescent lamps. Yes, I've tried different sockets for everything (mixer, Motif, MPC, computer, LCD monitor). What can I tell an electrician to do if it actually is a ground loop (or any other possible electrical-related problem).

I bought the Mbox back in August and haven't solved the problem since. damn