Umm...unless you have power cables crossing all over your speaker cables this won't rule out a ground hum. You really need to unplug inputs into the 950 one at a time to figure out the where a ground hum would be coming from.

If the amp itself hums, I would think it would do it by itself with absolutely nothing connected either in or out of it. If this is the case, I would definitely be contacting Outlaw at this point.

One other little thing; I corrected a ground hum in my system with an in-line surge protector/ground lift on the the coaxial RF line. My local dealer gave it to me for free but I can't imagine it costing anymore than 10 bucks.