I use balanced XLR cables between my 990 and ATI 2005 (OEM's version of the Outlaw 7500) but there has been great debate whether (not to contradict FAUguy) there is an audible difference between balanced and unbalanced cables for the typically short runs between a pre/pro and the amp. I like the positive "snap" of the XLR connectors and the cost between cables was not that great so I went balanced. If I was trying to make a decision on an amp I'd be more concerned about getting the right amount of power (other posters have opined the 7125 is enough for your current speakers) versus whether the amp had balanced connections or not. However, if the amp is going to be some distance away from the pre/pro and you know you have a noisy electrical environment balanced cables/amp could be a benefit.

The design of the 7700 and 7500 are different than the 7125. Outlaw's Description, "The 7700/7500 differential design virtually eliminates cross talk, through a technology known as "common mode rejection". Compared to single-ended designs, the 7700/7500 requires half the rail voltage for a given power allowing for increased transient performance."

I replaced an Outlaw 770 amp (7 x 200w) with the Outlaw 7700 and there was more than a subtle change. I think the term transparency is the best I have heard. Even my wife agreed ,reluctantly, which has always been the "Mendoza Line" for me and audio purchases...

Cheers everyone!