meter lights getting dim on your carver do not indicate clipping, if you dont have enough power to run the meter lights at full then your amp is starving for juice.
your amp should be pluged directly into your wall outlet & without the 50 ft extension cord either, amps suck an awfull lot of current & in most cases the shorter the run the better.
if you have an unused circuit why not just move the outlet from the closet to a better location & just use it for your system.
shouldnt cost more than a hundred bucks.
mike.