A few suggestions. If you haven't already, replace your outlet with a good quality one. Look for a P&S with brass construction or unplated Hubbell. If you're using a nickel plated or silver outlet, your problem could be there. Next, plug the amp directly into the wall.
Experiment with the room. Try moving the spkrs. around & maybe in dramatic fashion, like way out into the room. They don't have to stay there but at least you'll get an idea of what's going on. Just a little toe in makes a big difference too. Search the archives for testing your room for liveliness & make as many adjustments as necessary.
There are a lot more little things you can do but these few things should give you an indication if there's a problem somewhere else.
Moving on to IC's, my recommendation: Magnet Wire cables. Check out the info under A-gon member Motoman.
You can pick up the outlet & the magwire IC for well under $100.00. Good luck taming your system.
Experiment with the room. Try moving the spkrs. around & maybe in dramatic fashion, like way out into the room. They don't have to stay there but at least you'll get an idea of what's going on. Just a little toe in makes a big difference too. Search the archives for testing your room for liveliness & make as many adjustments as necessary.
There are a lot more little things you can do but these few things should give you an indication if there's a problem somewhere else.
Moving on to IC's, my recommendation: Magnet Wire cables. Check out the info under A-gon member Motoman.
You can pick up the outlet & the magwire IC for well under $100.00. Good luck taming your system.