I agree in principle with some of the points made by Jfech.
The 300IX is a very fine integrated and deserves proper care and feeding.
I have found a couple of key accessories from Walker Audio can really do what you are looking for.
I recommend to my customers that they use a set of Walker HDL links which are noise filters which connect to the back of the speakers underneath your speaker cable.
The HDLs really open up a system's sound and improve focus and resolution.
I also recommend the Walker Valid points which are very effective and inexpensive vibration control.
The Valid points are brass and lead damping discs and cones.
When used correctly they also increase the air and sound stage.
There are many great power cords to try.