I have B&W Nautilus series as my HT that includes 804s as front, 805s as rear, HTM-1 center and ASW-800 sub. Currently, I am using Marantz Receiver SR7300 to drives these but my dealer told me that I should look at upgrading receiver or adding an amplifier to get better results. Any ideas which amp will be better for this setup ? My budget is around $1500 but can stretch to $2000. Thanks for taking time to read my post and your replies.