Inspite of the good advice and facts John brought up, I would be willing to say that you may in fact find better sound quality with a new avr, ie. Denon, Harmon Kardon, Yamaha, Onkyo, etc., just might yield better amplification, especially if you are looking at playing the M60s at louder volumes, say 85db and up. I had a Sony similar to yours, it was older bought in late 2003 and compared it to a Denon and running my M22s, the Denon had a better, more authoritative bass, it just sounded batter to me. I know others have found similar results. You could always buy one, compare it and if it doesn't sound any better, take it back.
