I am brand new to this forum! I just bought a pair of Polk Rti4 speakers today. I am currently running them off of an old Philips stereo receiver (7831). When I turn the volume up it crackles, and past 2, it crackles real bad. I was considering getting this fixed, but I don't know how much it will cost, does anyone have any idea what is wrong with it? I will probably be better off with a new receiver. I have been looking some at stereo receivers, Onkyo 8511 vs Yamaha RX-596, what do you guys think?