I have a 5 1/2 year old Sony STR-DA80ES receiver that recently broke down. The problem is the front left and center chanels are very low volume and garbled. It is NOT in the power amp section as I checked it at the pre-outs. The estimate to fix it ($200) but haven't gotten the explanation of what exactly is wrong. My question is: should I go ahead and fix this older unit or buy an upgrade? My budget for an upgrade would be under $500. I've been looking at the closeouts on the HK AVR325. Thanks ps. I do not use the main amps on the Sony as I've got an Adcom GFA-545 power amp for the main speakers (FL & FR).