Last summer i made the investment in a full 5 speaker surround system and have been enjoying it since. It is composed of Athena AS-F2 fronts, Athena AS-C1 center, and AS-B1 surrounds. I am running them with a Panny xr-55 which at the time was getting rave reviews. Besides getting a sub, this summer i would like to upgrade receivers, something more warm sounding. DUe to living in a small town I have no way of auditioning receivers. Please let me know what may be the best receiver for this system, something warm and under $500. Ill research any models suggested, thanks a bunch everyone.