A friend of mine basically inherited an Integra 5.1 receiver from one of his brothers. Good lord this thing is heavy. On the back it says that Integra is a division of Onkyo. It gives a model number DTR 5.1 Anyone know anything about this amp? Opinions? I found this link, and, this specific receiver is listed on the website under "previous models" http://www.integrahometheater.com/ What would something like this be worth now-a-days?