I have an Onkyo 770 in an entertainment cabinet with a front tinted glass in wooden frame door. The back of the cabinet has a thin piece of plywood (thin enough to cut with a kitchen knife) in which I have cut out holes at the various shelf levels of the cabinet for the wires to go through. I have about four inches of space that I have left open on top of the 770 so that nothing is sitting directly on the top of the receiver. I have noticed that the 770 gets pretty warm, almost hot to the touch at times after being on for a while. Is this bad? Are receivers designed to work at these temperatures? Sort of new to this so if this is normal then a little reassurance would be nice If not then what have others done to help keep their receivers cool? Is it ok to leave the receiver on all the time?