Received my MJ3 yesterday. I don't have a fancy FLIR thermal camera, just a cheap infrared gun. Mine topped out at 151 degrees after more than two hours of operation. The MJ3 was sitting directly on top of a Audio GD Master 9 with internal heatsinks that reach temps of 120 on its own. My rig is in my basement and the ambient Temps this time of year are around 70 degrees.