sa mga marantz owners. these babies do really get hot... hot, mind you, not warm. so my suggestion is get urself some muffin fan/s. they're not as noisy as some other ordinary fans. especially so if you have your gear in some confined space. they work wonders in keeping control of the air circulation. i got mine from deeco, the 220v type. got two of them on top of my sr4500. not too discernible both audibly or visually since it's between the 2"++ gap between the rack and the amp. your electric fan or aircon might be noisier if you have them on while watching video or listening to some music. to further reduce fan noise, try putting some spacers on the fan itself for some clearance between it and the amp. will post some pics when i have time.
btw, has any srxx00 owner tried using the speaker b output for biamping your fronts? since this is actually a pair of unused amp if u have just a 5.1 setup, then maybe we can put it to good use in powering up, say, the bass driver of a three-way front?!!? any comments?