I too have the Denon 3300, but haven't had the fan problem. It needs LOTS of air since it does run hot. Since the unit is installed in my audio cabinet, I have provided 4" of space on top of the unit, and always keep the glass doors open.
Denon AVR3300 fan = too noisy...help?
I have a Denon AVR 3300 receiver, the performance of which I am quite happy with, overall. However, every minute or so, the fan kicks in, which produces a rather loud, almost whining noise, which is very audible in quiet passages. Has anyone else had this experience? Are there aftermarket fans out there that can be used as a quieter replacement? Any other ideas or tips? Thanks.