Might not need to change the filter, but giving it a good cleaning might help. You might also want to check the hood/lid area--I've found that food sometimes falls into the lip of a tank, gets moist, and starts rotting--nasty, but doesn't impact the tank at all.
I'd also do a quick count, make sure all the fish are accounted for--jumpers usually don't smell, but you never know. Short term, running carbon will reduce the odor, but I think it's important to determine why there is an odor and address that issue as well.