OK, I have a Marantz SR5400 Home Theatre Receiver which I got from the late Andy Fletcher's estate (RIP Mate).

Works very nicely now I've downloaded the manual and actually read it

BUT

It runs very hot, hotter than I would have anticpated (so warm I'm thinking of installing a fan), obviously I can't ask Andy if that is correct, so does anyone else have this receiver, does yours run hot?

It is in a TV unit but there's plenty of free space all around so I don't believe ventilation is the issue here.

And no, I'm not running it at disco volume levels, my hearing is buggered enough as it is

I have a Marantz, I think the 5600. These types of amps are naturally hot all the time they're on, whether you're using them or not. It's just natural operation. Leave a couple of inches of clearance around the amp, and it will work fine. Mine has worked without a hitch for years even though it's been pretty hot. You might want to turn it off if you're not going to use it to save power.

I have the SR7300 and it runs quite hot whenever it's on.

I personally have a 5600 and yes it does run hot, as do most home cinema amplifiers. Although you should still be able to touch it, i.e not frying pan hot.

Cheers guys, I figured it probably has Class-A output stages (or something pretty close), you pay for the low distortion with heavy idle power dissipation.

As an engineer it just goes against the grain to have such a high power device without forced ventilation. My old Quad 405 Current Dumper ran almost cold, stupendous performance for it's time, sadly lost in my divorce

I may still fit a low noise fan, can't hurt the reliabilty.

I also thought that it might be a problem, since I have it in a room where I hardly ever turn on the AC. It's got around 1.5 inches of clearance on the top and is open on the sides. It get warm-hot, even when it's not used but on, but it's never had a mishap. Most AV receivers operate this way and get similarly hot.

The one problem with this may be that it's using a lot of electricity even when you're not using it. That's why I say you might want to turn it off when you're not using it.

I also thought that it might be a problem, since I have it in a room where I hardly ever turn on the AC. It's got around 1.5 inches of clearance on the top and is open on the sides. It get warm-hot, even when it's not used but on, but it's never had a mishap. Most AV receivers operate this way and get similarly hot.

The one problem with this may be that it's using a lot of electricity even when you're not using it. That's why I say you might want to turn it off when you're not using it.

It's definately getting turned off when not in use

The manual is a dead giveaway, it says you need EIGHT INCHES all around the unit for proper cooling, like you I've got a couple of inches all around.