Why does my reciever get hot?

Hey folks

I used to have a technics reciever with RCA-style briding clips (only reciever i have ever seen like that, you could even plug a pre-amp into the opposing input from where the pre-hit the bridging clip and use a seperate processor with the internal amps on that reciever. not that you would, it is just weird that you could) that i could remove and plug amps into and turn the thing into a pre-amp. It ran cool that way, which makes sence cause the amps are not on.

Now i have a Denon 3805. It has PRE-OUTS, and for the front 2 channels im using an external amplifier.

Now, seeing as how the speakers are plugged into the amplifier and not the reciever, when listening to STEREO or DIRECT modes the reciever still gets hot to the touch.

I had assumed that the dumb thing would run cool if there was a dead OPEN between the speaker terminals, cause the CKT is no longer complete.

Anyone know why this thing still runs so warm? It is not any cooler than when i had the speakers hooked up to the terminals on the reciever. I was just wondering if this is NORMAL.....