It could fit on the bottom but I have my 5 channel amplifier in there. In addition, I have 6 and 8 year old children and I'm afraid they may hurt my tubes.
It does put out heat, but every tube amplifier does. I had a 50 watt deHavilland SET that put out twice as much heat, and a RAM Labs labs amplifier that put out about the same amount. I've also had VTL MB450's that put out a lot more heat, and the VTL tiny triodes that put out a little less. I guess its all relative, but the ARS puts out more heat than most solid state unless it is biased into class A.
troy