Most products today are designed from the outside in, assigning aesthetics as the highest priority. Unfortunately, this often results in equipment that breaks down frequently and is difficult to troubleshoot and repair. No matter how good a piece of equipment looks, if it doesn't work, you can't use it. We accomplish this by using two separate chassis, one for the power supply and one for the amplifier. Furthermore, the output tubes are segregated to one side of the amp chassis which keeps much of the heat away from the components.
Ventilation is provided by natural convection.
If you place your hand on the back of the unit, you can actually feel air being drawn in through the rear. Most of the heat goes right out the top and doesn't bake the rest of the parts. This is evidenced by how quickly the unit cools down once it is shut off. None of this could happen if the enclosure was made smaller. One of the short comings of many tube amps is that they are made the same size as solid state amps.