Cool it!

@tomavodka:
It’s very normal for Krell amps and most class A biased amps to become very warm-some even hot to the touch.  Be sure not to impede the air flow around them,  thus no stacking other components on top, or placing them inside cabinets etc.  Common sense stuff.  Remember-a class A biased amp is always “wide open” when turned on.  I have stated this comparison many times.  They’re like a hot fuel dragster sitting at the line waiting for the the green light.
Steve

At full Blast, my amps run slightly warm.  I attribute it to the huge power supplies that allow the outputs to coast as they alow the electricity through, rather than working hard to extract it from a small power supply.  The amps use very little bias, because it is not necessary, and causes heat to be produced.   Since the amps a in the next room, I did use a small fan on a Bryston for a while.  One interesting design for an amp is the Audire Monarch.  It is a tower lined with many output transistors, and has an open bottom to let air rise for cooling out the highly vented top. The design reminds me of the old GE tube amp my family's movie theater used in the 1950's, but could have been even older..  It was 100 watts, about 5 inches thick, at least a foot and a half wide, and about two feet tall. All visible surfaces were totally perforated.  Some audiophiles like to open the tops of their amps.  This did help my Bryston run cooler.

I have always preferred Class A amps with properly designed heat sinks that cool sufficiently without and added fans (which might fail, possibly cooking your amp).

I have one system that runs two mono Class A amp, each of which puts out around 400 watts in heat just sitting idling (they actually put out less heat when working hard as some of the current is used in outputting sound).  They run hot as Hell but were intended to run that way, and have been for more than 30 years

The problem with this sort of heat sinking is that it tends to be pretty large physically. The ones I use are 16.5" high and weight more than 100 lbs. each.  I would get nervous with any amp that would turn to trash if a fan motor failed and you didn't notice immediately.

HOT air rises so always have ventilation on top of unit.No need for a fan.

"Hot air rises" goes to show why Geoff has the highest post count...