Tvad: Generally speaking, as long as gear is operated within its design parameters, it is not so much heat per se that damages or wears out electronic equipment, but thermal cycles experienced by gear getting hot and then going cold when turned on and off. That APL unit must be an extreme hot-rod design akin to a Class A power amp that passes large amounts of current at all times -- sounds like it needs heat sinking.
Many manufacturers will not advise in an owner's manual to leave gear powered up 24/7 due to liability concerns. Others address the issue by simply manufacturing gear with no on/off switch.
Many manufacturers will not advise in an owner's manual to leave gear powered up 24/7 due to liability concerns. Others address the issue by simply manufacturing gear with no on/off switch.