Need Help! My Class A Amp Is Running Very Hot

Have you talked to your dealer? What did he say?

Although others hear are diagnosing your amplifier with positive, absolute, definitive assessment they cannot know what might/could be wrong with your amplifier without a firsthand inspection or more information than you have provided it may well be functioning completely, fully, and entirely within the manufacturer's intended operating parameters at the very least/minimum you need to measure the temperature of the unit itself.

Actual temperature? "Burning hot", is very subjective! No one can(possibly/correctly) answer your question, without that fact/measurement. Not even the manufacturer. btw: your amp has a protection circuit, that will turn it off, if it senses over-current, abnormally high temperature, or DC drift(per the first page of the Owner's Manual).

The L-590AX is spec’d as consuming 220 watts at idle (310 watts max). The L-590AXII is spec’d as consuming 260 watts at idle (330 watts max). Both models weigh about 63 pounds. The amp’s heatsinks are entirely enclosed within its metal cabinet, and are immediately adjacent to the side-panels, as can be seen here: 

http://www.luxman.com/asset/product/L-590AXII/gb4.jpg 

So the escape route for the heat corresponding to those power consumption numbers is almost entirely via the vents on the top, supplemented to a small extent by radiation through the side panels.

Given all of that it seems to me to be very possible that what you have described is normal, but it’s hard to say for sure. Perhaps another owner of one of these models will chime in.

@three_easy_payments, I believe the OP’s reference to "cabinet" pertained to the metal enclosure of the amp itself.

Regards,
-- Al

Hi there, the cabinet on the top temperature is 28C which I think is just a little warm but acceptable but when I put my hand on top of the plastic vents (over the heat shrinks) it is extremely hot, way over my thermometer maximum temperature of 50C