Since this is a vintage amp, Japan made between 1987-1989. I'm assuming it runs so warm, even when not in use, is A; very high current and B; it's class A/B circuitry.

Does anyone have any info regarding it's power supply? Does it have toroidal transformer? What the heck is powering this thing causing it to stay so warm all the time?

Thanks.

Great amp for power. I use one bridged to power my subwoofer. I believe it is technically a class g amp since it will adjust voltage depending on current needs. Mine runs warm to the touch, but nothing I would call excessive.

Yeah, it's not hot, but definately the warmest piece of equipment I've ever owned. I'm going to cusomtize some ventilation holes so it will hopefully dissapate a lot of that heat and help the amp last longer.

You're right, the specs on this thing indicate that at 8 ohms it will turn out 400 watts, 4 ohms 600 watts and 2 ohm 800! My only concern is something failing and the repair shop not being able to find a part, or it will cost more than the amps worth. But as of now, it's really making the 603's play VERY well.