Okay, I bought a JVC KD-HDR1 car stereo unit with HD radio. Among other things, it lets me listen to BBC off the air anytime I like (compliments of a local NPR affiliate's digital sub-channels). After hooking it up for a while at home, I thought I would install it on my boat. The sound quality improvement of FM stations is noticeable.

This unit is now available for $200 which I think is a steal. The one thing that concerned me was that the JVC runs *incredibly* hot. You could fry an egg on it. Other buyers of this unit have noted that.

The incredible heat of the JVC made me wonder if it might be gulping amps; this is a particular concern on a sailboat. I don't really want to run the engine to charge batteries to keep the stereo going.

So I got my multimeter and did a comparison of the existing modest Kenwood receiver and the JVC. With both of them warmed up and volume set low, the Kenwood showed 4.0A draw while the JVC was pulling just 0.8A!

I know there are a lot of other variables here that I might try to solve for, but I am just puzzled. The JVC seems to sound fine when I crank it up, so it is putting out *some* energy that isn't heat, but it just seems like it would have to pull more amperage to heat the case up to such a remarkable degree. What basic principle of solid state electronics am I overlooking?

(If I decide that I am happy with the JVC I may buy another for the car for my "phase 2" Empeg reinstall with the display extender.)