Help! Is my new McIntosh MA12000 broken?

Hi, can you please help me?

I bought my first McIntosh amp, MA12000 and it is making a pretty loud hum.

It does not come from the loudspeakers.

The hum comes from the amp itself. 

With or without any sources connected to the amp make no difference to the hum.

I`m a bit surprised that such an expensive amp is so noisy. 

Do you think there is something wrong with the amp or is it supposed to make that humming noise?

Any and all answers are very much appreciated.