Slight hum in my amp. Is this normal?

have experience with this one.  DC is in your line.  It not only can cause hum from the transformer, it can damage it (AND WARRANTY will not cover it) if you use it like this over time.  Bought a DC filter from EMOTIVA,  around $100 as I recall.  works like a champ!!!
SILENCE.   My humble opinion.  a great product for the money

 I was having the same problem a little while ago where my amp started humming. I tried multiple things without success but later I found that the problem was being caused by a potable heater connected somewhere else in the house.

if you ground is not isolated everything that is connected to the house is picked up by some of your components.

in my case that's all it took to get it fixed.

Hope this helps.

Adalberto

I have a modwright integrated KWI-200 that developed a hum that got louder over time. I finally had to send it to them and they replaced the transformer.
if this is a new problem since you moved, I don't believe in coincidences. 

I explained again that it was loudest when you first power it up then the hum diminishes after a few seconds but is still audible. He wants to keep power applied to it and observe.
Another thing I just remembered and haven't mentioned, since the hum began, it has been running a bit warm even at low listening levels when it was in my system.

Its 100% normal for any toroid to make a bit of noise on startup. This is because the core of the transformer can become magnetized when the unit is turned off. The next time its turned on, the magnetic field causes saturation in the core and the transformer rattles until the magnetic field is degaussed by the alternating current.

The second paragraph above suggests that the bias of the amplifier is high- which could account for the additional mechanical noise.

Picked up my amp today and at the shop it seemed dead quiet however, there's ambient noise in the shop. According to the owner, early in the morning he heard nothing. It was dead quiet. After getting it home I spent the evening re configuring all my wiring taking care no power came in contact with any signal wire. here are my results as I emailed the shop owner:

Hello Morris,
It’s about 10:20 pm and everything sounds great however….
Remember I said that the “hum” could be heard from 10 ft away? Well I just unplugged and powered everything off one thing at a time and here’s my findings; What I can hear from 10 ft away is coming from the speakers. Yes there is a very slight “hum” in the amp and it’s also coming from the speakers. If I disconnected the interconnects from the preamp, no change. Of course since the power is off on the preamp and no signal feeding to the amp. Then I disconnected all the speaker cables and yes there is a “hum” or “buzz” in the amp. It has to be very quiet in the room to hear it.
This “hum” or “buzz” is not only in the amp but sending it through to all 5 channels. this explains why I can hear it from my listening position. I have a surround sound “hum” or “buzz”. So yes, the “hum” or “buzz” is in the amp and the amp also sends this noise to the speakers, all 5 channels. Could it be a bad ground causing this? Again if its the ONLY component with power connected, how could that be? Btw, there is no other electrical device on in the house other than an incandescent lamp for light. I tried powering it straight from the wall, using the Torus TOT MAX, and straight from the wall with a Emotiva CMX-2 Precision AC Line Restoration and Common Mode Filter System without the Torus.
I can only suspect it’s a component in the amp that is defective common to all 5 channels.

Any ideas anyone?
As a last resort, I will send it to Anthem in Canada. Being a current item, they will have all the components to trouble shoot with. It's just expensive to ship from California to Ontario, Canada. May be my last and only option.