Slight hum in my amp. Is this normal?

Thank you everyone for the great intell. I bought a Torus TOT MAX yesterday at a killer price and the dreaded hum is still there. I'm convinced its internal in the amp and something isn't right. This morning real early I powered it up with no input. Nothing else was on and I could hear a ver faint hum from 10 ft away.
I've sent an email to the local Anthem authorized service center, who told me this is normal, and we'll see what they say. As I mentioned before, there has never been a detectable noise (hum) from this unit until they disassembled and re assembled it. Worst case, I bite the bullet and ship it to Anthem factory at a hefty shipping cost.

I once had a subwoofer that had an internal hum.  It was actually more of a very faint buzz, but audible when it was quiet.  The manufacturer of the sub acknowledged that some of their transformers were noisier than others and they sent me some parts to install around the transformer that physically isolated it from the cabinet and the noise went away.  If in your case the service involved "disassembled and reseated everything" then I suppose it's possible that what you are hearing is resonance from vibration.  They would need to loosen and retighten the fasteners holding the transformer in place such that it doesn't resonate quite as loudly.  I just thought I'd share my experience since the solution for my issue was a physical one rather than electrical.

jc4659, my guess is either you hit the nail on the head or it's a faulty component. Your suggestion is about the most logical given the history. Another thing I'd like to add, this unit replaced an Integra 50.3 AVR that was dead quiet. I don't believe this "hum" is normal and definitely not acceptable. I'll report the service centers response tomorrow. I believe they are a top notch shop however it's my assumption the tech may have missed something. Whatever the case it's gonna be fixed even at the cost of shipping from Los Angeles to Anthem in Canada and back.

Watching this post with interest. I have a Prima Luna integrated making hum. If you are successful getting your fixed, I'll send mine in (under warranty) to see if it is fixable.

@oldschool1

The Torus TOT MAX you bought is certainly a nice power isolation transformer. Thing is though, in the case of hum, that can very well be caused by DC on the line, and I don’t believe the Torus has a filter for that. For another $120 you might as well get an Emotiva CMX-2.
https://emotiva.com/products/accessories/cmx-2

I have one. It does work and even if it doesn’t in your particular case, it cant hurt. So essentially what I’m suggesting is use both the Torus and CMX-2. Torus plugged into CMX-2 of course.

wolf_garcia recommended a PS Audio Humbuster III. Same concept/functionality. That too would be good if you can find one, but is likely more expensive than the Emotiva.