Slight hum in my amp. Is this normal?

***UPDATE***
Well, my Anthem A5 made it to its birthplace safely and today I had a conversation with one of the customer service reps. Sure enough, there WAS a problem. Replace a couple bad capacitors. I don't have the hard copy report yet but I'm glad they DID find a problem, confirming I wasn't imagining the "buzz", "hum", or whatever!
As soon as I get the full report, I will list the problems here.
Also, I located an Anthem P5 for a killer price that will be replacing this A5 so it will be going up for sale if the P5 checks out healthy upon arrival. STAY TUNED !.......

Sounds encouraging! Think I'll roll the dice and see if Prima Luna can fix the hum in my unit.

Just received the service report. All of the power supply capacitors (they look like long C-cell size batteries) needed replacing. It's like a new amplifier now. I understand the caps are what fails soonest in most cases. Funny thing, I just purchased an Anthem P5 that will probably replace this A5 and if so, will be up for sale....

***UPDATE***
My Anthem A5 will be here Friday but one caveat, just picked up my (new to me) Anthem P5 from UPS. OMG is it a BEAST! Holy crap, it's 130 lbs and just connected it up. This may not be the place for a review and I cannot articulate like the pros, just sharing my latest events. The Integra 50.3, my spare unit had to pacify me while the A5 was traveling from Los Angeles to Ontario Canada, it's birthplace. Sure it didn't sound anywhere as good as the A5 and as I yearned for it's return, fond this P5. Of all places, Craigslist. It came with 4 Audioquest Diamondback XLR cables. Why not 5 is a mystery. I'm not crazy about the Diamondbacks because they look like very early versions with choke type strain reliefs that clamp/screw together. In addition, a pair of Transparent Musicwave Super speaker cables, 12 ft length. These things are HUGE! Im curious to how they will sound compared to my Audioquest Type II speaker cables. I think I'll keep the Integra as a spare and put the A5 up for sale. I hate to since it's in near mint condition however, I'd say the P5 is a nice concession. Wouldn't you?