question for Luxman L-590AX owners


I own the subject amp, have had it for 3-4 years. I recently noticed a low hum or buzz coming from the amp itself (not the speakers), and would swear that it has been dead quiet up until now. You have to have your head right down beside it to hear it. I'd like to hear what other owners have to say. Are your amps completely quiet? Seems like I may have developed an issue. Thanks in advance, and Merry Christmas.
builder3
I guess I must be lucky then. Zero hum or buzz on my AXII even if I put my ear right next to it. 
I was the same, until a couple months ago. I'd like to have the newer AXII, even though I choke at the money, but a couple guys here say theirs have the same hum. I bought this amp used, it's immaculate, think it was $4300. Not sure what I'm going to do, it's eating at me, lol. Might be nice to hear something from Luxman, too, obviously.
Thanks to everyone for the input.
Haha, erik_squires suggested the same device halfway up the thread.

Dang the whole issue is troublesome though. I was seriously considering targeting an L590axii for my main system and an L550axii for my secondary because I know the SQ is up my alley with my Spendor speakers but now I just don’t know. This doesn’t sound like an isolated incident.

That said, I wonder how prevalent it is? Does it affect 5% of units or 40%? It’s a rhetorical question since probably only Luxman knows and sounds like they’re not talking, also troubling.

Anyway, I’ll continue to follow here and hope that tweak works out for you OP.
If other Luxman class A integrated owners have also experienced the hum, post up!