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
Hey, guys, thanks to you all for taking the time to help. Your answers give me some food for thought. We have one dimmer in the house, on a light that's seldom used, I don't think that could be it. Two things come to mind, after reading your replies. Number one, we have a lot of Christmas lights and decorations up at the moments, all indoors, most of it on timers, and controlled electronically, etc. Not sure if they are causing any issues, but they'll be gone within the week, so maybe I'll see a change. The second change is my wireless router. It's the same one for a few years, but I recently made some alterations, at the advice of the phone tech. Almost everything was hard wired, and I was having service issues. He told me the hardwiring was actually causing interference with the signal, and advised me to unhook everything and let it operate wirelessly (less the TV that's 3 rooms away). This was counterintuitive to me, and I was skeptical, but everything was definitely improved after I unhooked the cabling. My first step is wait and see if there's an improvement after the Christmas lights go away.
wahoostewjr, I would like to say I'm positive I never had the hum before, but can't. It's that quiet. It sounds exactly like the low hum in my heater/thermostat combo down in my shop. Nearly unnoticeable, unless there's not a lick of noise anyplace, and you listen very closely. My amp also runs pretty warm. From comments here about other pieces of equipment, sounds like some other stuff runs a lot hotter.
Thanks again!
I have smaller brother... Sister..?  The 550ax2 and a class as well. No hum I've noticed but I'm in a city with good supply and 230v here (which may be a reason) 

As for heat mine gets warm to touch but I can still hold hand to case after hours. A bonus in fact for cold Scotland 
No hum but I’ve trigerred the protection circuit several times now as the amp automatically shut down by itself. The system was played continuously for several hours, sometimes above 10 hours in a day when it happened. At least I am aware the protection circuit feature of the amp is working and the unit is protected from the heat that it produces.

It sounds magnificent by the way.
  1. Buy a DC blocker in Bulgaria , it works fine for me . I,ts a small 122,- dollar investment. Be sure to order the right version...Be sure to order the 2v 6 diodes version.https://www.atlhifi.com/shop/fully-assembled-devices/dc-blocker-trap-filter-assembled-in-case/
I have this one, made my Hi-Fi sound better with blacker background and the hum I had from my class A power amp trough my speakers disappeared, mine is with 8 outlets, beautiful made.
https://harmonydesign.se/produkt/dct-90/
The guy behind the company (Mattias) is very friendly and competent, answered a lot of my questions.
Why not shoot him a mail, sure he can help.