question for Luxman L-590AX owners

I'll add this post, for anyone that's interested.
This afternoon I disconnected everything from the amp, my intent being to test it on another circuit. First, I took it downstairs and plugged it in there, mostly because it was on the way to where I was going. No change, still a low hum.
After that, I lugged the thing down to my shop. It's a modern building, 70 years newer than the home, and on a parallel drop with our home service. After the meter, the house and shop are two separate feeds. I shut off every breaker in the shop, other than one 20A circuit that the outlet was on. No lighting, no heat, etc. The amp still had the same hum. I'm not an electrical engineer, so I'm unsure as to how flawed this test might be. Obviously, it eliminates everything in my home. It seems to me that all it really leaves is the initial service from the power company, and the amp itself. I'm still thinking the transformer in the amp.

snapoli, thanks. I've came to the same conclusion, although certainly nothing that I can prove. Mine's quiet enough that I can't hear it from a couple feet away, and certainly not when there's music playing. It still peeves me, because it's a recent thing with it.
Appreciate everyone's input, thanks.

My dealer and Luxman said that. My dealer emailed them and the chief engineer said because they are class A they buzz when in idle.

seriously? omg you have got to be kidding me

maybe they need to hire nelson pass on a contract engineering assignment LOL

I'd be interested in hearing your thoughts, jjss49.