Luxman Class A Integrated Slight Buzzing Noise

Deedo--I have found your posts very interesting and illuminating. Transformer hum and buzz has, off and on, bothered me for years. All the way back to when I owned an Adcom 535 (long time ago). I had a big Nackamichi for about a day (re-badged Threshold), that also hummed. And a big Sony from the old ES line that didn't. I had concluded that it was crap on the line coming into the house, combined with the design of the transformer--i.e. that toroidals were a lot more prone to it than other shapes/designs (the Sony had EIs). I've steered away from toroidals for a long time, first with a Cary and now with an Ayre. (I discarded Plinius as an option because there was a lot of anecdotal evidence on line about humming.) The idea that it all depends on the size/weight, the materials, and the exact construction, rather than the basic shape/configuration, is something of a revelation.

I have about 200 hours on my L590ax. There is no hum whatsoever. I'm using an Isotek Acquarius for power conditioning.

Excellent detective work. My C-J tube amp has a bit of a hum when no music is playing. Some call it tube rush. I don't worry about it because it does not interfere or create issues when I play music. Does your hum become undetectable when you play music?

Bump-- my second hand Luxman 550ax has that slight hum/buzz from inside the unit case. You can def hear something 8ft away. Its not bad but if you lock on to it--will bother you!! Any solutions since 2015??

A SS amp I use for a backup and/or outdoor speakers (mostly the latter) had a transformer hum that a local repair dude said wasn't fixable...lame...but I found a PS Audio Humbuster III online someplace and that fixed it fine. Although those are discontinued I would think somebody makes a similar gizmo.