Hegel hum?

Received my H400 today to replace my H390, watched YouTube videos saying power supply now has a DC blocker built in. I had a lot of DC hum from the H390 but my Puritan PSM156 killed most of it. However the new H400 has a low pulsing hum which I am surprised to hear given what was said in the reviews, one of which said it was now dead silent (the Canadian guy Mr Chibbs I think) It is odd as it pulses and can be heard in my dead silent room. It is plugged into the Puritan but even on a normal mains socket still the same low level hum. Have played it only for a hour or so and the improvement in sound is apparent over the H390 but quite annoyed that it still hums. Seems a couple of people in this thread have the same issue? Dave543210 is describing exactly what I am hearing so maybe they haven’t made the H400 silent after all, sigh…

Unfortunately I seem to have really dirty mains, had a H590 on demo, which hummed and then a loner H390 again hummed and finally my new H390 which again hummed, definitely DC issues which the Puritan drastically reduced (great equipment shame about the price). The H400 seems to have a buzz and I am wondering if its from the secondary small transformer and I am betting it doesn’t get the same mains feed as the main which has the DC blocker and is quiet. So now I think the culprit is the small transformer that I think is used to power sundry stuff. The unit was an ex demo and will contact the dealer but will give it a few days, maybe will ping Hegel direct. When I put my ear close to the amp the buzz is on the right side as you look at the amp from the front which again indicates the small transformer - perhaps it is picking up DC that the Puritan isnt killing. The H390 hum was the big transformer and the H400 is silent in that respect so am convinced its the small transformer. @baconboy do you think the buzz is the small transformer in your unit, mine is constant and maybe its just "normal" transformer hum