Ayre QB9 DSD buzz

I have recently upgraded my QB9 to DSD. It has been running now for about 3 weeks. I can hear a hum/buzz from about a yard away.

I have tried it in different rooms, different mains cables, reversing the polarity, conecting to a mains filter as well as an issolation transformer, and even a different country, without anything making a difference.

I would like to ask if anyone else who has had an upgrade has had a similar issue? It didnt have this issue before the upgrade so I am wondering if it is "normal" or not.

I do not have an official dealer in my country and I needed to re-export and re-import when I had the upgrade. So I wanted to see if others have a similar issue before I go to this additional expense again.

Thank you

Chris