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

No issues here. Maybe try a friend's home to double check that's it's not a power line or DC on power line issue?
Thanks for your reply Nkbg
I did try it in another home, with the same result. I sent it back to the dealers and they agreed the buzz was unacceptable. What they feel is that as we need 230vac over here this means a larger transformer is required which might be exacerbating the issue. Anyway, a new transformer is on order which should hopefully sort it out.
Hi Chris,
i also have the DSD and use it with 230 v in Europe. I can confirm the buzzing too. Did the change of transformer help? What was changed exactly? 
Thanks for a feedback
Best regards
I have since sold my Ayre QB-9 DSD DAC but it did “stop working” and had to be retuned to the factory for a transformer repair.  As you noted, I wonder if your buzzing is due to a transformer issue and am hoping your new transformer solves the buzzing problem. Please keep us posted.  

I was told the Ayre Codex DAC employs a very high quality linear power supply. This is why it sounds so good in balanced mode. This also means that the voltage is fixed.

Based on the above two description, its sounds like both Ayre Codex DAC’s are having buzzing problems on 220v.  My best guess is both these units are having transformer problems and that factory repairs are required.