Sunn T50C hum/noise, is it normal that much noise?

[Norke]

Hi everybody!
I have a Sunn T50C since 5 years.

I would like to know if the hum at 60hz is normal for this type of amplifier?
I recorded a quick video: https://dl.dropboxusercontent.com/u/369715/sunn-t50c-noise.mp4

Turn the volume up and listen to the noise when i disable the bypass switch.
You can hear the low hum 60hz and the noise from the distortion chanel.

The same hum is also present on the clean chanel.
I tried to power it up from 3 other wall socket, still the same hum present.
I don't think it's a tube issue, maybe but almost sure not because they are pretty new.
I also tried to use a Furman power conditionner in hope to make a small change (it was spec to have "electrical noise reduction") so i gave it a try but still the same hum present.

Please ask if anything else can help find the problem or if it's normal.
Thanks for your help