BAT VK75SE buzz and humming ?? help..

Hello all, received a BAT VK-75SE which by the way is a lovely Tube amp for those that are not aware.

Unfortunatly I have plugged it in and have had a constant buzz since day one.. the buzzing remains even when Interconnects are removed and ground is lifted

I have :

1. Plugged the amp in a different part of the house- No Change

2. Changed Speakers and speaker cable - No Change
3. Changed PowerCord and Lifted ground - No Change

The amp itself is dead quiet, no transformer hum or anything.. could tubes do this ? ..

thanks all in advance !

Matt