Pawel

hey, I had the same problem, with ennormouse buzzin, you need to open the lid on the bottom side of your amp, try to fix connections maybe some cables or plugs are not connecting, move your tubes as well maybe some pin is connected well, and finally you could try to remove one screw which might be connected to tinned path on PCB withradiator( could be a connection with ground this way sick!!!). I went these steps with mine and started working, anyway some small buzz is there but much much lower than previously however this one could come from chinese lamps. Anyway Im going to replace chinese with some correct ones.