I agree.
Unplug the mains,
go have a beer or coffee.
First check all electrolytics for remaining dc.
I there is, read a book.
If not:
Check if there's a good connection from the output transformer to the speakers.
The speaker should pop when you touch the terminals with your multi meter.
Remove all your tubes, except the rectifier tube 6x4.
Plug it in,
If you know you can do it safely,
measure your voltages at the tube sockets.
then report those over here.