I think your can make 2x1.41x120 = 338 V dc but I don't want to risk
my life by not using a safety transformer!
Of course savety is important, but there are other means to get there than
just using a safety transformer. Even most of our household equipement runs
directly on the mains. The key is to isolate the mains (or any other HV)
from the 'touchable' parts of the equipement. For a PA this would mean that
is is mounted within a box and that input and output are properly isolated
from any HV. As in most cases the output of the PA has a transformer
(impedance matching) the antenna out is well isolated. The driver input can
either be isolated by another transformer (linear PA) or by an octocoupler
(square wave driven class D PA).
73, Rik ON7YD