SOOOOO true. Was 2am when i finally fired up my first KGSS build and Boom! a couple of resistors (RN60D) coatings was blown clean off along with a nasty smell. Realised i had connected the HV wires on one side of the amp board the wrong way round....Twat! Never got round to repairing the damage i just use the board to practice de-soldering.