I knew 1 and 4 were for filaments but did not know about the +/- . Thanks
I should probably explain myself better. When I made the comment about 'even if the filaments were reversed' I was referring to the A and B bat connection, as Norm Leal mentioned. The filament end connected to B- will be the 'ground' end (or B bat 'return') and the other, then acts as a 'bias'. I.E. If A- is connected to B- then the other side of the filament is positive with respect to B- and vice versa. Datasheet grid bias numbers are based on filament - at 'ground'.
I was simply making the case it did not seem like the tubes could be pulling enough current to kill B+ 'even if wired wrong'.
DC filaments, like on the 01, are polarity marked but whether that affects bias I am nore sure because I have always observed the marked polarity. The conventional visualization of a 'filament' is it being simply a wire, coated or not, that gets hot so it would not seem to matter which end one picks as '-', but I'm also not sure that is, in fact, the practical reality of things. I mean, since one end 'must' be -, with emission and current distribution not constant across the filament, one can imagine the tube designer might do something 'special' because of it but that level of manufacturing nuance exceeds my expertise. Observing the marked polarity, however, eliminates the doubt.