[Amps] Switching PS for filaments?

[Tom W8JI]

> One problem that can arise is if the psu doesn't like 
> providing the excess amps when you first switch because 
> the filament is cold. I got a 5v 15A one for my 4CX1000 
> (yet to be built) amp: it won't start with a cold 
> filament. It's possible some constructive step start or 
> voltage ramping is needed.

While being fanatical about filament voltage in an effort to 
prevent the 1 in 1000 tube filament failure, the same 
attitude should compel users to add length to the warm up 
time. After all, the cathode will heat slower and won't ramp 
up in temperature as fast.

I wonder how many people deep into the quest for perfection 
think of that?

73 Tom