Hello all from Ray living in Wales, UK (well, from a tiny island called Anglesey off the Welsh coast). I have been looking at another amp builder’s web site who provides kits and schematics but for power he uses transformers for B+ via full or half wave diode based rectification rather than tube rectification and a separate low voltage DC supply (wall wart) for filament heating, enabling easy switching between 6 and 12 volts by simply plugging in an alternate supply, enabling some tube swapping.
I can see some advantages, mainly a simpler power supply - but what others are there, and are these outweighed by disadvantages?
So, 2 questions...................
All the tubes I use have 6 volt heaters, so using a wall wart for me is rather dumb. We too, have to keep in mind, some of the heaters on the bigger tubes require 2A each. In some situations you might need 6 volts with 10-12 amps of current.
I'm guessing you are asking about a rectifier tube vs. a full wave bridge rectifier? A tube always has more losses than a solid state rectifier bridge. I think if you are building from your junk pile you use what you have to get your desired B+. Some claim to hear a difference between a tube and a solid state rectifier, I can't.
Typically the majority of toroidal audio power transformers (which are cheaper, by about half, than a conventional audio power transformer) do not have the 5 volt winding for a rectifier tube so the choice has been made for you.