[Amps] 4 x GU-81 Grounded Grid Penthodes

[Máximo EA1DDO_HK1H]

Hi all,

I´ve been told that I can use DC for filaments (instead of AC), Is that true?
If it is true, Can I use switching power supply for filaments?

Tubes GU81 needs 12.6 v and around 10A, I could use 2 x 12.6 25A switching power supply in parallel with two chokes.

Is that correct?

Is there any difference to use AC or DC for filaments?  (in grounded grid )

Thank you

73, Maximo - EA1DDO