[Amps] HELP Modifications for a Kenwood TL922

[BEHIELS JEAN-PIERRE]

    Dr;

    I have from the scrap and in repair a old Kenwood TL922 amplifier.
    I will do some demonstration and technical test for a school educational 
=
    object in electronics.
    But I only have obtained one old and used 3-500Z tube.
    Question is can I made some modifications to use this old TL922 with =
    only one 3-500Z tube. =20
    I see in first order that the filaments of both 3-500z tubes are =
    originally supplied in series with a 12 VAC transformer.
    That means in first place I already have to change the filament =
    transformer into one of 5 VAC.
    But what you think about the rest of the RF-circuit should I have to =
    change also many of the values of the PI-filter network and so on.
    I really appreciate to receive your ideas around this subject and of it 
=
    is usefull to do sutch modification.


    Regards Jean OP4F.