Hello Al,
A directly heated triode requires it's own dedicated filament winding unlike an indirectly heated triode. If you look at the bottom of a power transformer(not a plate transformer mind you)you will see individual windings for the output, signal & rectifier tubes. Indirectly heated driver tubes such as the 6sn7,6sl7 etc can share a 6,3v/2 amp winding. Of course the rectifier tube has it's own winding as well. It's typically 5v/3a.
You can use a 5v/2a tube on a 3 amp winding, but you can't use a 5u4g on a 5v/2a winding. Since this thread is largely about the "Franks", lets try to keep in mind that these two circuits are completely different from one another, and that we don't have a "one size fits all" situation here. Hope this sheds some light up here.
Best,
George
A directly heated triode requires it's own dedicated filament winding unlike an indirectly heated triode. If you look at the bottom of a power transformer(not a plate transformer mind you)you will see individual windings for the output, signal & rectifier tubes. Indirectly heated driver tubes such as the 6sn7,6sl7 etc can share a 6,3v/2 amp winding. Of course the rectifier tube has it's own winding as well. It's typically 5v/3a.
You can use a 5v/2a tube on a 3 amp winding, but you can't use a 5u4g on a 5v/2a winding. Since this thread is largely about the "Franks", lets try to keep in mind that these two circuits are completely different from one another, and that we don't have a "one size fits all" situation here. Hope this sheds some light up here.
Best,
George