tube amp power transformer
That is not a schematic. 

Yes, you can use it, with a full-wave bridge rectifier. Instead of grounding the (nonexistent) center tap of the transformer you ground the minus side of the bridge rectifier. 

Similarly one side of the filament should be grounded rather than the (nonexistent) filament winding centre tap. 







simulate this circuit &ndash; Schematic created using CircuitLab

Be extremely careful and don't electrocute yourself.