An X-ray emitter has an X-ray tube which contains a vacuum envelope in which an emitter and an anode are disposed. The emitter can be heated by an external flat emitter filament supply. Accordingly the emitter is configured as a filament emitter and an interface circuit is arranged between the filament emitter and the flat emitter filament supply. In this manner, a flat-emitter-based X-ray emitter can be replaced by a filament-emitter-based X-ray emitter in an X-ray emitter system without any configuration changes.