This paper presents a novel method for differential phase-contrast (DPC) imaging using low-brilliance X-ray sources, such as conventional X-ray tubes. The authors demonstrate that a setup consisting of three transmission gratings can efficiently produce quantitative DPC images. Unlike existing techniques, this method does not require spatial or temporal coherence and is mechanically robust, making it suitable for large fields of view. The setup includes a source grating, a phase grating, and an analyzer absorption grating. The source grating creates an array of individually coherent but mutually incoherent sources, while the phase and analyzer gratings detect the angular deviations caused by the phase object in the X-ray beam path. This method provides both absorption and phase-contrast images, making it fully compatible with conventional absorption radiography. The authors validate their method using a test sample containing polytetrafluoroethylene (PTFE) and polymethylmethacrylate (PMMA) spheres, and a biological sample, a small fish, showing that it can reveal detailed structural information in soft tissues that is not visible in conventional X-ray images. The method has potential applications in medical imaging, industrial non-destructive testing, and other fields where low-brilliance radiation sources are available.This paper presents a novel method for differential phase-contrast (DPC) imaging using low-brilliance X-ray sources, such as conventional X-ray tubes. The authors demonstrate that a setup consisting of three transmission gratings can efficiently produce quantitative DPC images. Unlike existing techniques, this method does not require spatial or temporal coherence and is mechanically robust, making it suitable for large fields of view. The setup includes a source grating, a phase grating, and an analyzer absorption grating. The source grating creates an array of individually coherent but mutually incoherent sources, while the phase and analyzer gratings detect the angular deviations caused by the phase object in the X-ray beam path. This method provides both absorption and phase-contrast images, making it fully compatible with conventional absorption radiography. The authors validate their method using a test sample containing polytetrafluoroethylene (PTFE) and polymethylmethacrylate (PMMA) spheres, and a biological sample, a small fish, showing that it can reveal detailed structural information in soft tissues that is not visible in conventional X-ray images. The method has potential applications in medical imaging, industrial non-destructive testing, and other fields where low-brilliance radiation sources are available.