We ask if there exist universal sampling sets of given density, which provide reconstruction or stable reconstruction of every band-limited signal whose spectrum has a small Lebesgue measure. For the stable reconstruction, we show that it is crucial whether the spectrum is compact or dense. On the other hand, the non-stable universal reconstruction is possible in general situation. To cite this article: A. Olevskii, A. Ulanovskii, C. R. Acad. Sci. Paris, Ser. I 342 (2006).