Fe_{73.5-x}Si_{13.5}B_9Cu_1Nb_3Mn_x (x=1, 3÷15) amorphous alloys were studied by means of Mössbauer spectroscopy, as-quenched and after annealing. The basic alloys show stronger magnetic ordering for small values of x, than for larger x. The initially amorphous phase and the final nanocrystalline structure were determined with X-ray diffraction. The alloys were shown, by scanning calorimetry, to suffer different phase transformations, when heated.