The change in the irradiance spectrum of the Sun from 1700 to the last solar minimum is determined and compared to the change in the spectrum between activity minimum and maximum. For this purpose we have used detailed model flux spectra of solar magnetic features. Also, time-series of the solar spectral irradiance since 1700 in different wavelength bands are reconstructed. We expect that these reconstructions are more accurate than previously published ones, although they suffer (like all reconstructions of solar irradiance on such time-scales) from uncertainties in our knowledge of the evolution of the solar network with time.