Actually, if you ever get the chance to try out a pre-modern piano, you will find these fortepianos have more sustaining ability than you would think. If Beethoven wanted blending, he wrote it (see Tempest Sonata 1st mvt, Beethoven has an interesting pedal marking in one of the slow passages). But I was under the impression senza sordino means without mutes, or the soft pedal. Correct me if I'm wrong.