The NF5ex is a tremendous value, achieving excellent results with its round wire exciter coil and spherical S10 iron yoke. The bass from this circuit is incredibly powerful, with very natural dynamics and microtonal resolution. It takes the characteristic Naturflux sound and cranks it up to an even higher level of power and finesses, with impressive slam and authority, incidentally taking all the tonal charm and subtlety of the Naturflux aesthetic to a still higher level of perfection.