Complex sentence: These tubes drive current through the two halves of the primary winding of a center-tapped output transformer in such a way that the signal currents add, while the distortion signals due to the non-linear characteristic curves of the tubes subtract.
Split into simpler sentences: These tubes drive current through the two halves of the primary winding of a center-tapped output transformer. Signal currents add, while the distortion signals due to the non-linear characteristic curves of the tubes subtract.