The magnetoelectric (ME) effect of piezoelectric-magnetostrictive laminate composites, which is a product tensor, has been studied. Based on piezoelectric and piezomagnetic constituent equations, the longitudinal-mode vibration and equivalent circuits have been derived. The effective magnetoelectric coupling coefficient, voltage-gain, and output efficiency have been determined. Our results show: (i) that there is an extreme high voltage gain effect of > 260 under resonance drive: the induced ME voltage is much higher than the input voltage to the coils for magnetic excitation; (ii) that there is an optimum ratio of the piezoelectric to piezomagnetic layer thicknesses, which results in maximum effective magnetoelectric coupling; and (iii) that the maximum output efficiency of magnetoelectric laminate at resonance drive is similar to 98%, if eddy currents are neglected. This high ME voltage gain effect offers potential for power transformer applications. (c) 2006 Springer Science + Business Media, Inc.