In some embodiments, an apparatus and a system, as well as a method and an article, may include receiving a received signal, such as a substantially sinusoidal signal, provided by a driven element, such as a magnetostrictive device, coupled to a non-atmospheric medium and an amplifier having substantially zero quiescent current in the absence of an input signal, wherein the amplifier is to receive a pulse modulated wave comprising an original signal substantially similar to the received signal.