A circuit for amplifying a signal representing a variation in resistance of a variable resistance comprising at least one first load linked to an output terminal of a first transistor whose other terminal is associated with a variable resistance, in such a way as to allow the recovery of the amplified signal at the terminals of the first load. The anode active material layer is a multi-layered thin film formed by stacking a silver layer and a silicon-metal layer having silicon dispersed in a base made from metal reacting with silicon while not reacting with lithium. The system and methods are capable of detecting audible alert signals generated by far away smoke, fire, and carbon monoxide detectors. The clock signal supply circuit is operable to selectively vary a phase offset between the edge and data clock signals.