PURPOSE: To obtain a recorded signal reproducer having a high S/N and high productivity, by providing an amplifying circuit means between a reproducing head and the primary coil to amplify the output of the reproducing head and obtaining a power supply with an optical electromotive force means to drive said amplifying circuit means.

CONSTITUTION: An amplifying circuit means 12 contains a printed distributing board 15 having a necessary circuit parts 14 and supplies and amplifies the reproduced signal given from a magnetic head H to apply it to a primary coil 9 of a transformer TR. The board 15 contains wirings on its both sides and receives the power from an optical electromotive force means 13 on its single side to transmit the power to the other side having the parts 14 via a through- hole. The output of the means 13 which is energized by a light source 19 is stabilized by a stabilizing circuit 20 to be applied to a power supply for the amplifier 12 as well as transistors Q1 and Q2.