Abstract: A video signal recorder/reproducer is used to record and/or reproduce pulse signals in successive tracks on a record medium. During recording, the pulse signals, which may, as one example, represent audio information, are interleaved with simulated horizontal and vertical synchronizing signals of the type similar to the synchronizing signals which normally are included in a composite video signal. During signal reproduction, the reproduced simulated horizontal and vertical synchronizing signals are detected and used to control the recovery of data from the reproduced pulse signals.

Abstract: A power amplifier has an input terminal supplied with a PCM (pulse code modulated) signal and a plurality of power supplies, each producing a voltage weighted according to the order of bits of the PCM-code. Switching means are controlled by the PCM input signal to connect selective ones of the power supplies in series to a load in response to the PCM signal.

Abstract: In a stereophonic sound reproduction system in which stereophonic left and right signals are treated to have a level difference therebetween for establishing a localized sound image spaced from the midpoint between left and right loudspeakers, the level difference between such left and right signals is reduced as the frequency thereof increases for improving the localization of the sound image resulting from the application of the resulting or converted left and right signals to the left and right loudspeakers.

Abstract: A binaural sound pickup assembly composed of a hollow cone-like member made of plastic resin and having a flange member on its rear portion on the larger diameter portion of the cone-like member and with a pair of microphones mounted by mounting means at both sides of the cone-like member adjacent the flange member and wherein the hollow cone-like member simulates the acoustic characteristics of a human head but which does not give the physical appearance of a human head.

Abstract: A sound pickup assembly comprising a parabolic reflector in the focal point of which is mounted a pickup and wherein the reverse side of the parabolic reflector is formed as a binaural sound pickup having a pair of microphones mounted on opposite sides of the curved surface generally on a horizontal plane and including a pair of dummy external ears mounted near the pair of microphones such that the pickup can be used as a highly directive pickup utilizing the single microphone and parabolic reflector and wherein the unit can also be utilized for binaural pickup by utilizing the two antennas and dummy ears mounted on the back surface of the unit.

Abstract: A stabilized transistor amplifier including an amplifying transistor and its biasing circuit consisting of such elements as a power supply source, diodes and resistors in which several circuit constrants of the biasing circuit at a certain pre-selected temperature are selected so as to compensate for or cancel changes in characteristic of the amplifying transistor, the power supply source, the diodes and the resistors in combination, so that the amplifier operates stably over a wide range of the ambient temperature.