Abstract: A highly accurate resistor for audio/video signal circuits is disclosed, and includes a substantially cylindrical substrate composed of dielectric material, such as ceramics, and a film layer of resistive material, such as tantalum with high purity. The film layer is arranged exclusively on the outer peripheral surface of the substrate such that the dielectric material is exposed on both end surfaces of the substrate. Undesirable eddy currents are prevented or suppressed from being induced on the end surfaces of the substrate as audio/video signal current is supplied to and conducted through the resistor, realizing a significant improvement in the high fidelity or definition of the reproduced sound/picture image.

Abstract: An apparatus for shielding an audio signal circuit is disclosed, which comprises a shielding member (13, 21, 31, 41, 42) surrounding a signal conductor (11). According to the present invention, the shielding member has an electrically discontinuous portion so as not to form a closed circuit within the cross section of the signal conductor (11). It is thus possible to prevent the signal current flowing through the signal conductor (11) from inducing a secondary current in the shielding member, without impairing the properties of the shielding member by which the signal conductor (11) is effectively shielded against any external electromagnetic field.

Abstract: A constant-voltage power source device for a highly accurate electric circuit, connected to an A.C. power source, capable of minimizing size of the current loop, making the ground line current constant even when the load current varies, and having a high noise elimination ratio as well as a low output impedance.The device comprises a constant-current circuit connected in series with the load, and in parallel therewith a constant-voltage circuit including a control amplifier which controls the current flowing therethrough so that sum of this current and the output current of the device supplied to the load equals to the output current of the constant-current circuit.

Abstract: A pickup cartridge for reproducing disk-shaped record carriers having a spiral groove as an information track carrying audio and/or video information. A horn-shaped resilient seal member prevents entry of foreign matters, such as moisture or dust into the cartridge casing, through which member a cantilever carrying at its front end a stylus extends. This seal member keeps characteristics of the cartridge transducer within the casing always optimum.