IEC 60098:2020 pdf download – Analogue audio disk records and reproducing equipment.
This document applies to analogue audio disk records and the corresponding professional and domestic reproducing equipment. It excludes amplifiers and loudspeakers, methods of measurement for which can be found in IEC 60268-3, IEC 60268-5, IEC 60268-21 and IEC 60268-22 1 . This document specifies the characteristics that are necessary to ensure compatibility between analogue audio disk records and the corresponding reproducing equipment. It also lists and defines the most important characteristics affecting the performance of reproducing equipment, and establishes agreed methods of measurement for these characteristics 2 Normative references The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60050-806:1996, International Electrotechnical Vocabulary (IEV) – Part 806: Recording and reproduction of audio and video IEC 60050-806:1996/AMD1:2001 IEC 60050-806:1996/AMD2:2018 IEC 60263:1982, Scales and sizes for plotting frequency characteristics and polar diagrams IEC 60386:1972, Method of measurement of speed fluctuations in sound recording and reproducing equipment IEC 60417, Graphical symbols for use on equipment (available at http://www.graphical- symbols.info/equipment) IEC 61672-1:2013, Electroacoustics – Sound level meters – Part 1: Specifications IEC 62368-1:2018, Audio/video, information and communication technology equipment – Part 1: Safety requirements 3 Terms and definitions For the purposes of this document, the terms and definitions given in IEC 60050-806 and the following apply.
3.1 rated value value of a quantity used for specification purposes, established for a specified set of operating conditions of a component, device, equipment, or system Note 1 to entry: The rated value is normally the value stated by the manufacturer. [SOURCE: IEC 60050-151:2001, 151-16-08, modified – Note 1 to entry has been added.] 3.2 terminated , adj <of a circuit or connection port> connected to a specified impedance required for correct operation or for specified test conditions Note 1 to entry: ‘Specified test conditions’ can include open-circuit and short-circuit. 4 General 4.1 Scales for graphical presentation of data Linear or logarithmic scales are recommended for graphical presentation. Linear decibel scales are equivalent to logarithmic scales. Other kinds of scale, such as double logarithmic, should be avoided. When using decibel scales, the zero reference should, if possible, be the rated value. In those cases, where each of the scales refers directly to physical units, it is recommended to avoid a combination of linear and logarithmic scales. Where quantities represented by the axes are of the same kind, it is recommended that the same unit length be used for both. Linear scales with remote zero point should be avoided as far as possible. For further information, see IEC 60263. 4.2 Scales for frequency characteristics Graphs should be drawn with frequency in Hz on the x-axis with a logarithmic scale, and the level expressed in dB on the y-axis with a linear scale. The scale ratio should be such that the length representing one decade of frequency is the same as the length representing a 25 dB or a 50 dB difference in level. The preferred length per decade is 50 mm. If the size of the graph is changed, the scale ratio should be left unaltered.
6.2 Arrangement of stereophonic channels Channel orientation 6.2.1 The right-hand channel, as viewed by the audience, shall be recorded on the outer groove wall, the left-hand channel on the inner groove wall. 6.2.2 Channel phasing The phasing of the two recorded signals shall be suitable for reproduction on two-channel equipment so connected that movement of the reproducing stylus tip along the radial line through stylus tip and disk centre (as with a monophonic record) produces in-phase sound pressures at the left-hand and right-hand loudspeakers. 6.2.3 Channel levels The levels of the two recorded signals shall be suitable for reproduction on two-channel equipment, of identical channel gain, so connected that movement of the reproducing stylus along the radial line through the stylus tip and disk centre (as with a monophonic record) produces equal sound pressures at the left-hand and right-hand loudspeakers. 6.2.4 Channel polarity The polarity of the two recorded signals should preferably be suitable for reproduction on two- channel equipment so connected that movement of the reproducing stylus tip along the radial line through stylus tip and disk centre in a direction away from the disk centre shall produce compression in front of the left and right-hand loudspeakers similar to that produced by the live programme source.