This part of IEC 61606 is applicable to the basic methods of measurement of the audio characteristics of the digital audio part of audio and audiovisual equipment for all of consumer use, professional use and personal computer. The common measuring conditions and methods, described in this standard, are used for the measurement of the performance characteristics of equipment having an audio bandwidth equal to approximately one-half of the sampling frequency of a system, where the audio information is processed in the form of digital data. CD players, DAT recorders, digital amplifiers, digital sound broadcast receivers and television broadcast receivers with digital sound are examples. This standard describes test methods for equipment which has digital input with analogue output and analogue input with digital output. Future revisions of this standard will cover digital-in/digital-out and analogue-in/analogue-out tests. This standard does not apply to a lossy compression signal and also does not apply to power amplifiers. NOTE 1 A digital audio system having an analogue input and an analogue output with digital signal processing may have different characteristics from those of a pure analogue audio system due to sampling of the audio signal and performance of incorporated A/D and D/A converters. Measurement methods described in IEC 60268-3 may not give correct results when applied to a digital system. NOTE 2 The methods described are mostly based on sampling frequencies of 32 kHz and higher. NOTE 3 For tests of those systems of digital-in – digital-out, and analogue-in – analogue-out tests, refer to AES17. NOTE 4 This standard is planned to harmonize with the first edition of IEC 61606 (1997)1, AES17 and EIAJ CP- 2i50.