Sound system equipment - Part 3: Amplifiers

IEC 60268-3:2018 is available as IEC 60268-3:2018 RLV which contains the International Standard and its Redline version, showing all changes of the technical content compared to the previous edition.
IEC 60268-3:2018 applies to analogue amplifiers, and the analogue parts of analogue/digital amplifiers, which form part of a sound system for professional or household applications. It specifies the characteristics that should be included in specifications of amplifiers and the corresponding methods of measurement. This part of IEC 60268 shall be used in conjunction with IEC 60268-1:1985 and IEC 60268 2:1987. This fifth edition cancels and replaces the fourth edition published in 2013. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:
a) rated condition of digital input is newly specified;
b) tolerance of rated power supply is changed;
c) maximum effective output power is appended to output characteristics list;
d) "Terms, definitions and rated values" clause is complemented.

Équipements pour systèmes électroacoustiques – Partie 3: Amplificateurs

IEC 60268-3:2018 est disponible sous forme de IEC 60268-3:2018 RLV qui contient la Norme internationale et sa version Redline, illustrant les modifications du contenu technique depuis l'édition précédente.

General Information

Status
Published
Publication Date
24-Apr-2018
Current Stage
PPUB - Publication issued
Completion Date
25-Apr-2018
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IEC 60268-3
Edition 5.0 2018-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Sound system equipment –
Part 3: Amplifiers
Équipements pour systèmes électroacoustiques –
Partie 3: Amplificateurs
IEC 60268-3:2018-04(en-fr)
---------------------- Page: 1 ----------------------
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---------------------- Page: 2 ----------------------
IEC 60268-3
Edition 5.0 2018-04
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Sound system equipment –
Part 3: Amplifiers
Équipements pour systèmes électroacoustiques –
Partie 3: Amplificateurs
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 33.160.10 ISBN 978-2-8322-6243-6

Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
---------------------- Page: 3 ----------------------
– 2 – IEC 60268-3:2018  IEC 2018
CONTENTS

FOREWORD ........................................................................................................................... 5

1 Scope .............................................................................................................................. 7

2 Normative references ...................................................................................................... 7

3 Terms, definitions and rated values ................................................................................. 8

3.1 Terms and definitions .............................................................................................. 8

3.2 Rated values ........................................................................................................... 9

4 Conditions ....................................................................................................................... 9

4.1 Rated conditions and standard measuring conditions .............................................. 9

4.1.1 Overview ......................................................................................................... 9

4.1.2 Rated conditions ............................................................................................ 10

4.1.3 Standard measuring conditions ...................................................................... 11

4.2 Other conditions.................................................................................................... 11

5 Classes of operation ...................................................................................................... 11

6 Interchangeable parts .................................................................................................... 11

7 Automatic controls ......................................................................................................... 11

8 Power supply ................................................................................................................. 12

9 Position of the volume controls ...................................................................................... 12

10 Pre-conditioning for measurements ............................................................................... 12

11 Series of measurements ................................................................................................ 12

12 Variable consumption apparatus .................................................................................... 12

13 Marking ......................................................................................................................... 13

14 Operating environment .................................................................................................. 13

15 Characteristics to be specified, and their methods of measurement ............................... 13

15.1 Power supply characteristics ................................................................................. 13

15.1.1 Characteristics to be specified ....................................................................... 13

15.1.2 Method of measurement ................................................................................ 14

15.2 Tolerance of (long-term) power supply voltage variations ...................................... 14

15.2.1 Characteristic to be specified ......................................................................... 14

15.2.2 Methods of measurement .............................................................................. 15

15.3 Tolerance of power supply frequency variations .................................................... 15

15.3.1 Characteristics to be specified ....................................................................... 15

15.3.2 Methods of measurement .............................................................................. 16

15.4 Tolerance of power supply harmonics and ripple ................................................... 16

15.4.1 Characteristics to be specified ....................................................................... 16

15.4.2 Methods of measurement .............................................................................. 17

15.5 Input characteristics .............................................................................................. 17

15.5.1 Rated source impedance, characteristic to be specified ................................. 17

15.5.2 Input impedance ............................................................................................ 17

15.5.3 Rated source e.m.f., characteristic to be specified ......................................... 19

15.5.4 Minimum source e.m.f. for rated distortion-limited output voltage ................... 19

15.6 Output characteristics ........................................................................................... 19

15.6.1 Rated load impedance, characteristic to be specified ..................................... 19

15.6.2 Output source impedance .............................................................................. 20

15.6.3 Output voltage and power (distortion-limited) ................................................. 20

15.6.4 Maximum effective output power (distortion-limited at 10 %) .......................... 22

---------------------- Page: 4 ----------------------
IEC 60268-3:2018  IEC 2018 – 3 –

15.6.5 Regulation ..................................................................................................... 23

15.6.6 Overload restoring time ................................................................................. 24

15.7 Limiting characteristics ......................................................................................... 24

15.7.1 Overload source e.m.f. .................................................................................. 24

15.7.2 Short-term maximum output voltage and power ............................................. 24

15.7.3 Long-term maximum output voltage and power .............................................. 25

15.7.4 Temperature-limited output power ................................................................. 26

15.8 Characteristics of protection circuits ..................................................................... 27

15.8.1 General ......................................................................................................... 27

15.8.2 Protection against potentially damaging combinations of output voltage

and current .................................................................................................... 27

15.8.3 Characteristics of d.c. offset protection circuits .............................................. 28

15.9 Sustaining-time for rated (distortion-limited) output voltage or power .................... 29

15.9.1 General ......................................................................................................... 29

15.9.2 Characteristic to be specified ......................................................................... 31

15.9.3 Method of measurement ................................................................................ 31

15.10 Gain ...................................................................................................................... 31

15.10.1 Voltage gain and e.m.f. gain .......................................................................... 31

15.10.2 Maximum e.m.f. gain ..................................................................................... 31

15.10.3 Attenuation characteristic of the volume control ............................................. 32

15.10.4 Attenuation characteristic of balance controls for multi-channel

equipment...................................................................................................... 32

15.11 Response ............................................................................................................. 33

15.11.1 Gain-frequency response ............................................................................... 33

15.11.2 Gain-limited effective frequency range ........................................................... 33

15.11.3 Distortion-limited effective frequency range ................................................... 34

15.11.4 Phase-frequency response ............................................................................ 34

15.12 Amplitude non-linearity ......................................................................................... 34

15.12.1 General ......................................................................................................... 34

15.12.2 Rated total harmonic distortion, characteristic to be specified ........................ 35

15.12.3 Total harmonic distortion under standard measuring conditions ..................... 35

15.12.4 Total harmonic distortion as a function of amplitude and frequency ............... 35

15.12.5 Harmonic distortion of the nth order under standard measuring

conditions ...................................................................................................... 36

15.12.6 Harmonic distortion of the nth order as a function of amplitude and

frequency ...................................................................................................... 37

15.12.7 Modulation distortion of the nth order (where n = 2 or n = 3) .......................... 37

15.12.8 Difference-frequency distortion of the nth order (where n = 2 or n = 3) ........... 39

15.12.9 Dynamic intermodulation distortion (DIM) ...................................................... 40

15.12.10 Total difference frequency distortion .............................................................. 42

15.12.11 Weighted total harmonic distortion ................................................................. 44

15.13 Noise .................................................................................................................... 44

15.13.1 Characteristic to be specified ......................................................................... 44

15.13.2 Method of measurement ................................................................................ 45

15.14 Hum ...................................................................................................................... 45

15.14.1 General ......................................................................................................... 45

15.14.2 Characteristics to be specified ....................................................................... 45

15.14.3 Method of measurement ................................................................................ 46

15.15 Balanced inputs and outputs ................................................................................. 46

15.15.1 Balance of the input ....................................................................................... 46

---------------------- Page: 5 ----------------------
– 4 – IEC 60268-3:2018  IEC 2018

15.15.2 Overload (distortion-limited) peak-to-peak common-mode input voltage ......... 47

15.15.3 Balance of the output ..................................................................................... 48

15.16 Cross-talk and separation in multi-channel amplifiers ............................................ 49

15.16.1 Characteristics to be specified ....................................................................... 49

15.16.2 Method of measurement ................................................................................ 50

15.17 Gain and phase differences between channels in multi-channel amplifiers ............ 51

15.17.1 Gain difference .............................................................................................. 51

15.17.2 Phase difference............................................................................................ 51

15.18 Dimensions and mass, characteristics to be specified ........................................... 52

Annex A (informative) Balanced interfaces ........................................................................... 58

Annex B (informative) Specification of a multi-channel amplifier........................................... 59

B.1 General ................................................................................................................. 59

B.2 Example specification of a 5.1 channel amplifier ................................................... 59

B.3 Example specification of a 5 channel amplifier ...................................................... 59

Bibliography .......................................................................................................................... 61

Figure 1 – Example block diagram for multi-channel amplifier ............................................... 52

Figure 2 – Connection diagram of equipment for digital input ................................................ 52

Figure 3 – Arrangements for the Class D amplifier ................................................................ 53

Figure 4 – Arrangements for measuring input impedance ...................................................... 53

Figure 5 – Oscillogram when measuring overload restoring time ........................................... 54

Figure 6 – Protection against potentially damaging combinations of output voltage and

current .................................................................................................................................. 55

Figure 7 – Arrangement for combining two input signals ....................................................... 55

Figure 8 – Frequency spectrum below 30 kHz of the signal for measuring dynamic

intermodulation distortion ...................................................................................................... 56

Figure 9 – Arrangement for measuring the balance of a balanced input ................................ 56

Figure 10 – Arrangement for measuring the internal impedance balance of a balanced

output ................................................................................................................................... 56

Figure 11 – Arrangement for measuring the voltage symmetry of a balanced output ............. 57

Figure B.1 – Block diagram for a 5.1 channel surround amplifier ........................................... 59

Figure B.2 – Block diagram for a 5 channel surround amplifier .............................................. 60

Table 1 – Different rated total harmonic distortion and rated distortion-limited output

power specifications for the same amplifier ........................................................................... 30

Table 2 – Distortion components due to dynamic intermodulation distortion falling in

the frequency range up to 20 kHz ......................................................................................... 41

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IEC 60268-3:2018  IEC 2018 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
______________
SOUND SYSTEM EQUIPMENT –
Part 3: Amplifiers
FOREWORD

1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising

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patent rights. IEC shall not be held responsible for identifying any or all such patent rights.

International Standard IEC 60268-3 has been prepared by IEC technical committee 100:

Audio, video and multimedia systems and equipment.

This fifth edition cancels and replaces the fourth edition published in 2013. This edition

constitutes a technical revision.

This edition includes the following significant technical changes with respect to the previous

edition:
a) rated condition of digital input is newly specified;
b) tolerance of rated power supply is changed;
c) maximum effective output power is appended to output characteristics list;
d) "Terms, definitions and rated values" clause is complemented.

This bilingual version (2018-12) corresponds to the English version, published in 2018-04.

---------------------- Page: 7 ----------------------
– 6 – IEC 60268-3:2018  IEC 2018
The text of this standard is based on the following documents:
CDV Report on voting
100/2960/CDV 100/3069/RVC

Full information on the voting for the approval of this standard can be found in the report on

voting indicated in the above table.

This document has been drafted in accordance with the ISO/IEC Directives, Part 2.

A list of all parts in the IEC 60268 series, published under the general title Sound system

equipment, can be found on the IEC website.
This part of IEC 60268 shall be used in conjunction with IEC 60268-1:1985 and
IEC 60268-2:1987.

The committee has decided that the contents of this document will remain unchanged until the

stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to

the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
The French version of this standard has not been voted upon.
---------------------- Page: 8 ----------------------
IEC 60268-3:2018  IEC 2018 – 7 –
SOUND SYSTEM EQUIPMENT –
Part 3: Amplifiers
1 Scope
This part of IEC 60268 applies to analogue amplifiers, and the analogue parts of

analogue/digital amplifiers, which form part of a sound system for professional or household

applications. It specifies the characteristics that should be included in specifications of

amplifiers and the corresponding methods of measurement.

NOTE The methods of measurement for digital amplifiers and similar equipment are given in IEC 61606 [1] .

In general, the specified methods of measurement are those which are seen to be most

directly related to the characteristics. This does not exclude the use of other methods that

give equivalent results.

In general, the methods are based on the simplest measuring equipment which can provide

useful results. This does not exclude the use of more complex equipment that can give higher

accuracy and/or allow automatic measurement and recording of results.

Rated conditions and standard measuring conditions are specified in order to allow

measurements to be reliably repeated.
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 60065:2014, Audio, video and similar electronic apparatus – Safety requirements

IEC 60268-1:1985, Sound system equipment – Part 1: General
IEC 60268-1:1985/AMD1:1988
IEC 60268-1:1985/AMD2:1988

IEC 60268-2:1987, Sound system equipment – Part 2: Explanation of general terms and

calculation methods
Amendment 1:1991

IEC 60417:2002, Graphical symbols for use on equipment – 12-month subscription to

regularly updated online database comprising all graphical symbols published in IEC 60417

IEC 60958:2016 (all parts), Series, Digital audio interface
__________
Numbers in square brackets refer to the Bibliography.
---------------------- Page: 9 ----------------------
– 8 – IEC 60268-3:2018  IEC 2018

IEC 61000-4-13:2002, Electromagnetic compatibility (EMC) – Part 4-13: Testing and

measurement techniques – Harmonics and interharmonics including mains signalling at a.c.

power port, low frequency immunity tests
IEC 61000-4-13:2002/AMD1:2009
IEC 61000-4-13:2002/AMD2:2015

IEC 61000-4-17:1999, Electromagnetic Compatibility (EMC) – Part 4-17: Testing and

measurement techniques – Ripple on d.c. input power port immunity test
IEC 61000-4-17:1999/AMD1:2001
IEC 61000-4-17:1999/AMD2:2008

IEC 61000-4-29:2000, Electromagnetic Compatibility (EMC) – Part 4-29: Testing and

measurement techniques – Voltage dips, short interruptions and voltage variations on d.c.

input power ports immunity tests
IEC 61606-1:2009, Audio and audiovisual equipment – Digital audio parts – Basic
measurement methods of audio characteristics – Part 1: General
IEC 61883-6:2014, Consumer audio/v
...

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