SIST EN 61938:2013

SLOVENSKI STANDARD
SIST EN 61938:2013
01-november-2013
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SIST EN 61938:1999
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Multimedia systems - Guide to the recommended characteristics of analogue interfaces
to achieve interoperability (IEC 61938:2013)
Multimedia Systeme - Leitfaden für empfohlene Charakteristiken analoger Schnittstellen
zur Erreichung von Kompatibilität (IEC 61938:2013)
Systèmes multimédia - Guide des caractéristiques recommandées des interfaces
analogiques permettant d'obtenir l'interopérabilité (CEI 61938:2013)
Ta slovenski standard je istoveten z: EN 61938:2013
ICS:
33.160.60 9HþSUHGVWDYQLPXOWLPHGLMVNL Multimedia systems and
VLVWHPLLQRSUHPD]D teleconferencing equipment
WHOHNRQIHUHQFH
35.200 Vmesniška in povezovalna Interface and interconnection
oprema equipment
SIST EN 61938:2013 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST EN 61938:2013

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SIST EN 61938:2013

EUROPEAN STANDARD
EN 61938

NORME EUROPÉENNE
September 2013
EUROPÄISCHE NORM

ICS 33.160.01; 35.200 Supersedes EN 61938:1997


English version


Multimedia systems -
Guide to the recommended characteristics
of analogue interfaces to achieve interoperability
(IEC 61938:2013)


Systèmes multimédia -  Multimedia Systeme -
Guide des caractéristiques Leitfaden für empfohlene Charakteristiken
recommandées des interfaces analoger Schnittstellen zur Erreichung von
analogiques permettant d'obtenir Kompatibilität
l'interopérabilité (IEC 61938:2013)
(CEI 61938:2013)




This European Standard was approved by CENELEC on 2013-08-01. CENELEC members are bound to comply
with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the CEN-CENELEC Management Centre or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and notified
to the CEN-CENELEC Management Centre has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus,
the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany,
Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland,
Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

CEN-CENELEC Management Centre: Avenue Marnix 17, B - 1000 Brussels


© 2013 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 61938:2013 E

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SIST EN 61938:2013
EN 61938:2013 - 2 -
Foreword
The text of document 100/2130/FDIS, future edition 2 of IEC 61938, prepared by IEC/TC 100 "Audio,
video and multimedia systems and equipment" was submitted to the IEC-CENELEC parallel vote and
approved by CENELEC as EN 61938:2013.

The following dates are fixed:
(dop) 2014-05-01
• latest date by which the document has to be
implemented at national level by
publication of an identical national
standard or by endorsement
• latest date by which the national (dow) 2016-08-01
standards conflicting with the
document have to be withdrawn

This document supersedes EN 61938:1997.

EN 61938:2013 includes the following significant technical changes with respect to EN 61938:1997:
– the main title was changed to: Multimedia systems - Guide to the recommended characteristics of
analogue interfaces to achieve interoperability;
– the scope was adapted to the title;
– a new introduction has been added. The necessity of the above revisions is mentioned in this
introduction;
– the values in each table were chosen with respect to the state of the art and representative of best
practice in industry;
– plug-in power systems and soundcard power systems are added;
– a new Subclause 12.3 has been created: Interoperability of portable audio headphones /earphones
and portable audio equipment;
– a new Annex A describing pairing and screening of conductors is added;
– a new Annex B describing phantom power variants for specialized applications is also added.

Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC [and/or CEN] shall not be held responsible for identifying any or all such
patent rights.

Endorsement notice
The text of the International Standard IEC 61938:2013 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards indicated:

IEC 60027 Series NOTE Harmonised as EN 60027 Series (not modified).
IEC 61293:1994 NOTE Harmonised as EN 61293:1994 (not modified).

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SIST EN 61938:2013
- 3 - EN 61938:2013
Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications

The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.

NOTE  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.

Publication Year Title EN/HD Year

IEC 60038 2009 IEC standard voltages EN 60038 2011
(mod)


IEC 60094-2 1994 Magnetic tape sound recording and EN 60094-2 1995
+ corr. March 1995 reproducing systems -
Part 2: Calibration tapes


IEC 60107-6 1989 Recommended methods of measurement HD 567.6 S1 1990
on receivers for television broadcast
transmissions -
Part 6: Measurements under conditions
different from broadcast signal standards


IEC 60130-9 2011 Connectors for frequencies below 3 MHz - EN 60130-9 2011
Part 9: Circular connectors for radio and
associated sound equipment


IEC 60268-1 1985 Sound system equipment - HD 483.1 S2 1989
1)
+ A1 1988 Part 1: General - -

+ A2 1988 - -


IEC 60268-3 2000 Sound system equipment - EN 60268-3 2000
2)
Part 3: Amplifiers + corr. January 2002


IEC 60268-5 2003 Sound system equipment - EN 60268-5 2003
+ A1 2007 Part 5: Loudspeakers + A1 2009


IEC 60268-7 2010 Sound system equipment - EN 60268-7 2011
Part 7: Headphones and earphones


IEC 60268-11 1987 Sound system equipment - HD 483.11 S3 1993
+ A1 1989 Part 11: Application of connectors for the - -
3)
+ A2 1991 interconnection of sound system - -
components


IEC 60268-12 1987 Sound system equipment - EN 60268-12 1995
4)
+ A1 1991 Part 12: Application of connectors for - -

+ A2 1994 broadcast and similar use + A2 1995


IEC 60603-11 1992 Connectors for frequencies below 3 MHz - -
for use with printed boards -
Part 11: Detail specification for concentric
connectors (dimensions for free connectors
and fixed connectors)



1)
HD 483.1 S2 includes A1 to IEC 60268-1.
2)
EN 60268-3 is superseded by EN 60268-3:2013, which is based on IEC 60268-3:2013.
3)
HD 483.11 S3 includes A1 + A2 to IEC 60268-11.
4)
EN 60268-12 includes A1 to IEC 60268-12.

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SIST EN 61938:2013
EN 61938:2013 - 4 -
Publication Year Title EN/HD Year
IEC 60958 Series Digital audio interface EN 60958 Series


ITU-R BT.1700 2005 Characteristics of composite video signals - -
for conventional analogue television systems

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SIST EN 61938:2013



IEC 61938

®


Edition 2.0 2013-06




INTERNATIONAL



STANDARD




NORME



INTERNATIONALE











Multimedia systems – Guide to the recommended characteristics of analogue

interfaces to achieve interoperability




Systèmes multimédia – Guide des caractéristiques recommandées des

interfaces analogiques permettant d'obtenir l'interopérabilité
















INTERNATIONAL

ELECTROTECHNICAL

COMMISSION


COMMISSION

ELECTROTECHNIQUE

PRICE CODE
INTERNATIONALE

CODE PRIX W


ICS 33.160.60; 35.200 ISBN 978-2-83220-836-6



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

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SIST EN 61938:2013
– 2 – 61938 © IEC:2013
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 10
3 Terms and definitions . 10
4 General conditions. 13
5 Power supply . 13
5.1 Alternating current (a.c.) power supply voltages and frequencies . 13
5.2 Direct current (d.c.) power supply voltages . 13
5.3 Power supply feed for microphones . 14
6 Interconnections . 14
6.1 Connections . 14
6.1.1 General . 14
6.1.2 Characteristics of cables . 14
6.2 Connectors . 15
7 Marking and symbols for marking . 16
7.1 Marking . 16
7.2 Symbols for marking . 16
8 Electrical recommended values . 16
8.1 General purpose output/input . 16
8.2 General purpose audio output/input . 16
8.2.1 Audio-only interfaces for consumer equipment . 16
8.2.2 Interfaces for professional equipment and consumer equipment
where audio and video signals are present on the same connector or
cable . 18
8.3 General purpose video input/output . 19
9 Interoperability of microphones and amplifiers . 19
9.1 Microphones (excluding piezoelectric types) . 19
9.2 Power supply feed for electret microphones fed over a signal conductor
(“plug-in power”) . 20
9.3 Power supply feed for electret microphones fed by a separate conductor
(“soundcard power” or “PC power”) . 21
9.4 Phantom supply system . 21
9.4.1 General . 21
9.4.2 Supply voltage polarity . 22
9.4.3 Circuit diagram . 22
9.4.4 Value of the supply voltage . 22
9.4.5 Supply current . 22
9.4.6 Marking . 22
9.5 A-B supply system . 23
9.5.1 General . 23
9.5.2 Output impedance of the microphone . 23
9.5.3 Circuit diagram . 23
9.5.4 Connection of the power supply to earth . 23
9.5.5 Marking . 23
9.6 Polarity of the audio frequency voltage . 23

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SIST EN 61938:2013
61938 © IEC:2013 – 3 –
10 Interoperability of record-playing units (pick-ups) and amplifiers . 26
11 Interoperability of loudspeakers and amplifiers . 26
11.1 Single unit loudspeakers . 26
11.2 Loudspeaker systems . 26
11.2.1 Loudspeakers with built-in amplifier . 26
11.2.2 Impedance-defined loudspeaker systems . 27
11.2.3 Constant voltage loudspeaker systems . 27
11.3 Voltage (or power) interoperability of amplifiers and loudspeakers . 27
11.3.1 Overview . 27
11.3.2 Interoperability requirements . 28
11.4 Polarity of the sound pressure . 28
12 Interoperability of headphones and amplifiers . 28
12.1 General . 28
12.2 Interoperability of headphones with stationary amplifiers . 28
12.3 Interoperability of portable audio headphones/earphones and portable audio
equipment . 29
12.3.1 General . 29
12.3.2 Portable audio headphones/earphones . 29
12.3.3 Portable audio equipment . 29
12.3.4 Recommended values and input/output values for portable audio
headphones/earphones and portable audio equipment . 29
13 Interoperability of amplifiers with other amplifiers . 30
13.1 Pre-amplifiers and power amplifiers for general purpose and sound
reinforcement . 30
13.2 Broadcast and similar line amplifiers . 31
Annex A (informative) Pairing and screening of conductors . 32
Annex B (informative) Phantom power variants for specialized applications . 33
Bibliography . 34

Figure 1 – Audio and video sources and destinations . 9
Figure 2 – Example of plug-in power system for a single microphone . 24
Figure 3 – Example of plug-in power system for a two-channel microphone . 24
Figure 4 – Example of soundcard power system . 24
Figure 5 – Example of phantom power supply system . 25
Figure 6 – Example of A-B power supply system . 25

Table 1 – Direct current (d.c.) power supply voltages and tolerances . 14
Table 2 – General purpose values for audio-only interfaces . 16
Table 3 – General purpose values for audio signals for professional interfaces . 18
Table 4 – General purpose recommended values for video signals . 19
Table 5 – Recommended values for microphones and amplifiers . 20
Table 6 – Required values for phantom supply systems . 25
Table 7 – Required values for A-B power supply systems . 25
Table 8 – Recommended values for analogue record-playing units and amplifiers. 26
Table 9 – Recommended values for impedance-defined loudspeaker systems . 27
Table 10 – Recommended values for constant voltage loudspeaker systems . 27

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SIST EN 61938:2013
– 4 – 61938 © IEC:2013
Table 11 – Recommended values for headphones and amplifiers in stationary
applications . 29
Table 12 – Recommended values for portable audio headphones/earphones and
portable audio equipment . 30
Table 13 – Recommended values for pre-amplifiers and power amplifiers . 31
Table 14 – Recommended values for broadcast and similar line amplifiers . 31

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SIST EN 61938:2013
61938 © IEC:2013 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

MULTIMEDIA SYSTEMS –
GUIDE TO THE RECOMMENDED CHARACTERISTICS
OF ANALOGUE INTERFACES TO ACHIEVE INTEROPERABILITY


FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non-
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
with the International Organization for Standardization (ISO) in accordance with conditions determined by
agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61938 has been prepared by IEC technical committee 100: Audio,
video and multimedia systems and equipment.
This second edition cancels and replaces the first edition published in 1996 and constitutes a
technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
– the main title was changed to: Multimedia systems – Guide to the recommended
characteristics of analogue interfaces to achieve interoperability;
– the scope was adapted to the title;
– a new introduction has been added. The necessity of the above revisions is mentioned in
this introduction;
– the values in each table were chosen with respect to the state of the art and
representative of best practice in industry;

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SIST EN 61938:2013
– 6 – 61938 © IEC:2013
– plug-in power systems and soundcard power systems are added;
– a new subclause12.3 has been created: Interoperability of portable audio headphones /
earphones and portable audio equipment;
– a new Annex A describing pairing and screening of conductors is added;
– a new Annex B describing phantom power variants for specialized applications is also
added.
The text of this standard is based on the following documents:
FDIS Report on voting
100/2130/FDIS 100/2155/RVD

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 publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

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SIST EN 61938:2013
61938 © IEC:2013 – 7 –
INTRODUCTION
The first edition of IEC 61938 was derived from IEC 60268-15, IEC 60574-4 and IEC 60933-1
and also from related proposals which had been submitted up until the date of this revision.
IEC 60268-15 was the first standard to address 'interoperability' – the ability of equipment
from different manufacturers to be assembled into a system with full compatibility at every
'interface'. However, the purpose, terminology and implications of IEC 61938 are now widely
misunderstood because the words 'matching' and 'preferred' used in IEC 61938, are
frequently misinterpreted, resulting in IEC 61938 being regarded as a performance standard,
which was never its intention. The aim of this revision is to make the intention of this standard
easily comprehensible by using widely used terminology in the title and text of the standard.
The features of the revision are the following.
a) Unification and arrangement of existing related standards, including effective proposals
which have been submitted.
b) The concept of "general purpose input/output".
NOTE The standard numbers mentioned above correspond to the revised numbers, if applicable.

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SIST EN 61938:2013
– 8 – 61938 © IEC:2013
MULTIMEDIA SYSTEMS –
GUIDE TO THE RECOMMENDED CHARACTERISTICS
OF ANALOGUE INTERFACES TO ACHIEVE INTEROPERABILITY



1 Scope
This International Standard gives guidance on current practice for the characteristics of
multimedia analogue interfaces to achieve interoperability between equipment from different
manufacturers. It is not a performance standard.
Recommendations for interfaces for equipment used in vehicles, and for analogue video
interfaces for broadcast and similar equipment, are not given.
Refer to IEC 60958 for the interconnection of digital signals.
Figure 1 shows in a diagram the possible interfaces of the audio and video sources and
destinations.

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SIST EN 61938:2013
61938 © IEC:2013 – 9 –


Low Voltage
0 , 5V rated level Power level
or RF level
9.1

Microphone
Pre-
10
amplifier
Record player

High/low sensitivity

12/1 GHz Digital satellite 12.2
Headphones
converter radio tuner

8.2
Active
12/1 GHz Satellite TV tuner
13.1
8.3
loudspeaker
converter Analogue or digital

boxes
8.2
Terrestrial TV tuner
8.3
13.1
Audio power
Analogue or digital

amplifier
Auxiliary
11

8.2
AM/FM radio tuner loudspeaker
boxes
8.3
Video camera or
8.3
camcorder
Video monitor
8.2

Video tape recorder
8.3

8.2
Audio tape cassette
recorder analogue
9.1
Digital audio tape
8.2
Microphone recorder :DAT,DCC,

Minidisc,.
CD writeable recorder

8.2
CD/CD-i/CD-ROM
Laservision player

Auxiliary

Still picture camera
System Printer

Control
bus Personal/home
computer

12.3
Portable audio Portable audio

equipment headphones / earphones

Remote
Equaliser or
Digital sound Digital video processor
control
reverberation unit
processor and memory
emitter
(analogue)

IEC  1298/13

NOTE The numbers indicated above the arrows refer to the appropriate clause or subclauses of this standard.
Figure 1 – Audio and video sources and destinations
Low Voltage sources
Real time signal sources
Peripheral equipment
or pre-recorded signals
Real time signal sources
Radio or TV broadcast
Switchbox/source selector

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SIST EN 61938:2013
– 10 – 61938 © IEC:2013
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60038:2009, IEC standard voltages
IEC 60094-2:1994, Magnetic tape recording and reproducing systems – Part 2: Calibration
tapes
...