Report of the SC-05-02 AES Standards Working Group on Audio Connectors of the SC-05 Subcommittee on Interconnections meeting, held in conjunction with the AES 113th Convention in Los Angeles, CA, US

Chair R. Rayburn convened the meeting.

The agenda was approved with correction of the title of the Working Group and removal of redundant Project X124. The report of the meeting held in conjunction with the AES 112th Convention in Munich, Germany, was approved with addition of comments from J. Woodgate.

Open projects

AES14-R Review of AES14-1992 (r1998) AES standard for professional audio equipment - Application of connectors, part 1, XLR-type polarity and gender
No progress was made.

AES26-R Review of AES26-2001 AES recommended practice for professional audio - Conservation of the polarity of audio signals
No progress was made.

AES45-R Review of AES45-2001 AES standard for single programme connectors - Connectors for loudspeaker-level patch panels
It was noted that figures 1 through 6 need to be rendered in black and white for clarity in viewing and printing. The meeting felt this to be an editorial issue since the original working documents as approved by this Working Group had these figures rendered in black and white. The secretariat has agreed to to update and reprint the published document accordingly.

AES-X11 Fiber-Optic Audio Connections - Connectors and Cables Being Used and Considered for Audio
A meeting of SC-05-02-F was held in conjunction with the AES 113th Convention in Los Angeles, CA, US. A survey of fiber connector usage in professional audio is to be published in AES Journal and was circulated to exhibitors. This will hopefully result in an Information Document. A chart was developed to consider different styles of interconnection cables for possible future work. The possible need for a standard for AES3 over fiber was identified.

AES-X40: TRS Connectors
This document has now been published as AES-R3. AES-R3 needs to have figures 1 and 2 rendered in black and white for clarity in viewing and printing. The meeting felt this to be an editorial issue since the original working documents as approved by this Working Group had these figures rendered in black and white. The secretariat has agreed to to update and reprint the published document accordingly.

AES-X105 Modified XLR-3 Connector for Digital Microphones
This is a development of work in SC-02-02-F on what they called the XLD connector, published as Annex E of AES42-2001. Considerable debate exists within SC-02-02 on the subject of the XLD. In an attempt to clarify why the XLD is desirable, J. Brown wrote a rationale document for SC-02-02. The sole task of SC-05-02 is to define a keying method that will meet the criteria set down in the rationale document. B. Olson will post a preliminary document with a proposed keying method to be considered for feasibility. Completion date was changed to 2003.

AES-X113 Universal Female Phone Jack
J. Woodgate has forwarded a Draft for an Information Document. We are requesting manufacturers of compatible connectors to identify suitable models for inclusion in this information document. Woodgate has one further change to make as a result of evaluating the information and samples sent to him by Switchcraft.

AES-X123 XL Connectors to Improve Electromagnetic Compatibility
The meeting felt that that the Standard simply needed to define the conductive surfaces required on the male XL connector, a circumferential connection to the shielding enclosure of the equipment on the female chassis mounted connector, and some minimum performance values for the mated connectors� circumferential connection RF impedance.

Two surfaces were identified for the male connector. The inside of the shell of the XL from the insulator that holds the pins to the open end of the connector is one surface. On the free male connector the outside of the connector over the same distance is to be the other surface. Both surfaces are to be made of a material suitable to act as a circumferential RF shielding contact. This together with a RF performance specification is sufficient to allow compatibility between connectors from different manufacturers. The details of the female connectors and how the circumferential shielding connection is to be made between mated connectors may vary from manufacturer to manufacturer and from cable to panel mount varieties of the connector. Issues of what connects to this circumferential contact, and in what way, are intentionally being left out of this Standard in order to promote a consensus. Future standards will hopefully address these other issues, but the meeting felt it was important to rapidly develop what was established toward a standard. Brown will lead a task group to write the draft. Neutrik has indicated promising test results from a connector they have prototyped and has agreed to share the results with the working group. Woodgate�s input on the RF impedance issues will be solicited.

AES-X124
This project has been retired.

AES-X130 Category-6 Data Connector in an XL Connector Shell
The secretariat was requested to post a copy of the appropriate IEC specification (developed by IEC group SC48B) to the Working Group document site. Among the issues to be resolved is the correct IEC nomenclature for the 8 position 8 contact data connectors. The AES Standard will be limited in scope to defining those parameters that are critical to allow compatibility of these connectors between manufacturers. Reference will be made to relevant IEC Standards for dimensions of the XL connector shell and dimensions of the data connector that is mounted within the XL shell. In other words we expect to define just the location of the data connector inside the XL shell. W. Bachman of Neutrik will provide us with the relevant dimensions. Completion date is to be changed to 2003.

New projects

There were no new projects.

New business

Several members of the Working Group expressed concern over an XL type connector that was being manufactured where the cable shield connected only to the connector shell and not to pin 1. The reason these connectors were made was to solve specific problems of an end user. It was pointed out that if these connectors were to be applied more generally, then under other circumstances they might well create new problems. It was hoped that such anomalies would be clarified by the publication of the AES-X13 document in due course.

The next meeting is scheduled to be held in conjunction with the AES 114th Convention in Amsterdam, The Netherlands.