Report of the meeting of the SC-05-02 Working Group on Audio Connectors of the SC-05 Subcommittee on Interconnections held in Barcelona, Spain 2005-05-27
The meeting was convened by acting chair J. Brown.
The agenda was approved as written. No report for the previous meeting in San Francisco 2004-10-27 was available.
Development projects
AES-X113: Universal female phone jack
A PWD draft has been provided to the Secretariat, who is preparing a formatted version that can be offered for public comment.
AES-X123: XL Connectors to Improve Electromagnetic Compatibility
J. Woodgate had previously agreed to prepare a draft of the document and this was awaited. M. Natter showed samples of cable mounted EMC connectors with integral capacitors and ferrite beads developed in response to work by SC-05-02 and SC-05-05 on AES-X013 and AES-X123.
AES-X130: Data Connector in a XL Connector Shell
An early draft of a proposed standard, prepared by Natter, was discussed. It was agreed that the standard should reference the IEC standard for the "RJ-45" 8-pole modular connector [ISO/IEC 8877:1992 Information Technology - Telecommunications and information exchange between systems - Interface connector and contact assignments for ISDN Basic Access Interface located at reference points S and T , and ISO 603-7:1990 - Connectors for frequencies below 3 MHz for use with printed boards - Part 7: Detailed specification for connectors, 8-way, including fixed and free connectors with common features. ], and that product data sheets should specify the bandwidth of the connector in the terms defined by that standard. There was a general sense that a standard developed under AES-X130 should call for a minimum bandwidth of 100 MHz and encourage greater bandwidth.
Shield termination was discussed in the context of AES48 and project AES-X147 [in SC-05-05]. It was agreed that chassis-mount parts shall conform to AES48, with the RJ-45 shell, if there is one, being the designated shield contact. On free connectors, and on connectors mounted to wiring panels, there shall be no connection to the XL shell. It was noted that shielded cable is widely used in Europe for applications such as Ethernet transmission, but almost never used in North America in that application.
It was noted that dimensions of shells in the draft differ slightly from XL standard, to the extent that they improve shell-to-shell contact. It was agreed that the standard should address mechanical and electrical properties that define how connectors mate, should allow a family of connectors to be manufactured in the same range of mechanical configurations in which XL connectors are currently manufactured, and should be compatible with chassis cutouts for XL connectors. It was agreed that AES-X130 should cover only a chassis socket (female) and cable mounted (free) plug (male).
Natter will incorporate those suggestions in an updated draft, and will post it to the working group reflector. Yonge requested that drawings for publication should in DXF format.
AES-X105: Modified XLR-3 Connector for Digital Audio
Members of the working group who are also members of SC-02-02 reported that an online survey had shown strong (but not unanimous) user support for the scheme outlined in AES-X119, and that language was being prepared by SC-02-02 to modify AES3 to call for use of the connector scheme. With that in mind, SC-05-02 was encouraged to proceed with all speed on AES-X105 to specify connectors to support that scheme. Natter was encouraged to take on that task.
It was noted that visual and tactile means of identifying XLC and XLD connectors were needed as outlined in the current annex to AES42-2001, that is, ridged black and white zebra stripes to identify what was then called the XLD connector. Since AES-X119 calls for three connector types, each must be differentiated from the other. Brown suggested axial stripes for one of the new types and radial stripes for the other. On chassis-mounting parts, the insert might be identified by embossed rings or stripes. In all cases, the markings should be visually and tactilely "bold" so that each can be easily identified both visually and in dark conditions. The existing XL will remain unmarked.
It was emphasized that the scheme approved by users includes both cable mount and chassis mount connectors, as well as XLC and XLD connectors in both genders. Brown felt that the Standard must include all of these variations as outlined in AES-X119 if it is to gain acceptance by both users and manufacturers.
Liaisons
Nothing to report
New projects
No new projects were proposed
New business
There was no new business
The next meeting will be scheduled in conjunction with the AES 119th convention in New York, 2005-10.
