SC-02-02 meeting, Online, 2021-05

Report of the meeting of the SC-02-02 Working Group on Digital audio interfaces, held online, 2021-05-12.

Present were Paul Treleaven, Richard Cabot, Anthony Kuzub, Bruce Olson, Al Walker, Junichi Yoshio, Ed Simon, Philip Maness, Gen Ichimura, John Grant

The formal notice on patent policy was read.

The agenda was approved as written.

There were no comments on the report of the previous meeting, held online, 2020-10-05.

Projects assigned to this group but not mentioned here had no action requested or required - see for details.

Open projects:

AES10-R Review of AES10-2008 (r2019): AES Recommended Practice for Digital Audio Engineering - Serial Multichannel Audio Digital Interface (MADI)
The question was raised whether current MADI implementations are compliant with AES10, for instance it originally used AMD TAXI chips and emitter-coupled logic but now most implementations use FPGAs and CMOS logic. A Walker said he was not aware of any incompatibilities; manufacturers' implementations differ but not in a way that affects interoperability. J Meyer pointed out that subclause 6.1 requires timing to be distributed separately, whereas most receivers now recover it from the digital signal. J Grant to propose a revision that recognises that although there is jitter in the arrival time of frames it is now possible to recover a good-quality clock from them.

Other projects
Other projects in the main part of the agenda had been updated to conform to changes in the use of language, and no further changes to them were proposed.

All five parts of AES41, also AES52 and AES-55, are due for revision or reaffirmation in 2022.


J Yoshio reported that new editions of IEC 60958 parts 1 and 3 will be published soon, and part 5 was published in February.

New projects

No new projects were proposed.

New business

No new business was raised.

The next meeting will be scheduled in conjunction with the AES 151st Convention, to be held online in October 2021.

AES - Audio Engineering Society