Comments on DRAFT AES59-xxxy

last updated 2012-07-19

Comments to date on DRAFT AES59-xxxy, AES standard for professional audio - Audio application of 25-way D-type connectors in balanced circuits ,
published 2012-06-04 for comment.

The comment period has closed. One comment remains to be resolved.


Comment received from Martin Werwein, 2012-06-05

Using only female connectors for equipment and only male connectors for cabling nevertheless if they are used for inputs or outputs seems to me as a very bad idea.

It counteracts the achievment of XLR connectors over jacks, where lengthening cable pieces can be connected together without the need of gender changers.

Futhermore the likelihood of connecting outputs to outputs is much reduced with different genders for inputs and outputs. It is much more likely to damage an equipment port due to a false connection than due to a mechanical damage of an D-type connector! In decades I've never seen a mechanical damaged D-type connector, neither did our service department. So, this cannot be a serious motivation for using no male connectors within equipment.

Maybe the truth behind this idea is a simplification on the manufacture side at the expense of a more complicated usage at the consumer side. But this should not be the motivation for new standards.

I strongly recommend to define male connectors for outputs and female connectors for inputs, nevertheless if it is an equipment or a cable. Mixed configurations should not be used at all.

(If only four pairs of inputs and four pairs of outputs are necessary, two 25-way connectors should be used, each only half used. Or two 15-way D-type connectors can be used and standardized, one male for the outputs and one female for the inputs.)

Best regards,
Martin Werwein

Reply from Ray A. Rayburn, 2012-06-22

Mr. Werwein,

Thank you for your comments on AES59. You wrote in part:

"Using only female connectors for equipment and only male connectors for cabling nevertheless if they are used for inputs or outputs seems to me as a very bad idea. It couteract the achievment of XLR connectors over jacks, where lenghtening cable pieces can be connected together without the need of gender changers."

The SC-05-02 working group discussed this issue at length and decided on the arrangement shown. As draft AES59-xxxy states in its introduction, "The intent is to simplify the rapid and reliable interconnection of equipment in temporary installations, perhaps using rented equipment, although the method may be extended to permanent installations where appropriate." Mechanical damage to D-type connectors does indeed happen when equipment and cables are being continually packed, transported, and unpacked in non-ideal circumstances.

The principle that the equipment-mounted connectors should be female while the cable-mounted connectors should be male was contained in the initial project draft. In working-group discussion, this arrangement was felt to be generally beneficial in the intended application: the same patch cables could be used at all times; and the more-vulnerable pins of the male connector would all be on an easily-replaceable cable rather than in a piece of rented studio equipment. It was also felt to be important that a combined digital input/output option be available. This arrangement was agreed by the working group for these reasons. The question of extension cables, with male connectors at one end and female connectors at the other (like an XLR cable), was also discussed but the working group decided it did not achieve the objectives of the project as well as the configuration proposed. Instead, a provision for female-to-female adaptors was introduced.

Please note that nothing prevents the use of male to female extension cables if a user decides that has advantages for their operation.

Please reply by the end of the comment period if this reply is not acceptable to you. You may also ask us to consider your comments again for the next revision of the document. You may also appeal our decision to the Standards Secretariat.

Sincerely,
Ray A. Rayburn
Chair AES SC-05 and SC-05-02

Second comment received from Martin Werwein, 2012-06-25

Dear Mr. Rayburn,

I doubt that the statement "The intent is to simplify the rapid and reliable interconnection of equipment in temporary installations, perhaps using rented equipment,..." will be reached by the usage of male/male cables. This draft of the standard will at least not improve the "rapid and reliable interconnection", maybe it will even degrade the existing situation.

You wrote "the same patch cables could be used at all times". This would also be true for female/male cables.

When using male/male cables they may be too short sometimes and have to be lenghtend by female-to-female adaptors. This is very problematic in two ways:

First, common gender changers will not work because of the pin swap they create. So, such adaptors have to be special (may be short) cables in female/female configuration. If common gender changers are used anyhow, very confusing channel swaps will occur. In addition, due to the unbalanced connection in such a case, interferences may appear. I doubt that the reason for that will be easily isolated in a complex installation.

Second, there has to be such adaptors on location at all. Such parts are easily forgotten to pack! With female/male cables there were only ONE type of cable instead of two!

I doupt that machanical damage is such a real problem that it is excuse the need of special adaptors. It is much more likely to have connceting problems due to a missing or wrong adaptor as due to a damaged connector.

Nevertheless I have the feeling, that all decisions are made anyway. If the standard allows different configurations including mixed inputs and outputs at one connector, special adaptor cables will be necessary in many cases. So, this standard will not improve the existing situation. Under these circumstances there should be a definition of the wiring of a 25-way D-type connector only. This would be a slight improvement because the "tascam wiring" would be in some sort offical.

Best regards,
Martin Werwein

Comment received from Christopher Hicks, 2012-06-07

Dear Mark,
Noted with interest. I hope this is adopted widely, as the situation is a shambles at present. I have just one substantive comment.

The draft standard is vague and inconsistent about how connectors should be marked. Section 4.2.2 makes no recommendation or requirement for marking - not even as to whether the connector carries inputs or outputs. Section 4.2.3 however requires that the connector "shall be clearly labelled". This "shall" could be problematic in a situation where labelling is not practical (eg PC expansion card backplates are rarely labelled). Furthermore I wonder whether some slightly more detailed recommendation (not requirement) as to labelling might be an appropriate part of the standard, the aim being to make it clear to the user of a piece of equipment with a DB25F connector on it what to expect from that connector. Something like:

• An 8-way connection used for inputs should be labelled "INPUT" and "AES59"
• An 8-way connection used for outputs should be labelled "OUTPUT" and "AES59"
• A digital combined I/O connection should be labelled "AES3" and "AES59"

This would mean that unlabelled connectors would be technically standards-compliant, but helpful markings such as "MICROPHONE INPUTS 9-16 (AES59)" or "Channels 1-8 (AES3/AES59)" would be recommended.

Best wishes,
Christopher Hicks

Additional comment from Christopher Hicks, 2012-06-19

Dear Mark,
I now realise that comments on drafts are required to make specific proposals as to wording - apologies for this oversight earlier. I think the simplest suggestion I can put to the committee that would satisfy the objective is as follows:

• remove the sentence "Equipment using this alternative shall be clearly labelled." from 4.2.3

• add section 4.2.5 (or 4.4) thus:
"4.2.5 (or 4.4) Labelling
Connectors mounted on equipment and wired according to this standard should be clearly labelled. Any label should include the designation "AES59". Signal assignments shall be described in the accompanying documentation."


I hope this is seen as constructive and helpful; it is certainly meant to be, despite coming quite late in the day, I realise.

Christopher Hicks

Reply from Ray A. Rayburn, 2012-06-22

Mr. Hicks,

Thank you for your comments. I believe you raise some good points with regards labeling, however, changing the Standard at this point would require pulling this version, and delaying publication at least a few months. Since this is the second time we have attempted to pass this Standard, I would hate to retract it at this late date and try a third time to get it passed.

Instead may I propose to amend AES59 shortly after publication to address the labeling issues. That allows us to release this much needed Standard, and still address the valid points you raise with regards labeling.

Please reply by the end of the comment period if this reply is not acceptable to you. You may also ask us to consider your comments again for the next revision of the document. You may also appeal our decision to the Standards Secretariat.

Thanks,

Ray A. Rayburn
Chair SC-05 and SC-05-02

Second comment received from Christopher Hicks, 2012-06-22

Dear Mr Rayburn,

This sounds entirely reasonable. I realise that I made my comments only very late in the process, and I am pleased that you think the points I raised are worthy of serious consideration.

Regards,
Christopher Hicks

Comment received from M. Ikeda & T. Holton, Yamaha, 2012-07-13

Dear Sirs,

Yamaha would like to address comments on "DRAFT AES standard for professional audio - Audio application of 25-way D-type connectors in balanced circuits".

Yamaha does not believe that the proposed AES59 standard will be sufficiently beneficial to the Pro Audio industry in its current form. At Yamaha, we have a very substantial number of products already actively being used in the market which do not adhere to the proposed standard. The pin-out specification currently used on Yamaha products was first introduced to the market in 1995. In total, there are over 60,000 Yamaha products in the market utilizing this specification, amounting to over 100,000 DB25 connectors. In addition, there are a large number of products from other manufacturers that also adhere to this same specification.

It would not be practical or reasonable for Yamaha to change our specification for future products to match the proposed AES59 specification. This would cause very significant confusion and inconvenience for our customers. As a result, this proposed new standard will not solve the incompatibility issues that currently exist. Consequently, Yamaha objects to this standard being ratified and strongly requests that it should be reconsidered.

If it is considered necessary to establish an AES standard in relation to this issue, Yamaha's recommendation would be for the standard to identify two alternative pin-out specifications (e.g. Type A and Type B). Assuming that most manufacturers would adhere to one of these types or the other, it could become relatively simple for end users to understand the specification of a particular product. Products could be clearly identified as adhering to either AES59 Type A or AES59 Type B.

If the AES is interested in considered this sort of approach, Yamaha will be glad to participate in any further standardization process to achieve a standard that meets the industry's practical requirements.

Very truly yours,
Masahiro Ikeda, Terry Holton
Yamaha, London R&D Centre

Reply from Ray A. Rayburn, 2012-07-18

Dear Ikeda-san,

Thank you for your comments on AES59-xxxxy, published in a formal public Call for Comment on 2012-06-04.

It is my opinion as Chair of the working group that developed this Standard that it is useful to the professional audio community as it stands, and it straightforwardly allows connections to comply with AES48-2005, "AES standard on interconnections - Grounding and EMC practices - Shields of connectors in audio equipment containing active circuitry". Therefore the AES should move forward and publish this Standard without revision at this time.

This does not mean that the Standard can't be improved. If Yamaha wishes to participate in the SC-05-02 Working Group and suggest we revise this Standard, I would welcome your participation and input.

Your suggestion of having two alternative pinouts called Type A and Type B sounds like a workable solution.

I would like to point out that although AES rules require we revisit every Standard at 5 year intervals, that does not mean we can't revise a Standard at any time it seems beneficial.

Conformance with AES Standards is completely voluntary. AES Standards do not suggest or require changes in current products, and likewise the design of future products is made by their respective manufacturers.

The comment period has ended, so if this reply is not acceptable to you I ask that you reply within a week. You may also ask us to consider your comments again for the next revision of the document. You may also appeal our decision to the Standards Secretariat.

Sincerely,
Ray A. Rayburn
Chair SC-05 and SC-05-02

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