Muddle over left/right channel of TRS plug

On 22:08 25 Sep 2009, Rich Grise wrote:


The wikipedia has a useful entry on TRS (tip-ring-sleeve) connectors.
Unfortunately the wiki doesn't explain why the left channel on my adaptors are connected to a RED wire.
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Buy another adaptor from the same source and see if it's the same. Could be your one is simply made incorrectly - or actually sold as a reversal one.
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Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
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Careless assembly. I've seen it in other inexpensive adapters.
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William Sommerwerck wrote:

I'm sure the dealer got a deal on them.
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Jamie wrote:

How would 'the dealer' even know to ask for 'a deal'?
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On 9/25/2009 4:46 AM William Sommerwerck spake thus:

As a mnemonic, I think of it as a political thing (right=red, left=blue [i.e., not-red]).
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On Fri, 25 Sep 2009 09:48:49 -0700, David Nebenzahl wrote:

That's a recent innovation that came with Bush II. Historically, the "Reds" have been the commies. ;-)
Cheers! Rich
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On Fri, 25 Sep 2009 00:19:39 +0100, Peter wrote:

Does it matter? Can you tell "right" from "left" by ear? Lessee, strings on the left, brass on the right, percussion in back...
Of course if it's wrong, just fire up the ol' soldering iron, and swap them. Takes about four minutes.
Cheers! Rich
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On 9/25/2009 2:05 PM Rich Grise spake thus:

As an aside, wonder how many recordings (commercial ones) are out there that have left and right channels reversed. (Obviously not determinable on such material as punk rock.)
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On 22:05 25 Sep 2009, Rich Grise wrote:

Hi Rich. I would love to just resolder them but the pics show the connectors are moulded on to the wires. (That's how we spell "molded" here in the UK.)
It's not for a fixed setup. I'm testing mono microphones but I also need to eliminate disparities in the recorder and player.
Here is are some typical set ups.
--------------------
I use a stereo portable recorder and make a recording with one test mic on one channel and another test mic on the other channel.
To compare the two recordings I might do this. Take the L or R (and I need to identify which is which because that tells me which mic I am listening to) and feed its signal into both L and R conductors on the line-in socket on the PC.
To eliminate disparities created by the recorder (maybe it records differently on its L and its R channel) I need to be able to keep track of the channels when I switch L and R around.
An alternative requirement is when I to feed the portable recorder's output into the PC on both channels (stereo) and then use I would an audio editor to replay either L or R on its own. To avoid colouration from the different L and R replay channels of the PC, I connect the single played channel so that it comes through both speakers. I have to do that by taking the output from the 3.5mm "audio-out" connector which is on only one channel and connect it to be on both L PLUS R on the input of my powered speakers. I use the adaptors I mention for that last step. (In fact it s a bit more comlicted because I also use some one-piece RCA phono couplers to spilt out the two channels.
And there are also other combinations of equipment I use where I need to be sure about L and R.
Phew! Anyway, you can see that mixing up L and R on account strangely coloured connectors is going to add points at which errors in labelling can creep in.
I posted because I was wondering if RED = TIP = R-CHANNEL was part of some convention I had not heard of which may have made sense if only I knew what the convention is.
--------------------
I tried to get around any ambiguity from the above by using these two components together but their prescence just adds unncessary complication because I wire and reqire these combos quite a lot. The extra connectors also add more physical connections which may get be made 100% and can introduce noise to the audio. (3.5mm connectors are prone to this.)
<http://cpc.farnell.com/pro-signal/psg01989/adaptor-3-5mm-s-to-phono - p/dp/AV15537>
<http://cpc.farnell.com/pro-signal/psg02781/adaptor-2x-phono-to-3-5 - jack-st/dp/AV17296>
--------------------
Maybe those connectors with the RED wired to the tip which I got from CPC Farnell are from some incorrectly-wired job lot which they CPC were selling off cheap. See links:
<http://cpc.farnell.com/pro-signal/psg00112/3-5mm-st-plug-to-2x-mono - sockets/dp/AV13710>
<http://cpc.farnell.com/pro-signal/psg00185/lead-3-5mm-s-socket - 2xphono-2m/dp/AV13783>
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On 22:05 25 Sep 2009, Rich Grise wrote:

I'VE REPOSTED MY MESSAGE WITH FEWER TYPOS! IGNORE THE PREVIOUS VERSION.
Hi Rich. I would love to just resolder the adaptors but my pics show the connectors are moulded on to the wires.
Worse still, it's not for a fixed setup because I'm testing mono microphones and need to eliminate disparities in the recorder and player. Below are some typical set ups.
--------------------
I use a stereo portable recorder and make a recording with one test mic on one channel and another mic on the other channel.
To compare the two recordings I might do this: Take the L or R (and I need to identify which is which because of course that tells me which mic I am listening to) and feed its signal into both L and R conductors on the line-in socket on the PC.
To eliminate disparities created by the recorder (maybe it records differently on its L and its R channel) I need to be able to keep track of the channels because I may make another recording with mics swapped around.
An alternative requirement I have is when I to feed the portable recorder's output into the PC on both channels (stereo) and then I would use an audio editor to replay either L or R channel on its own. To avoid colouration from the different L and R replay channels of the PC, I connect the single played channel so that it comes through both PC speakers. I do that by taking the output from one channel of the PC's 3.5mm "audio-out" connector and connect it to both L PLUS R of the input of my powered PC speakers. I would use the adaptors with the colour problem for that last step.
In fact it's just a little bit more involved than that because sometimes I use a one-piece "RCA phono" coupler to spilt out the two channels. I also need some other adaptors as these links show.
<http://cpc.farnell.com/pro-signal/psg01989/adaptor-3-5mm-s-to-phono - p/dp/AV15537>
<http://cpc.farnell.com/pro-signal/psg02781/adaptor-2x-phono-to-3-5 - jack-st/dp/AV17296>
However the presence of all this extra stuff just adds unnecessary complication because I wire and rewire these combos quite a lot. The extra connectors also add more physical connections which may NOT get be made 100% electrically correctly and can introduce noise to the audio. Those 3.5mm connectors are all too prone to this.
There are also other combinations of equipment which need me to be sure about L and R. I might work through these combinations every 5 or 10 minutes depending on the results I am getting.
Phew! You can see that mixing up L and R on account strangely coloured connectors is going to add points at which errors in labelling can creep in.
I posted originally because I was wondering if RED = TIP = R-CHANNEL was part of some convention I had not heard of which may have made sense if only I knew what the convention is.
--------------------
Maybe these connectors I have got are some incorrectly wired rejects which are being sold by CPC Farnell. See links:
<http://cpc.farnell.com/pro-signal/psg00112/3-5mm-st-plug-to-2x-mono - sockets/dp/AV13710>
<http://cpc.farnell.com/pro-signal/psg00185/lead-3-5mm-s-socket - 2xphono-2m/dp/AV13783>
Peter
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On Mon, 28 Sep 2009 10:50:30 +0100, Peter wrote:

When you start your test, tap one mic say, two times, and tap the other mic three or four times. (tap as in, with your fingernail.)
Then see which channel they come out on. :-)
To test the recorder, just use one mic.
Of course, if the outputs are _also_ swapped, then you'd need more experimentation.
Unfortunately, I don't know if there even _is_ a standard for those TRS plugs/jacks.
Good Luck! Rich
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On 20:01 28 Sep 2009, Rich Grise wrote:

Thanks for the info. I wrote that the real problem is the ease and speed of channel identification rather than how to use tapping procedures to determine which channel is which (and which rely on a visual indication of recording levels).
I think the problem was probably due to some duff batches which CPC Farnell were selling off cheaply. I'll check some more of the ones I bought and see if they'll swap them for correct ones. The moral must be not to trust CPC Farnell's quality assurance.
Unfortunately the electronic engineering supplier Farnell UK (not CPC Farnell) also draws from the same stock for these parts and they say this on their website: <<Connectors are an important part of every electronic design and Farnell are committed to bringing you the latest products from the leading Connector manufacturers>>
What a cheek!
http://uk.farnell.com/connectors
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Then put some coloured tape round them - or buy a new one.
--
*Ever stop to think and forget to start again?

Dave Plowman snipped-for-privacy@davenoise.co.uk London SW
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