Muddle over left/right channel of TRS plug

[Peter]

I have a 3.5mm TRS plug which is prewired. It looks like this

http://www.mycablemart.com/store/images/products/1085_large.jpg

The tip of that TRS plug is connected to the red wire (RIGHT
channel).

Has that been done correctly? I thought the tip of the TRS plug is
the LEFT channel.

(I also have a 3.5mm TRS socket which is prewired and the red wire is
also the tip.)

 

[William Sommerwerck]

Nope. Tip is left. It has been for 50 years.

 

[Jon Slaughter]

I have a 3.5mm TRS plug which is prewired. It looks like this

http://www.mycablemart.com/store/images/products/1085_large.jpg

The tip of that TRS plug is connected to the red wire (RIGHT
channel).

Has that been done correctly? I thought the tip of the TRS plug is
the LEFT channel.

(I also have a 3.5mm TRS socket which is prewired and the red wire is
also the tip.)

Does it matter? If it's backwards then just reverse the RCA's?

 

[William Sommerwerck]

As to colours, in the UK some pro stuff uses red and green

as per the naval convention - ie red (port) left, green (starboard)
right. Whereas in domestic stuff red is usually right. Just to add
to the confusion.

As far as the RCA plugs are concerned, the Red plug has long been Right.

 

[William Sommerwerck]

Nope. Tip is left. It has been for 50 years.

I happen to like my tips on the right.

Why do I feel I'm sitting under the caterpillar's mushroom?

 

[David Nebenzahl]

As far as the RCA plugs are concerned, the Red plug has long been Right.

As a mnemonic, I think of it as a political thing (right=red, left=blue
[i.e., not-red]).

 

[Rich Grise]

I have a 3.5mm TRS plug which is prewired. It looks like this

http://www.mycablemart.com/store/images/products/1085_large.jpg

The tip of that TRS plug is connected to the red wire (RIGHT
channel).

Has that been done correctly? I thought the tip of the TRS plug is
the LEFT channel.

(I also have a 3.5mm TRS socket which is prewired and the red wire is
also the tip.)

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

 

[Rich Grise]

As far as the RCA plugs are concerned, the Red plug has long been Right.

As a mnemonic, I think of it as a political thing (right=red, left=blue
[i.e., not-red]).

That's a recent innovation that came with Bush II. Historically, the "Reds"
have been the commies. ;-)

Cheers!
Rich

 

[Rich Grise]

Pro gear doesn't use RCA plugs. But can use TRS.

Is "TRS" a mnemonic for something? All I can think of when I see it is
the Radio Shack/Tandy TRS-80, pronounced "Trash 80". ;-)

Thanks,
Rich

 

[Rich Grise]

Why do I feel I'm sitting under the caterpillar's mushroom?

Good drugs? %-}

Cheers!
Rich

 

[Rich Grise]

Tip ring sleeve. Unbalanced stereo or balanced mono. Or sometimes a mono
in and out on a mixer.

I'd guess originally designed for telephone exchanges. In the UK, the
telephone one is known as a type 316 and has a smaller tip than stereo
jack plugs. And is still in use - must have been designed over 100 years
ago. Dunno if the US one is the same.

Oh, yes - the US has been using "Tip & Ring" for about as long as there
have been telephone exchanges. (a hundred years?)

My cousin Owen inherited Uncle Dick's farm - they still have a
wall-mounted crank-style phone with the separate earpiece similar to this:
http://youngandthewireless.com/emptying-nests/wp-content/uploads/2009/05/old_telephone.jpg
[mind the wrap]
and they have an early phone book - most of the phone numbers were two
digits! (Circuit & phone). (it wasn't a very big town. ;-)

If you're curious, it's Lake Crystal, MN.

Cheers!
Rich

 

[William Sommerwerck]

"jack plug" seems to be a British usage -- elsewhere it is an

Seems strange to me as 'Jack' is a common name denoting
male. Jack rabbit, jack tar, etc. Wonder what the root is in this
case?

Believe it or not, the OED2 doesn't list this usage.

Many years ago, when I worked for Bendix Field Engineering, I became
acquainted with what was known as a "jackscrew" connector. There were male
and female versions, so I suggested to the manufacturer that they be
rechristened "johnscrew" and "janescrew" connectors. They had no idea what I
was talking about.

 

[David Nebenzahl]

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.

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.)

 

[Peter]

Is "TRS" a mnemonic for something? All I can think of when I see
it is the Radio Shack/Tandy TRS-80, pronounced "Trash 80". ;-)

Thanks,
Rich

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.

 

[Peter]

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

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>

 

[Peter]

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

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

 

[William Sommerwerck]

Unfortunately the wiki doesn't explain why the left channel

on my adaptors is connected to a RED wire.

Careless assembly. I've seen it in other inexpensive adapters.

 

[Jamie]

Careless assembly. I've seen it in other inexpensive adapters.

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

 

[Rich Grise]

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.

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

 

[Peter]

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

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