3 Pin XLR headphone plug - wiring pin out

XLR plugs for headphone use are typically wired the same as interconnects, with the ground connection left unconnected at the headphone end. If you want to ground a shielded headphone cable, use the shell of the plug as pin 1 is not always grounded in the amp.

XLR Pin 3 (equals TRS stereo jack Tip) is Left channel, Pin 2 (TRS Ring) is Right channel and Pin 1 (TRS Sleeve) = signal ground. I like Nikongod's explanation about not connecting cable shield at input to signal ground but is every audio equipment producer reading this? :-)

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het.s

The OP's question is confusing, at least to me.  Around here, when one speaks of using 3-pin XLR's for headphone plugs they generally mean 2.  One plug for Left, one for Right, with the desired result being able to plug those headphones into a "balanced" headphone amp.  I'm going to assume that this is what was the question that was intended to be asked and elaborate on Nikongod's answer, which is that the general audio standard is:

(table courtesy of wikipedia)

which for us would mean connecting the in-phase to pin 2, out-of-phase to pin 3 and leaving pin 1 unconnected.

Now if the OP intended to use a single 3-pin XLR as a headphone plug they are certainly welcome to do so and I can think of some good reasons to do it (avoids the whole shorting problem for one thing) but as far as I am aware there is no industry standard for doing so nor is there any commercially produced product that does so.  That's not to say that there isn't, I just haven't seen it.
 

Quote:

Originally Posted by het.s 

XLR Pin 3 (equals TRS stereo jack Tip) is Left channel, Pin 2 (TRS Ring) is Right channel and Pin 1 (TRS Sleeve) = signal ground. I like Nikongod's explanation about not connecting cable shield at input to signal ground but is every audio equipment producer reading this? :-)

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het.s

Why not use a standard 1/4" TRS, it looks like it's combo jack.

My post a few posts above assumed this was for a balanced headphone output. Thats what you get when you assume!

Linn used to use a single 3pin XLR for both channels on their tonearms. Ironically 5-pin din plugs were very well standardized before this.
 

Quote:

Originally Posted by grokit 

Why not use a standard 1/4" TRS, it looks like it's combo jack.

XLR's dont short when you plug and unplug.

[joke] it is also common knowledge that systems that use XLR connectors are inherently superior to systems using "not XLR" (I go wash my mouth out with whisky) plugs.[/joke]

The Neutrik combo-jacks have my personal favorite 1/4" in&out feel. nothing else has the same combination of smoothness but still good tactile feel.  

As I said before, I haven't seen everything.   As far as what pinout to use, who knows unless it's in the manual.  There's no standard for single-ended XLR headphone outputs.  It might be wired the same as het.s said but I wouldn't chance it, I'd just use a 1/4" plug.

The pinout to connect stereo using single 3pin XLR (I do use single XLR for single-ended stereo signal) is taken from neutrik combo connector, where pin 1 = S, 2 = R and 3 = T. So when there's no standard it is good idea to follow this setup (as pins are hardwired inside neutrik combo connector so you can plug XLR or TRS without soldering iron :-)

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het.s

 You don't need to put a 3-pin XLR plug on your headphones for the Yamamoto, just plug them into the jack as you would any other headphone amp.

Quote:

Originally Posted by het.s 

So when there's no standard it is good idea to follow this setup (as pins are hardwired inside neutrik combo connector so you can plug XLR or TRS without soldering iron :-)

 

The pins in Neutrik combo jacks are not hard wired: the builder is free to do anything with any of them independently of the others.

When there is no standard the best practice is to take the time to figure out exactly what you are dealing with. 

Quote:

Originally Posted by nikongod 

 

The pins in Neutrik combo jacks are not hard wired: the builder is free to do anything with any of them independently of the others.

 

When there is no standard the best practice is to take the time to figure out exactly what you are dealing with. 

Oops, sorry about wrong info about combo connectors. By the way, combo connector (NCJ6FI-S) has gold plated XLR contacts, TRS contacts are not gold plated (at least solder end).

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het.s