Wiring question for the tech gurus [Answered]

I have need to connect 2 balanced outputs to a single stereo 1/4" for a headphone amp.
 
While I know to take the Hot from each output and connect to Tip/Ring as required and join the grounds together at the sleeve, what do I do with the "cold" from the balanced connections?
 
1) Ground it.
2) Ground it with a resistor.
3) Ignore it and leave it floating.
4) Other.
 
I know I should know this at my age, but it's something I've never needed to do before.
 
Thanks in advance.

Beagle
so basically you tie them to the shields, or ground them.

I don't know how you'd go about grounding the '-' wire as there is no ground.
This is just a cable adapter (but the shield will connect to ground eventually somewhere).
 
So yes, connect '3' (-) and '1' (shield)
 
From :  http://www.raf-net.com/gallery/tools/Wiring%20diagrams.htm
 

 
Yes and no
 
You can't ground the '-' within Karyn's adapter.  You can only connect it to the shield.
Either or both devices connected to it will then ground the shield.
 
I know I'm splitting hairs...
 
But this still doesn't take care of going from 2-balanced to 2-unbalanced.
Probably doesn't matter for a headphone connection.
 
 

Both Beag's and Paul's schematics are the same and are what I will do.  (The balanced outs are actually in a DB25 connector, but that's not important right now).
 
I should have said Screen, of course.  There's no guarantee that the screen is connected internally to ground though it would be unusual if it were not.
 
Thanks guys.

just a quick head's up...
 
connecting the low side (pin 3) to the shield (pin 1) will work most of the time. Exceptions include:

• If the source uses an opamp to drive the low side you can draw excessive current from the source and burn up the opamp.
• If the output uses a cross-coupled topology you can drive the circuit into some nasty distortion when you tie pin 3 to shield.
• If the input circuit suffers from a "pin-1" issue you can reduce the S/N ratio, sometimes significantly, when pin 3 is tied to shield.
• There are also output topologies that will have severe cross-talk when wired pin 3 to shield, but I can't remember what they are, and I doubt you'll run into them in 2015.

The only way to know for certain is to look at the schematic, and sometimes that's more trouble than it is worth. In those cases I start by connecting pin 2 to tip for left, pin 2 to ring for right, and both pin 3s to sleeve. If it is working, and there is no smoke I leave well enough alone. If I have noise problems I then start testing different connections for the shield.
 
These days I use some sort of balancing interface, but that's a tale for another day.

This is for a headphone mix - wouldn't the simple adapter/splitter I use do the trick?  It certainly does for me.
 
Bob Bone
 

I'm reiterating - choose as you wish, of course - all I'm saying is that I spent a ten minute drive and $4.00 to absolutely solve the same issue.  It works.
 
Bob Bone