Mono signal through stereo Headphone Amp

[Shindiggety]

I know this is a lame question, and the answer is probably so simple, but I can't figure it out and I don't want to waste time/money ordering the wrong solutions.

I'm trying to play a mono signal from my Digi 003 output through a stereo headphone amp, but it will only play through the left channel. The signal path starting from Pro Tools is as follows:

Mono Bus -> Mono output -> TRS to XLR -> (XLR Snake) -> XLR to TRS -> Stereo Input on Behringer Micro AMP HA400.

Can anybody suggest an elegant solution to play the mono signal through both channels of the amp?
How would you personally do it? I'm willing to adjust my setup but I'm stuck with the xlr snake and the headphone amp.

Thanks!

 

[mixsit]

I might be missing something, but use a stereo pair output just like if you were going to speakers, then pan the track center.

 

[Shindiggety]

The idea was so that I didn't have to run two channels through the snake.

 

[mjbphotos]

In that last step from the snake, go XLR to TS - no sense in continuing the balanced signal when the headphone amp doesn't have a balance input. Then you might need a TS-TRS(stereo) adapter into the Behr.

 

[ashcat_lt]

You've got two options there.

1) Build a Dual TS>XLR cable - Tip1 to Pin2, Tip2 to Pin3, and both Sleeves to pin1. These come out of both outputs of the interface to your snake. This would be my preferred way of doing it because it's more flexible. It's actually true stereo all the way through, and if you want both channels carrying the same signal ("mono"), you do that in software. I have one of these for each end of an XLR so I can split out to dual TS inputs at the far end, but in your case the headphone amp wants a TRS input, so XLR>TRS cable at that end works fine.

B) Make a single TS>XLR cable where the Tip goes to both Pin2 and 3 and Sleeve to Pin1. I don't like this at all, but it will get it done. You could even hack your current TRS>XLR cable - either leave the Ring disconnected or connect it to the Sleeve.


Edit - Or what mjb said...