Stereo trs to mono xlr for monitoring...

[Shellacattack]

I recently purchased one Behritone C50a to use as a mono/auratone check on my mixes. I'm running a 1/4" trs out of a Presonus HP4 headphone jack, into the xlr on the Behritone. When fully plugged in, I'm not getting both channels equally.... so I pull out the 1/4" trs so it's at the halfway point (what's the term for this?), and it seems like I'm getting everything, but it's a little tough to tell because of the frequency response of the Behritone.

It seems that the 1/4" trs is kind of touch and go at that midway point, so I'm wondering if there's another approach I should go with. A different cable perhaps, or maybe I'm thinking about this all wrong, and it won't work to connect the stereo out of the headphone jack to the Behritone.

Any help is much appreciated!

[Nate Dort]

A headphone jack is a stereo signal, and the XLR is mono balanced, so it's going to sound really strange, i.e. one side out of polarity.

At the bare minimum, you need to send the tip and ring to pin 2 of the XLR, sleeve to pin 1. That may not sum properly due to the output impedance of the headphone amp though.

A better option would be to sum the tip and ring through a couple of isolation resistors (10k would work fine) to pin 2. Sleeve to pin 1.

The best option would be to use actual line-level outputs, sum them in a mixer, and send an actual mono balanced signal to the speaker. Alternatively, sum the signals in your DAW (if that's what you're using) and send it out single line-level output.

[philbo]

The right way to do it:
"Y" together the two channels through two 100 ohm resistors (this way the two channel outputs aren't directly shorted together). I suspect 10K might be a bit too high for a value.

Like this:
TRS stereo ouput 1/4" mono plug
T--100ohms-\
...................|--------T
R--100ohms-/
S------------------------S

(The periods are there so the picture posts correctly)

Then use a balun (direct box) to translate the unbalanced mono signal to balanced XLR.

[Nate Dort]

Yeah, you're right. Headphone output should use lower value resistors. 100 ohm would work fine. Though the added attenuation from a slightly higher value might be welcome in this situation. Headphone signals going into line-level inputs are usually way too hot.

[JLiRD808]

Im doing this right now too...want to go from a headphone out on an HP4 to a Behritone, except I was just gonna go to the 1/4" input.

Wouldn't I want to use a stereo TRS and then make the other end mono, as well as add the resistors?

Also, I bought 100ohm resistors today, however, I wasnt expecting the options of 1/4watt, 1/2 watt, and whole watt . Does it even matter?

Thanks!