How to connect a monitor out to a headphone amplifier

D

David.CH

New member
Hello guys,

I'm trying to connect the monitor out of my Behringer X1222 (which is unbalanced) to the input of a Mackie HM-4 Headphone amplifier (which accepts both balanced and unbalanced signals).
I thought that an unbalanced signal would be converted in a balanced signal by the HM4, but it is not the case : i've only got a left signal in my headphones, and it's the same thing with a TS or TRS cable.

I've searched on the internet a cable able to route a signal with a single jack from TS to TRS where the signal from TS would be duplicated on the TRS one, but i did not find one.

The only way that i found is to not entirely plug the TRS cable in the HM4 input, but i don't think it's very clean to do like that.

Does anybody here know a trick to do that ?

For those who ask the question "why not using the phones/ctrl out" it's because on this mixer, muting a channel is only for the mix (which is replicated on the headphones out), the monitor out still route a muted signal.

Thanks for your help.
 
Where do you get the info that the HM-4 accepts unbalanced and balanced 'signals'? The HM-4 input has a TRS jack, but that is for an unbalanced stereo input and the HM-4 does not convert/create a balanced signal. A balanced connection and a stereo connection are two different things.
 
arcaxis said:
Where do you get the info that the HM-4 accepts unbalanced and balanced 'signals'? The HM-4 input has a TRS jack, but that is for an unbalanced stereo input and the HM-4 does not convert/create a balanced signal. A balanced connection and a stereo connection are two different things.
Click to expand...
Yes, OP needs a TS to TRS cable with tip and ring linked. Might be hard to source but easy enough to make if you can solder.

Dave.
 
Many thanks for your help guys.
As arcaxis mentionned it, i made a confusion between balanced and stereo connection.
Mackie documentation is not very clear (for me) and my lack of knowledge put me on error.
Found this tutoriel for the soldering with a 3.5mm stereo jack which is the same if I understood ecc83 explanations.

Once again, many thanks to you all.
 
David.CH said:
Found this tutoriel for the soldering with a 3.5mm stereo jack which is the same if I understood ecc83 explanations.
Click to expand...
That was sort of right. His soldering was a little sloppy. One of those connections looked like it was barely on there, and you don't need quite such big blobs of solder. I'd put some flux on the terminals and wire ends before tinning them. Also, be sure to put the insulator and shells on the cable before soldering the ends.

Important! The wiring would be different for your application. You're not connecting balanced so there's no hot and cold. The mono signal of the Monitor output needs to go to the left and right of the stereo input. So connect black to shield at both ends as shown, then connect red and white to the tip at the TS end, then connect white to tip and red to ring at the TRS end. (You can swap red and white and it won't matter. You can even use a 2-conductor cable, shield and signal, and attach it to tip and ring.)
 
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NO! That is NOT what is wanted! That cable makes a 'balanced' TRS plug into unbalanced.*
The red wire and white should be twisted together and soldered to the tip tag of the TS plug.
Thus, L&R are summed to 'double mono'.

*Bad practice anyway to short ring to screen/ground. Most outputs these days are 'impedance balanced' in which case no harm but no point. In the event the output is a 'proper' symmetrical amplifier output you are shorting the 'cold' amplifier to ground and that can have bad consequences.

Just saw BSG said the same! Sorry, just watched the vid and typed! Worth repeating anyway?
Dave.
 
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