16.4.2 aux out - only getting sound in left ear Need help ASAP please!

I've just gotten Rolls PM55 headphone amps I need for a big rehearsal tonight.

But when I run a TRS cable from the mixer's aux out into the Rolls I only get sound in my left ear. Doesn't seem to help if I link the aux channels or not. Try panning away from left ear and I only get silence.

Tried it with guitar di'ed and with a mic, so I know it's between the mixer input and my ears.

The Rolls is supposed to be Stereo. I know I'm overlooking something or doing something stupid.

Please help out an ignoramus.

The Aux outs are mono. It's a TS jack you need.

Normal procedure for stereo Aux outs is to link, say, Aux1 and Aux2, and use a pair of mono jacks to the stereo ins of your headphone amp. When linked, the faders for Aux1 and Aux2 control level for each, but with the rotary sends, Aux1 encoders control the level to both Aux1 and 2, and Aux2 encoders control the pan/spread.

ajrussellaudio wrote:The Aux outs are mono. It's a TS jack you need.

Normal procedure for stereo Aux outs is to link, say, Aux1 and Aux2, and use a pair of mono jacks to the stereo ins of your headphone amp. When linked, the faders for Aux1 and Aux2 control level for each, but with the rotary sends, Aux1 encoders control the level to both Aux1 and 2, and Aux2 encoders control the pan/spread.

So I need a Y-cable I assume? I only have one input on the Rolls which is in stereo.

I don't know the Rolls but I googled it. Says here the input is mono/stereo, in which case a standard mono jack cable (guitar lead etc) would do it.

If you need stereo monitoring, then yeah, a Y-cable is the way to go.

I don't mean this to sound cheeky, but I never understood why a musician might need stereo monitoring. So help me out here, what are you playing that you need a stereo feed for?

Agree about the fact that monitoring in mono will do the job. Soooooo, I have this little 1/4 TRS (female) to TS (male) adaptor that I use. Essentially it allows me to take the output of a single aux out and it sends the sound to both sides of the earphones. Awsome, I now have more aux outs available for additional monitor mixes.

ajrussellaudio wrote:I don't know the Rolls but I googled it. Says here the input is mono/stereo, in which case a standard mono jack cable (guitar lead etc) would do it.

If you need stereo monitoring, then yeah, a Y-cable is the way to go.

I don't mean this to sound cheeky, but I never understood why a musician might need stereo monitoring. So help me out here, what are you playing that you need a stereo feed for?

I got it solved. Y-cable with two mono outs from the SL through a single 1/4" plug into the Rolls.

I don't need stereo. But the SL has the capability and there's only three of us in our band, so why not? Sounds great and adds more "space" in your ears. I'm also using a stereo delay.

pater familias wrote:
So I need a Y-cable I assume? I only have one input on the Rolls which is in stereo.

A Y cable won't do you any good. What you need is a mono-to-stereo adapter that has a TRS output with the tip and ring tied together, and a TS input connected to that tip-ring output.

Go to your friendly local Radio Shack store and get a Catalog #: 274-1520. That'll fix you up for only $3.

It's been my experience that stereo in ears just sound more natural. After all, that's how we listen with our ears isn't it?

ajrussellaudio wrote:
I don't mean this to sound cheeky, but I never understood why a musician might need stereo monitoring. So help me out here, what are you playing that you need a stereo feed for?

It's one of those things that we're doing more of today because we can. Musicians have worked for years with mono headphone mixes but some are more comfortable with stereo mixes.

The condescending answer is that in the old days, we didn't have off-the-shelf headphone amplifiers. We used an ordinary mono or stereo amplifier and built (you couldn't buy one) headphone junction boxes that had a mono input to a stereo jack so both phones got the same signal. Today most people who are recording don't have the knowledge, tools, or imagination to do that, so they want a place to plug in their headphones that just works.

Some headphone amplifiers have a mono input, usually along with a stereo input. Some don't.

I'm seeing questions like this more and more often these days. Maybe I should write an article about the care and feeding of headphone amplifiers.

MikeRivers wrote:

pater familias wrote:
So I need a Y-cable I assume? I only have one input on the Rolls which is in stereo.

A Y cable won't do you any good. What you need is a mono-to-stereo adapter that has a TRS output with the tip and ring tied together, and a TS input connected to that tip-ring output.

Go to your friendly local Radio Shack store and get a Catalog #: 274-1520. That'll fix you up for only $3.

Sorry to disagree, but I used a Y-cable last night and it worked flawlessly.

I was under the mistaken assumption that when you link Auxes into stereo pairs one of the Aux outs serves as a stereo out for just running one cable to your headphone amp or IEM trans.

pater familias wrote:

MikeRivers wrote:

pater familias wrote:
So I need a Y-cable I assume? I only have one input on the Rolls which is in stereo.

A Y cable won't do you any good. What you need is a mono-to-stereo adapter that has a TRS output with the tip and ring tied together, and a TS input connected to that tip-ring output. ]

Sorry to disagree, but I used a Y-cable last night and it worked flawlessly.

Mike's idea would have gone the other way. It would have given you a mono mix out of one Aux, but in both ears. Whatever works for you.

I guess I'm just old fashioned when it comes to monitoring. Most of the venues I work at have floor wedges, and most of the bands are indie rock types who would laugh in my face if I offered them IEMs. So my monitor mixes will be mono for the foreseeable future. At my level in the industry, monitors are just for hearing yourself, not for anything fancy like stereo mixes.

pater familias wrote:
Sorry to disagree, but I used a Y-cable last night and it worked flawlessly.

Sorry, some people just like to be disagreeable.

What kind of Y cable did you use and how did you use it? From your explanation, it sounds like you used two aux outputs and an "Insert" Y cable - two TS plugs to one TRS plug. That's indeed the right way to send a stereo headphone mix to your headphone amplifier, but I thought you were trying to send a mono mix to it.

When I think of a Y cable, I think of all three branches connected in parallel. Man, I really need to do that cable workshop at the next PreSonusphere!

I was under the mistaken assumption that when you link Auxes into stereo pairs one of the Aux outs serves as a stereo out for just running one cable to your headphone amp or IEM trans.

Nope. Linking them means that instead of having two level controls on the adjacent pair of channels, one of them controls the level of both outputs and the other controls the balance, or pan, between them. It probably also links the Fat Channel processing so that both channels get the same processing.

When you use the channels linked, instead of having six auxiliary outputs that you could use for six mono headphone mixes, you have three stereo headphone mixes. If that's all you need, fine.

Ok Mike clear this up for me please!!!!! My snake only has XLR. So I purchased some TRS connectors to replace the XLR's so I can get into the Aux outs on the SL. I want to go Aux out TRS Thru the snake then come out of the snake into the headphone amp. I want MONO ONLY. I thought this would keep the signal balanced there for reducing any noise that may try to enter the signal path. I will also make some TRS to XLR cables that go from the snake to the headphone amp. Am I supposed to tie the tip and ring together or just solder it up balanced? I.E. pretending that the TRS is just an XLR connector. I have read conflicting things on here and I want to solder once if I can!

Thanks for any info!!!!!

We are using unbalanced cords at the moment with NO noise issues but I always want it done correct if I can.

Billyp07 wrote:Ok Mike clear this up for me please!!!!! My snake only has XLR. So I purchased some TRS connectors to replace the XLR's so I can get into the Aux outs on the SL. I want to go Aux out TRS Thru the snake then come out of the snake into the headphone amp. I want MONO ONLY. I thought this would keep the signal balanced there for reducing any noise that may try to enter the signal path. I will also make some TRS to XLR cables that go from the snake to the headphone amp. Am I supposed to tie the tip and ring together or just solder it up balanced? I.E. pretending that the TRS is just an XLR connector. I have read conflicting things on here and I want to solder once if I can! Thanks for any info!!!!!

We are using unbalanced cords at the moment with NO noise issues but I always want it done correct if I can.

I'm not Mike, but maybe i can help...

I think you are asking to go from TRS mono balanced to TRS binaural (same signal in both sides of a stereo device).
If so then wire it up like this: mono balanced TIP to binaural TIP & RING, mono balanced RING & SLEEVE to binaural SLEEVE.
This connects the + signal from the mono unbalanced side to both the right and left stereo inputs. It grounds the - signal to ground, effectively unbalancing the output signal.
WARNING: Clearly label this cable, as it is non-standard and can damage outputs of some devices if the binaural connector end is plugged into a tube amp output, for example.

The only other time I have ever heard of a tip-ring connection is making a cable to steal an output signal from an insert jack.
TRS -TS cable. Plug the TRS into the insert jack and the TS end is an unbalanced output of that channel at the point of insert.
WARNING: this is not a best practice, and if you make a cable like this, label it clearly. This cable is dangerous to many types of outputs and may cause the unsuspecting to damage a device or cut the cable believing it to be defective.

Billyp07 wrote:My snake only has XLR. So I purchased some TRS connectors to replace the XLR's so I can get into the Aux outs on the SL. I want to go Aux out TRS Thru the snake then come out of the snake into the headphone amp. I want MONO ONLY. I thought this would keep the signal balanced there for reducing any noise that may try to enter the signal path.

It takes two to tango. In order to take advantage of the common mode noise rejection of a balanced interconnection, the source needs to be balanced (which it is) and the destination needs to have a differential input (which is usually misnamed a "balanced input" - I won't fight that battle).

I will also make some TRS to XLR cables that go from the snake to the headphone amp. Am I supposed to tie the tip and ring together or just solder it up balanced? I.E. pretending that the TRS is just an XLR connector.

On the mixer end (I know what this is), treat the TRS jack the same as an XLR connector. Tip to pin 2, ring to pin 3, sleeve (shield) to Pin 1. On the headphone amplifier end, it depends on how that jack is wired. If it's a stereo jack like what we've been discussing here, you're not going to have a balanced connection because it's two single-ended inputs, not one differential input. If that's what you have, the best way to make the connection at the headphone amplifier end is to tie the tip and ring terminals of the TRS plug together, and connect that to the tip (pin 2) wire coming from the XLR. This will get the mono signal out of the mixer to both the left and right inputs of the headphone amplifier. To complete the signal path, solder both the shield and ring wires the sleeve of the plug going into the headphone amplifier. If you're making adapter cables, be sure to mark which one is which.

By keeping the run balanced through the length of the snake, you have the option of disconnecting the shield at the headphone amplifier end if you have a problem with hum. It might reduce it. It depends on why you have the hum. But that's a topic for a workshop at the next PreSonuSphere.

We are using unbalanced cords at the moment with NO noise issues but I always want it done correct if I can.

Well, if you're feeding the headphone amplifier from an unbalanced (TS) plug, then it's probably a real mono input, not a stereo input. If it's a differential input (probably called "balanced") then wire the adapters XLR 1-2-3 to S-T-R on both ends and you'll have a fully balanced interconnection.

Gotta have all the information in order to make the right recommendation. So now you have it both ways. ')