Mixer Headphone Output to Headphone Amp

M

mactreouser

New member
Hi,
I'm setting up the recording monitoring system for vocal recording. I'm sending the signal from the headphone output to 4 inputs Headphone Amp.

Question:
1) Is the patch above Ok?

2) No matter how I Balancing the volume between Mixer Headphone Output and the 4 inputs Headphone Amp to get the louder signal, it just "Distortion". What's wrong?

Thanks!
 
Behringer UFX1204 via USB, Behringer HA400, Balanced 1/4 inch both end. LPX on MacBook.

Your suggestion is appreciated!
 
mactreouser said:
2) No matter how I Balancing the volume between Mixer Headphone Output and the 4 inputs Headphone Amp to get the louder signal, it just "Distortion". What's wrong?
Click to expand...

Hi,
test your setup with some commercial audio tracks or a reliable source first. (youtube, spotify, iTunes, whatever).
That way you rule out the possibility that your input signal is too hot.

If those sources check out fine, you need to lower the gain on, or remove processing from, your input signal.
 
bouldersoundguy said:
Are you recording vocals over prerecorded instrumental tracks?
Click to expand...
Sometimes yes, sometimes just a voice over recording.

Steenamaroo said:
Hi,
test your setup with some commercial audio tracks or a reliable source first. (youtube, spotify, iTunes, whatever).
That way you rule out the possibility that your input signal is too hot.

If those sources check out fine, you need to lower the gain on, or remove processing from, your input signal.
Click to expand...
Will check that out soon. In fact, there is no issue when I just plug the headphone on Mixer, no Matter how loud I turned it up, it just fine. Headphone from mixer to a headphone amp, is this gonna be not working to get the right result? It just like linking an AMP to another AMP?!
 
Just gave it a drive. Indeed, distorted no matter source from YouTube or other platforms!

Still, when I output from the Control Room (LR), it was perfectly OK!
 
It is not unheard of to drive the headphone amp from the mixer control room outputs. They would give levels that match the headphone amp's input (which is why it is 'perfectly ok').

If you don't need all four headphone outputs, you can use one to go to your speakers.
 
It could be a faulty headphone amp. You're using the power supply that came with it?

It's definitely worth trying on the control room output instead of the headphone output, though I would assume by the stereo TRS input it's meant to be compatible with headphone outputs on mixers etc. And if headphones into the mixer work but the amp is distorted I'm leaning toward something being wrong with the HA.
 
I've got a Behringer X1204USB and a HA400. Just hooked it up to a line out of my PC to the stereo ins 5/6 of the mixer and gave it some signal from an mp3. After setting a couple switches and levels I got clean audio in the headphones from the HA-400. I think it may be a bit different than your mixer as far as the output circuitry for the headphones. I have a service manual for the the UB1204FX and it uses an OP Amp to buffer the signal from the parallel control room outs, but possibly with out normal loading from the headphones maybe could develop a signal voltage that could overdrive the headphone amp.

However something that did mess with my head for a while (but probably not related).....
The combination of the line out on the computer into the stereo line ins of the 1204 does something a little odd and does exhibit some distortion for a given setting of the +4/-10 level button and it's not because of signal level. The line inputs of the 1204 are direct coupled and will pass DC voltage to the OP Amp in the front end. My computers line out jack for what ever reason has a DC bias voltage on it (I think it has something to do with the computer soundcard sensing what gets plugged in). This DC from the computer finds its way to the mixer and being direct coupled gives the OP Amp a DC offset from zero, offsetting the signal peaks to have less headroom and causes a distortion of the audio. The occurs when the -10 is enabled with the switch, but not with +4 which appears to lessen the effect of the DC offset by altering the OP Amp gain and headroom.
 

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Are you suspect the issue came from the "power" from the adapter? Which means gonna run it without power supply? It that possible? Will give it a try soon!
 
mactreouser said:
Are you suspect the issue came from the "power" from the adapter? Which means gonna run it without power supply? It that possible? Will give it a try soon!
Click to expand...

I suspect the unit is faulty, but the wrong power supply could make it behave like it's faulty. It won't work at all without the power supply.
 
Mac, I appreciate that English is not your first language and I applaud your efforts but from your comments so far I have, with the greatest respect, reached the conclusion that you don't have the faintest idea how even basic electrical systems work.

Now, this does not matter if someone is buying a stock recording setup "off the shelf" say, mics, AI, headphones and cables, maybe monitors. The gear all comes with instructions and "does what it does" as it were.

But you want to go beyond that and setup special systems. Fine IF you have the electronics smarts to sort the issues that arise but you and your friends plainly don't....The "power" issue for example? The Berry headphone amplifier came with its correct supply or it didn't. Now a HP amp should not be THAT fussy about the supply but YOU need to know the volts and milliamps such a supply should be rated at. Do you for instance own a digital multimeter?

The point about a DC offset seems feasible? (anyone who leave an input DC coupled should be shot IMHO!).

We will help you all we can but you must be systematic.

Dave.
 
mactreouser said:
Oh? So how do I check to ensure the faulty issues?
Click to expand...

The first thing is to ensure it's the right supply. If it's the one that came with the amp you can assume it's right.

By connecting headphones straight to your mixer you determined that all is good up to that point.

Next try the amp with a different source, like a home audio system. If the amp is distorted but headphones straight into the system sound good then the evidence is getting strong.

Finally, try another headphone amp on the same sources. If it sounds okay then it's pretty certain something is wrong with yours. Of course you may not have another headphone amp to try, but that's the procedure.
 
If haven't tried yet, start with the headphones volume on the mixer at zero, HA-400 output Level at about 12 o'clock, and slowly increase the headphones control on the mixer.

I'm sort of the belief it may be an issue with the HA-400 not loading the headphones output enough to keep the signal level down. The mixer headphone output OP Amp is operating off +/-15vdc and the resistor on the output of the headphones jack is 47 ohms. The signal swing could conceivably reach close to 15v peaks with the 100k ohm load of the HA-400, which may overload its frontend. The manual for the HA-400 seems to mention its input as being a "Line" source, rather than from a headphones jack.
 

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Sorry Mark but that does not compute! The output of the HP opamp will be almost perfectly regulated and not need loading. In any even a load of 47 Ohms would be needed to produce just a 6dB drop..IN THEORY! The op amp's output would collapse for a load less than several hundred Ohms if a "decent" chip such as one of the NE55xxx family and if a TL0XXX it would cope with only a few k Ohms.

Dave.
 
X1204USB mixer (may be a bit different than the the OP's mixer, but similar)

- Set headphone output to 2.00 vrms (about 10 o'clock on control) no load
- Loaded the headphone output with 100k ohms (approx. HA-400) > 2.0 vrms measured
- Loaded the headphone output with 33 ohms (approx. most headphones)> 1.15 vrms measured

Yes, at the OP Amp the output would likely be relatively constant/"regulated", but the resistor in line from the output of the OP Amp to the headphone jack causes a drop, thus the variance of output for external loads. Kinda just hinting at the OP may be not turning down the output of the headphones on the mixer to accommodate the change in output from different loading.
 
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arcaxis said:
X1204USB mixer (may be a bit different than the the OP's mixer, but similar)

- Set headphone output to 2.00 vrms (about 10 o'clock on control) no load
- Loaded the headphone output with 100k ohms (approx. HA-400) > 2.0 vrms measured
- Loaded the headphone output with 33 ohms (approx. most headphones)> 1.15 vrms measured

Yes, at the OP Amp the output would likely be relatively constant/"regulated", but the resistor in line from the output of the OP Amp to the headphone jack causes a drop, thus the variance of output for external loads. Kinda just hinting at the OP may be not turning down the output of the headphones on the mixer to accommodate the change in output from different loading.
Click to expand...

My apologies Mark, a headphone amplifier, either a dedicated chip or "current boosted" op amp, will not collapse under load.
However that drop under worse-ish case loading is still only 4.8 dB and any load greater than 100 Ohms would go unnoticed.

Can I also say Mark how refreshing it is when people take the time and trouble to bloody MEASURE things?

Dave.
 
Thank you very much and you are so kind & friendly! Haaaa...

1. Yes, I was using the original power adapter came along with the box.

2. What and how should I check the Headphone amp by using the Digital Meter?
 
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