[Qata]

I have an old Native Instruments Guitar Rig Mobile I/O USB audio device that outputs 24/192 on a single stereo out, 1/4. Below are the specs which I guess are divided between "line outputs" and "headphone output" because it depends on what the output is used for, however, there is actually only the 1 stereo out that all these specs are describing.
 
My question is whether this is the equivalent of a headphone amp. I plan on getting a Beyerdynamic DT-990 Pro 250 ohms to use with this but could this even power the 600 ohms version?
 
Thanks.
 
Line Outputs:
Output Impedance 100 ohms unbalanced, 200 ohms balanced
Maximum Output Level +14.9 dBu
SNR (weighted) 100 dBu
THD+N 0.006%
Frequency Response (+/- 1 dBu) 10 - 40000 Hz
 
Headphone Output:
Load Impedance 16 - 600 ohms
Maximum Output Level (100 ohms load)
2.165 V RMS (load 100 ohms), 4.345 V RMS
(no load)
SNR (weighted) 100 dB
THD+N (100 ohms) 0.06%
Frequency Response (+/- 1 dBu) 10 - 40000 Hz

 

[NA Blur]

Yes this can be used as a headphone out, but it would great to have the output impedance of the headphone back in hopes that it is below 10 Ohms.

 

[Qata]

Thanks! Unfortunately, this goes right over my head as I don't understand the tech too well. The 2nd part of your sentence just makes no sense to me.
 
I do know that it can be used as a headphone output, it is designed to be. But not necessarily as a headphone amp, it wasn't advertised to be and that's why I am asking. 
 
 
I was just wondering if it would effectively power 250 ohms or even 600 ohms headphones to do justice to their full potential or if it is too weak.
 
I don't know why it says "100 ohms unbalanced, 200 ohms balanced" and then "Load Impedance 16 - 600 ohms" and then "Maximum Output Level (100 ohms load)"?
 
What ohms rating is it?

 

[NA Blur]

Ohms are a unit of resistance. Think clamping a hose as adding ohms to the flow of water and in electronics resistance impedes the flow of current. The lower the resistance ( ohms ) the easier it will be for current to flow.
 
The output impedance of an amp, in our case a headphone amp, is important not only to not impede the flow of current to the headphone driver, but to also properly damp the driver resonance. The driver as you know is like a little speaker. As it moves back and forth it can develop oscillations called resonances. These can be good or bad depending on how they alter the sound. If these resonances add distortion to the audio then it is bad. To remove some of the resonance that the driver may incur is to dampen the signal to the driver. This allows the signal to not develop electronic resonances that may add distortion. You can read more about audio damping factors on wiki, but it is going to be a dry read unless you like tech speak.
 
So resistance, those pesky Ohms again, are important especially at the headphone output of amps and of the headphone. One really important thing to know is resistance is not the primary factor in determining if a device will drive a headphone loud enough. This is the biggest misunderstanding I find in the community. The first thing to look at is the sensitivity of a headphone well before the resistance. I have a pair of headphones that have over 1000 Ohms and they can be driven by any of my amps easily. How can this be? The sensitivity is high enough that anything can drive them. My general rule is if the sensitivity of a headphone is over 102dB / mW then the headphone can easily be driven by portable and desktop amps. If the headphone has a sensitivity below 102dB it may develop issues with some low-output devices like a phone.
 
It can be complicated at first, but just remember that resistance is more important on the output side of the amp and sensitivity is more important than resistance for headphones.
 
In my first response I was asking if you knew or can find the output impedance of the headphone output on your amp? Hopefully it is below 10 Ohms which will give optimal damping for a large array of headphones. If the headphone output has an impedance of over 100 Ohms it may add distortion from poor damping.
 
Hope this helps a bit and be sure to let us know how you setup goes and how it sounds.