This is a review and detailed measurements of the UA Twin X Quad (also comes in Duo). It was kingly sent to me by the company for testing. The Quad version as I have costs US $1,400. The Duo version is cheaper. This designation refers to the number of cores for internal DSP which performs various audio processing internally including emulation of some other manufacturer inputs.
As desktop interfaces go, the Twin X is kind of hefty which is nice as it will stay put better:
The unit is powered by an external adapter with nice locking barrel connectors:
There are only two inputs: Toslink and Thunderbolt. Unfortunately Thunderbolt support is only for 64 bit applications which my Audio Precision interface is not. I had to use my Roon player for a bit of testing using TB and then Toslink for the rest. Since there is no other digital input, I could not fully test the ADC.
Sorry about that.
UA Twin X Measurements (DAC):
As noted, I used Roon to play my reference 1 kHz tone and measured the response using the Monitor outputs adjusted for 4 volts out:
This is good performance but can't keep up with our desktop products that are optimized for 4 volt output:
Fortunately performance improves if you allow higher output levels:
Jitter test showed a few unwanted bits and somewhat elevated noise floor:
From here on, I switched to Toslink. Linearity was perfect:
IMD versus level though showed the dreaded "ESS IMD Hump:"
What a shame that ESS did not resolve this on their own leaving each adopter to invent their own solution. Seeing how it involves optimizing a couple of passives, it is borderline criminal on their part.
Dynamic range is excellent at full output and very good at 4 volts:
The internal clock was set to 48 kHz so I ran my filter test at that frequency:
We see good attenuation but rather slow roll off that is so typical.
ADC+DAC Measurement
I figured I test the ADC indirectly by using analog in and out as if the unit was a pre-amp. Alas, I could not figure out how to put the unit in Line input mode. The only thing that worked was the high gain mic input so I went with it:
As we see distortion is excellent at better than -120 dB. Noise pulls overall performance down which is natural given the high amplification. I am guessing the ADC would be around 110 dB SINAD or something like it.
Headphone Out Measurements
Budget interfaces have barely usable headphone interfaces. Let's see if Twin X is better starting with 300 ohm load:
Not bad! We have plenty of power. Distortion and noise would have been really good had the DAC not increased distortion as noted earlier in IMD test.
Same is true of 32 ohm load, albeit with another distortion source:
Still, you should be able to drive plenty of headphones with this output.
Conclusions
If you are an audiophile, this is not a product for you. It has a lot of extra functionality you are paying for which you won't need and makes the device more expensive and harder to use. For professional applications, my measurements would be a subset of what you need to make a purchase decision. Overall, the DAC performance is excellent for this class of device, sans the IMD hump. I am hopeful company can make the minor circuit change to get rid of it. Headphone output is competent. And while I could not test the the ADC much, from the bit I played with, it seems performant.
Overall, I can recommend the UA Twin X with some minor reservations per above.
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As always, questions, comments, recommendations, etc. are welcome.
Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
As desktop interfaces go, the Twin X is kind of hefty which is nice as it will stay put better:
The unit is powered by an external adapter with nice locking barrel connectors:
There are only two inputs: Toslink and Thunderbolt. Unfortunately Thunderbolt support is only for 64 bit applications which my Audio Precision interface is not. I had to use my Roon player for a bit of testing using TB and then Toslink for the rest. Since there is no other digital input, I could not fully test the ADC.
Sorry about that. UA Twin X Measurements (DAC):
As noted, I used Roon to play my reference 1 kHz tone and measured the response using the Monitor outputs adjusted for 4 volts out:
This is good performance but can't keep up with our desktop products that are optimized for 4 volt output:
Fortunately performance improves if you allow higher output levels:
Jitter test showed a few unwanted bits and somewhat elevated noise floor:
From here on, I switched to Toslink. Linearity was perfect:
IMD versus level though showed the dreaded "ESS IMD Hump:"
What a shame that ESS did not resolve this on their own leaving each adopter to invent their own solution. Seeing how it involves optimizing a couple of passives, it is borderline criminal on their part.
Dynamic range is excellent at full output and very good at 4 volts:
The internal clock was set to 48 kHz so I ran my filter test at that frequency:
We see good attenuation but rather slow roll off that is so typical.
ADC+DAC Measurement
I figured I test the ADC indirectly by using analog in and out as if the unit was a pre-amp. Alas, I could not figure out how to put the unit in Line input mode. The only thing that worked was the high gain mic input so I went with it:
As we see distortion is excellent at better than -120 dB. Noise pulls overall performance down which is natural given the high amplification. I am guessing the ADC would be around 110 dB SINAD or something like it.
Headphone Out Measurements
Budget interfaces have barely usable headphone interfaces. Let's see if Twin X is better starting with 300 ohm load:
Not bad! We have plenty of power. Distortion and noise would have been really good had the DAC not increased distortion as noted earlier in IMD test.
Same is true of 32 ohm load, albeit with another distortion source:
Still, you should be able to drive plenty of headphones with this output.
Conclusions
If you are an audiophile, this is not a product for you. It has a lot of extra functionality you are paying for which you won't need and makes the device more expensive and harder to use. For professional applications, my measurements would be a subset of what you need to make a purchase decision. Overall, the DAC performance is excellent for this class of device, sans the IMD hump. I am hopeful company can make the minor circuit change to get rid of it. Headphone output is competent. And while I could not test the the ADC much, from the bit I played with, it seems performant.
Overall, I can recommend the UA Twin X with some minor reservations per above.
-----------
As always, questions, comments, recommendations, etc. are welcome.
Appreciate any donations using: https://www.audiosciencereview.com/forum/index.php?threads/how-to-support-audio-science-review.8150/
