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Universal Audio Apollo Twin X Review (Audio Interface)

amirm

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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:

Universal Audio Twin X Review Quad Audio Interface review 2021.jpg


The unit is powered by an external adapter with nice locking barrel connectors:

Universal Audio Twin X Review Quad Audio Interface review Power Supply.jpg


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:

Universal Audio Twin X Measurements Audio Interface review 2021.png


This is good performance but can't keep up with our desktop products that are optimized for 4 volt output:
Best Audio Interface review 2021.png


Fortunately performance improves if you allow higher output levels:

Universal Audio Twin X Measurements THD+N vs Level Audio Interface review 2021.png


Jitter test showed a few unwanted bits and somewhat elevated noise floor:

Universal Audio Twin X Measurements Jitter Audio Interface review 2021.png


From here on, I switched to Toslink. Linearity was perfect:
Universal Audio Twin X Measurements Linearity Audio Interface review 2021.png


IMD versus level though showed the dreaded "ESS IMD Hump:"

Universal Audio Twin X Measurements IMD Distortion Audio Interface review 2021.png


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:

Universal Audio Twin X Measurements Dynamic Range Audio Interface review 2021.png


The internal clock was set to 48 kHz so I ran my filter test at that frequency:
Universal Audio Twin X Measurements DAC filter Audio Interface review 2021.png


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:

Universal Audio Twin X Measurements Mic Input Monitor Out Audio Interface review 2021.png


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:

Universal Audio Twin X Measurements Power into 300 ohm Audio Interface review 2021.png


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:

Universal Audio Twin X Measurements Power into 32 ohm Audio Interface review 2021.png


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/
 

Moonhead

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Awesome Amir, much obliged :)
 

Music1969

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Hi @Dave Tremblay

Some questions if you could kindly assist:

1. Can you kindly comment on the 'ESS IMD hump' here?

2. Is this interface using different ESS DAC chip to your X16, which has no signs of the ESS hump.

3. And have Universal Audio engineers discussed with ESS Labs themselves - do they offer any advice to solve this? Are they aware of it? Do they even care or are they indifferent?

4. Does Universal Audio think there is any audibility impact with this hump? Or Universal Audio don't think it's an issue at all, either audibility or engineering issue?

Thanks!
 

YSC

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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:

View attachment 113048

The unit is powered by an external adapter with nice locking barrel connectors:

View attachment 113049

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:

View attachment 113050

This is good performance but can't keep up with our desktop products that are optimized for 4 volt output:
View attachment 113051

Fortunately performance improves if you allow higher output levels:

View attachment 113052

Jitter test showed a few unwanted bits and somewhat elevated noise floor:

View attachment 113053

From here on, I switched to Toslink. Linearity was perfect:
View attachment 113054

IMD versus level though showed the dreaded "ESS IMD Hump:"

View attachment 113055

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:

View attachment 113056

The internal clock was set to 48 kHz so I ran my filter test at that frequency:
View attachment 113057

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:

View attachment 113058

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:

View attachment 113059

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:

View attachment 113060

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/
Just as a joke: so does this means if I am an audiophile this is a waste of money and if I am a pro, this review serves little?;):D
 

LTig

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For pure raw performance the RME ADI-2 PRO is the better choice. However the internal DSPs are probably why one would buy it if one has an application on hand. And if one uses distortion based sound "enhancement" plugins the ESS hump probably is swamped in the plugins distortion anyway.
 

Adahn

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For professional applications, my measurements would be a subset of what you need to make a purchase decision.

Thanks for the review, but here's the problematic bit. To my knowledge, there isn't anybody providing the full set of measurements on all these interfaces. Manufacturers manipulate the spec sheets with lies of omission, providing half truths at best, and there's no real way of knowing what you're buying.

What I'm getting at, is that it would be a great service if you could look at pro audio a bit more closely. I believe the amount of snake oil in the industry is even worse than audiophile levels.

And it would be great if you could separate ADC measurements to preamp and line (for devices that allow bypassing the preamps).
 

fordiebianco

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Er, but what does it do? I'm a bit confused by the guitar and headphone adapters on the front and the microphone inputs.
 

Blumlein 88

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Thanks for the review, but here's the problematic bit. To my knowledge, there isn't anybody providing the full set of measurements on all these interfaces. Manufacturers manipulate the spec sheets with lies of omission, providing half truths at best, and there's no real way of knowing what you're buying.

What I'm getting at, is that it would be a great service if you could look at pro audio a bit more closely. I believe the amount of snake oil in the industry is even worse than audiophile levels.

And it would be great if you could separate ADC measurements to preamp and line (for devices that allow bypassing the preamps).
This times 100.

There are a few places doing measurements on consumer audio. You would have pro audio all to yourself. I get the Pro side isn't of main interest to many here, but maybe Audio Science could embrace the recording side more than it does.
 
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Blumlein 88

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Er, but what does it do? I'm a bit confused by the guitar and headphone adapters on the front and the microphone inputs.
It can function as a DAC for playback.

It also can record.

So microphone inputs for recording what is put in front of a microphone.

Guitar inputs for recording guitars.

Also has a headphone amp for both headphone playback and monitoring what is being recorded. Plus it has line outputs which can go to active speakers.

It has functions normally referred to as an audio interface or audio recording interface. Get some microphones, and a computer and you have all you need to create music tracks.
 

abdo123

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This times 100.

There is a few places doing measurements on consumer audio. You would have pro audio all to yourself. I get the Pro side isn't of main interest to many here, but maybe Audio Science could embrace the recording side more than it does.

It’s not like people are sending him pro interfaces and he’s saying no.

At the same time you can’t expect him to purchase pro audio equipment on his own. The prices are ridiculous.
 

Blumlein 88

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It’s not like people are sending him pro interfaces and he’s saying no.

At the same time you can’t expect him to purchase pro audio equipment on his own. The prices are ridiculous.
I'm not bothered about him doing more or less than he has. Heck I can't see how he reviews the amount he does. I'm not asking he spend big money for these or any money. Just let people or companies send them as he is doing so far.

What I'm wanting is a more thorough investigation of the pro units on the ADC, microphone pre, and pre amp side. I get the reviews are heavily weighted toward playback. I'd like to see the other half given as much investigation. There are a fair number of people interested in that as an untapped audience for ASR.
 
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fordiebianco

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It has functions normally referred to as an audio interface or audio recording interface. Get some microphones, and a computer and you have all you need to create music tracks.

Many thanks for the clarification. It does everything my Line 6 UX2 does, but in a smaller package and probably better engineered.
 

JohnYang1997

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Hi @Dave Tremblay

Some questions if you could kindly assist:

1. Can you kindly comment on the 'ESS IMD hump' here?

2. Is this interface using different ESS DAC chip to your X16, which has no signs of the ESS hump.

3. And have Universal Audio engineers discussed with ESS Labs themselves - do they offer any advice to solve this? Are they aware of it? Do they even care or are they indifferent?

4. Does Universal Audio think there is any audibility impact with this hump? Or Universal Audio don't think it's an issue at all, either audibility or engineering issue?

Thanks!
I can answer these questions.
1, It's noise modulation issue on 901x series DACs. This is different from the actual imd increase at that range.
2, Of course it's different this is much much cheaper machine.
3, Can't be solved.
4, Likely not nor important. This is very down in level. For years tons of music was created on machines perform way worse and people are trying to emulate them. I don't think it will be audible even less so than the actual imd increase in the 9038pro/q2m.
 
OP
amirm

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What I'm getting at, is that it would be a great service if you could look at pro audio a bit more closely. I believe the amount of snake oil in the industry is even worse than audiophile levels.
I am looking closely. My comment there was not about this but rather the fact that I am not qualified to review all the features these products have. I am 100% focused on measuring their performance. And will test all the products that are loaned to me.

In general, even though we have many Pro users in this forum, very few send in anything to be tested. I realize they use them everyday but when purchasing something new, they could route them through me for testing.
 

Blumlein 88

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Many thanks for the clarification. It does everything my Line 6 UX2 does, but in a smaller package and probably better engineered.
Looks like your unit is oriented heavily toward guitarists. I've never heard of it, but looked it up. Pretty cool looking unit.

But yes basically same idea in broad terms.
 
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amirm

amirm

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And it would be great if you could separate ADC measurements to preamp and line (for devices that allow bypassing the preamps).
I do this normally. As I explained however, there is no way for me to test the ADC on this unit because it only exposes a 64-bit ASIO interface which my Audio Precision 32-bit app cannot see. UA products are the only ones so far that I have seen this limitation. For all others I have a dedicated section for ADC.
 

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Adahn

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I am looking closely. My comment there was not about this but rather the fact that I am not qualified to review all the features these products have. I am 100% focused on measuring their performance. And will test all the products that are loaned to me.

In general, even though we have many Pro users in this forum, very few send in anything to be tested. I realize they use them everyday but when purchasing something new, they could route them through me for testing.

I really appreciate the work you're doing for the benefit of the community and thank you for it. Merely pointing out that there's been very few pro audio reviews in general and they don't seem to follow a set pattern of tests, so they're barely even comparable between them.

As I said, some reviews test preamps while others test line, sometimes there's a headphone amp test, others not, the graphs have different units/scales, stuff like that, that I observed while browsing through previous reviews.

You've got a pretty good template going on for most other electronics by now, so we can easily see all the important bits and make comparisons. Would love to see an extensive set of standardized measurements applied to ADC/DAC devices too.

As for the problem of finding them in order to measure them, not everyone lives in NA for mailing stuff, and I believe the more practical longterm approach would be simply buying equipment, funded by the monetization of this site and then flipping them on ebay after testing.
 
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