Budget DAC Review: behringer UMC204HD

[DonH56]

32,768 points? Otherwise you'd have to use a DFT or zero pad (etc.) to use an FFT...

There are a lot of articles on how FFTs can set the noise floor if not large enough and Amir's point about using the same record length when comparing is extremely important.

 

[thm_jpl]

Hi there. Welcome to the forum! And thanks for the additional measurements!

As to your question, for the purposes of measuring noise floor, your comparison is may NOT be valid. The fourier transform sizes have to be matched for that comparison. Mine uses 32,767 points. Match that and it should be close. Looking at how fine the "grass" is in the noise floor of your measurement, I suspect it is using a lot more taps in the transform causing the noise floor to artificially be lower than my measurements.

The distortion products are not affected by this.

One other variable is the noise of my measurement system versus the input ADC on that unit. On that front, I could not get as clean of a capture as you have. That is a pretty good ADC there.

Thanks, 131,072 point FFT was used. After switching to 32,767 points the noise floor does raise a few dB. Same with increasing the sample rate from 96kHz to 192kHz.
Although the effect is not too big, its still around -130dB (relative), or ~-136dBV.

Spec for output is: Maximum Output Level (0 dBFS) +10 dBu. The highest clean level I could get is -3dBV according to ARTA, above that the noise floor just comes up with the signal. I haven't checked the headphone out, it may be slightly better according to the specs (~1dB dynamic range).

Interesting to see all the differences in design when the two are essentially "built around" CS4272 https://audiosciencereview.com/foru...iew-behringer-umc204hd.1658/page-3#post-47791

 

[DonH56]

There is also this on the AP site: https://www.ap.com/technical-library/fft-scaling-for-noise/

I have the equations around for determining the fundamental noise floor of an FFT and processing gain but would have to dig a bit... Probably easier to search the 'net.

 

[amirm]

It is pretty simple Don: FFT gain in db =10*LOG10(B1/2) where B1 is "N". (this is from my Excel spreadsheet and hence the "B1").

 

[DonH56]

It is pretty simple Don: FFT gain in db =10*LOG10(B1/2) where B1 is "N". (this is from my Excel spreadsheet and hence the "B1").

Yep, duh, that's it. I had the more complicated formula for calculating the SFDR of a sampled system in mind, Bessel functions and all that jazz. Long day...

 

[Blumlein 88]

The simple formula is doubling lowers noise by 3 db.

So 131,072 FFT (also known as 128k FFT) is going to lower noise by 48 db if this were flat white noise.

So in the case of the Focusrite Solo if that were translated to the noise level for that whole band we are looking at -135db +48 for a noise floor of -87 db or thereabouts. Assuming no pollution by 60 hz hum or other issues etc. etc. which there usually are some. Natural noise floors are usually more pink than white so you probably could tack on some for that. Hopefully that gets to the flavor of the idea anyway. The noise floor of the Solo is probably around 90 db for that bandwidth roughly.

 

[Ecnob]

I'm glad I ran into this site. I've been trying to get into the world of high end audio recently (mostly for headphones), but finding good products has been extremely difficult because of the lack of objectivity in reviews. I come primarily from a science and PC gaming background and the amount of great, highly objective reviews for PC hardware/software is amazing, but it seems in the audio world there's nothing but subjectivity which is nice for personal impressions, but terrible for actual reviews. I don't care if an amp or DAC adds "weight" to the sound or is "airy". I want objective data, and there's a distinct lack of it it seems. However, this site seems pretty good and there's a lot of good data and discussion here considering how small of a community this is.

So I'm thinking of purchasing this interface because according to the measurements it works great as a DAC and it also allows me to do some music recording too, which previously I didn't have the right equipment to do properly. It even has the added benefit of a mic preamp so maybe I can get my modmic to sound even better, which is something I was looking for because there's still a good bit of noise with a cheap usb adapter, so I'm getting a ton of performance and functionality for less than the price of most good DACs. I was going to purchase a standalone DAC+headphone amp, but it looks like using this as a DAC and coupling it with a nice headphone amp (and maybe a speaker amp down the road) is the way to go.

I've been doing some more research, but I'm still confused on a few things before I buy this or something like this. So, in the manual (http://media.music-group.com/media/...C404HD_UMC204HD_UMC202HD_UMC22_UM2_QSG_WW.pdf) there's two different outputs (depending on the model) and they're labelled as 21 or 24. It seems there's no difference between the two as they describe 1/4 inch, RCA, and XLR outputs, yet if they're the same thing why are they labelled different? The description for 21 says "connect to powered studio monitors for playback and mixing"and for 24 it says "connect to external speakers for additional monitoring options". For the purpose of what I'm trying to do (output into headphone/speaker amp), does it matter which type I use? Is there a reason why some labelled are RCA jacks and others are 1/4inch. Is the difference just for cost saving measures or just for convenience (such as some audiences preferring 1/4inch over RCA as a hypothetical).

Also, does anyone know if the lower end ones use a worse DAC, or do they all use the same one? From the specs sheet it looks like the lower end ones are mostly the same with the only differences being the UMC22/UM2 not having 24bit audio support and the UM2 also has a different mic preamp. I was thinking about getting a lower end one because I don't need so many inputs/outputs, probably the UMC22.

 

[amirm]

Welcome to the forum! That is definitely what we are about.

As to different connector types, it is because they have a small box and want to serve both the pro recording space and consumer. So they have put in different connectors. Just buy the appropriate adapter for the use you have. I had to do that for some of my testing. The only trick is that some of the adapters are wired differently than others.

 

[Blumlein 88]

Thanks, 131,072 point FFT was used. After switching to 32,767 points the noise floor does raise a few dB. Same with increasing the sample rate from 96kHz to 192kHz.
Although the effect is not too big, its still around -130dB (relative), or ~-136dBV.

Spec for output is: Maximum Output Level (0 dBFS) +10 dBu. The highest clean level I could get is -3dBV according to ARTA, above that the noise floor just comes up with the signal. I haven't checked the headphone out, it may be slightly better according to the specs (~1dB dynamic range).

Interesting to see all the differences in design when the two are essentially "built around" CS4272 https://audiosciencereview.com/foru...iew-behringer-umc204hd.1658/page-3#post-47791
View attachment 10062

Looking at the specs for the Solo they list 92 db noise level for the line outputs. So that is probably why you aren't getting a lower noise floor in a loopback. The ADC itself should be several db better than that according to their specs.

 

[Blumlein 88]

I'm glad I ran into this site. I've been trying to get into the world of high end audio recently (mostly for headphones), but finding good products has been extremely difficult because of the lack of objectivity in reviews. I come primarily from a science and PC gaming background and the amount of great, highly objective reviews for PC hardware/software is amazing, but it seems in the audio world there's nothing but subjectivity which is nice for personal impressions, but terrible for actual reviews. I don't care if an amp or DAC adds "weight" to the sound or is "airy". I want objective data, and there's a distinct lack of it it seems. However, this site seems pretty good and there's a lot of good data and discussion here considering how small of a community this is.

So I'm thinking of purchasing this interface because according to the measurements it works great as a DAC and it also allows me to do some music recording too, which previously I didn't have the right equipment to do properly. It even has the added benefit of a mic preamp so maybe I can get my modmic to sound even better, which is something I was looking for because there's still a good bit of noise with a cheap usb adapter, so I'm getting a ton of performance and functionality for less than the price of most good DACs. I was going to purchase a standalone DAC+headphone amp, but it looks like using this as a DAC and coupling it with a nice headphone amp (and maybe a speaker amp down the road) is the way to go.

I've been doing some more research, but I'm still confused on a few things before I buy this or something like this. So, in the manual (http://media.music-group.com/media/...C404HD_UMC204HD_UMC202HD_UMC22_UM2_QSG_WW.pdf) there's two different outputs (depending on the model) and they're labelled as 21 or 24. It seems there's no difference between the two as they describe 1/4 inch, RCA, and XLR outputs, yet if they're the same thing why are they labelled different? The description for 21 says "connect to powered studio monitors for playback and mixing"and for 24 it says "connect to external speakers for additional monitoring options". For the purpose of what I'm trying to do (output into headphone/speaker amp), does it matter which type I use? Is there a reason why some labelled are RCA jacks and others are 1/4inch. Is the difference just for cost saving measures or just for convenience (such as some audiences preferring 1/4inch over RCA as a hypothetical).

Also, does anyone know if the lower end ones use a worse DAC, or do they all use the same one? From the specs sheet it looks like the lower end ones are mostly the same with the only differences being the UMC22/UM2 not having 24bit audio support and the UM2 also has a different mic preamp. I was thinking about getting a lower end one because I don't need so many inputs/outputs, probably the UMC22.

First welcome to the forum. Glad you are here.

Here is a picture of the 204 HD so you can see the connectors better.

The playback outputs are regular RCA plugs most consumer gear uses. The Main Out is a balanced quarter inch plug that would fit most pro monitors or other pro gear.

Here is the 404HD back panel. It has both RCA and balanced 1/4 inch as well as adding balanced XLR outputs. Again XLR's would be on many pro monitors or other pro gear.

I believe the RCA playback outputs are fixed on the Uphoria series. On the 404HD I think the playback 1/4 inch outputs will also be fixed. On page 27 of the linked manual for volume knob (item #15) it says for the 204 and 404HD models this controls the level of the Main outs. Leading me to think the playback outputs are going to be fixed in level and not controlled by the front volume knob. Main outs are expected to be connected to powered monitors and control the volume of those monitor speakers. You can get adapters as Amir said if you need to go from volume controlled 1/4 inch or XLR connectors into an RCA plug.

 

[Ecnob]

So that's where I'm a little confused. If I use a one of the fixed outputs (meaning no volume control) I just plug it into the headphone/speaker amp with volume control. If I were to use the outputs controlled by a volume knob on the interface and plug those into a amp I would have volume control on both the interface and the amp correct? Say I have the knob on the amp set to 12 o'clock and keep it there. Would setting the volume knob on the interface on the "controlled" outputs to the highest level result in the same volume coming through the speakers/headphones as using one of the fixed interface outputs plugged into an amp? Is there any specific advantages for one type of connection over the other in terms of issues like noise floor or are they interchangeable and for my purpose it doesn't matter (interface as a DAC into headphone amp)? I was under the impression that a line out signal should be fixed so I don't get why you can adjust them, or are the variable outputs not line out?

 

[Blumlein 88]

So that's where I'm a little confused. If I use a one of the fixed outputs (meaning no volume control) I just plug it into the headphone/speaker amp with volume control. If I were to use the outputs controlled by a volume knob on the interface and plug those into a amp I would have volume control on both the interface and the amp correct? Say I have the knob on the amp set to 12 o'clock and keep it there. Would setting the volume knob on the interface on the "controlled" outputs to the highest level result in the same volume coming through the speakers/headphones as using one of the fixed interface outputs plugged into an amp? Is there any specific advantages for one type of connection over the other in terms of issues like noise floor or are they interchangeable and for my purpose it doesn't matter (interface as a DAC into headphone amp)? I was under the impression that a line out signal should be fixed so I don't get why you can adjust them, or are the variable outputs not line out?

Yes, the fixed line outs would be appropriate for sending onto a headphone amp with its own volume or a home stereo which has its own preamp.

The Main out is for powered monitors or the amp to speakers. It also is usually a higher voltage though I think in this particular case that may be variation of the same lower voltage at the line outs. Generally if you don't need a volume control in series with the signal one is better to leave it out. As for which has better noise floors and such that will vary from one piece of gear to another. I don't know the relative values for this particular unit.

 

[sonci99]

Hi, I found this thread searching for a Dac..
It seems nice for the price, but I need SPIDF in. Do you know any similar Behringer Dac with optical in?

 

[amirm]

Welcome to the forum. The topping d30 dad is my current recommendation for budget dad and it has spdif input.

 

[sonci99]

Welcome to the forum. The topping d30 dad is my current recommendation for budget dad and it has spdif input.

It seems interesting and it even plays DSD. Have you measured it? I guess it's better than the Modi2

 

[stunta]

It seems interesting and it even plays DSD. Have you measured it? I guess it's better than the Modi2

Welcome!

I am selling mine if you are interested. Review link is at the bottom.

https://audiosciencereview.com/forum/index.php?threads/topping-d30.2314/

https://audiosciencereview.com/forum/index.php?threads/topping-d30-dac-measurement-and-review.2016/

 

[amirm]

It seems interesting and it even plays DSD. Have you measured it? I guess it's better than the Modi2

Of course. https://audiosciencereview.com/forum/index.php?threads/topping-d30-dac-measurement-and-review.2016/

It is far superior in both build quality and measured performance than Schiit Modi 2.

 

[witold]

Hi, I found this thread searching for an explanation/solution of unwanted peaks in the spectrum from ADC from UMC202HD. In post # 182 I saw a spectrum very similar to mine so I read all posts in this thread. But I didn't find even one complaint against these unwanted spurious signals.
Here is my problem: regardless of the configuration (sampling frequency, resolution, + 48V power supply on/off, desktop / laptop ...) my UMC202HD has a quite strong peak around 23kHz. This is my second device, because in the first U-phoria this tone was much lower (10 kHz) and I could literally hear it. The 2nd device is much better but this 23kHz peak annoys me. Maybe someone already discovered what is the source of this tone?

 

[amirm]

How did you measure it? Did you short out the inputs before capture?

 

[RayDunzl]

How did you measure it? Did you short out the inputs before capture?

Testing the ADC function is supposed to be on your TODO List.

My prior request.