Budget DAC Review: behringer UMC204HD

[witold]

I tried almost everything: shorted jack, shorted XLR, emm-6 microphone, output from the other sound card. No difference. I turned off my desktop, my wi-fi router, all LED and CCFL lights. No difference. I think this signal doesn't came from outside. Why do I think so? Because 23kHz peak has always the same level, regardless of the gain settings. I hope links to a few screen-shoots will work. I tried to capture noise level with min-, mid- and max-gain. When the gain is set to the maximum, the peaks are buried in noise. When I was young there were problems with 50Hz and, maybe, local broadcast station. Now we have problem across the whole band .

 

[amirm]

OK, let me measure it when I get a chance.

BTW, to insert screen snapshots, just copy them to the clipboard and then paste here. Don't put IMG or anything around them.

 

[witold]

This time it must work. Three fresh screen snapshots (time stamp are in UTC). 192kHz, 24b, line, no pad.

 

[amirm]

It did.

 

[RayDunzl]

Here's my UMC202HD

Spectrum, forever averaging, 192kHz/24bit, sitting a few inches from a Plasma TV, on top of HDRadio, a few miles from a Transmitter farm, no input cables:

Turned off the TV and radio.

The TV is real noisy electrically, surprised there's not much difference.

The above was Channel 2. Here's the other channel, TV and Radio on again:

And with linear frequency display:

Channel 2

 

[Dimitri]

What's the software used above to capture the spectrum plots?

 

[Blumlein 88]

What's the software used above to capture the spectrum plots?

I believe that is REW.

Free and fantastic.

 

[Blumlein 88]

Here's my UMC202HD

Spectrum, forever averaging, 192kHz/24bit, sitting a few inches from a Plasma TV, on top of HDRadio, a few miles from a Transmitter farm, no input cables:

View attachment 10849

Turned off the TV and radio.

View attachment 10852

The TV is real noisy electrically, surprised there's not much difference.

The above was Channel 2. Here's the other channel, TV and Radio on again:

View attachment 10853

And with linear frequency display:

View attachment 10854

Channel 2

View attachment 10855

Obviously your graphs are fake. Everyone can hear the incredible breakdown of the soundstage with noisy stuff like TV in the area. No depth, grainy grunge, no there there. Who do you think you are fooling?

 

[Dimitri]

Thanks!!! Downloading ....please wait .....

 

[amirm]

See my tutorials on how to use it here: https://audiosciencereview.com/foru...om-measurement-tutorial-for-dummies-part-1.4/

 

[amirm]

Here is my measurements of its ADC @192 Khz sampling with nothing connected to its inputs, gain at max, pad = 0ff:

One channel is quiet (green). The other in blue has those spikes. First one is around 16 Khz, the second around 24, etc. They seem to be multiples of USB 8K buffers.

 

[RayDunzl]

My question about the ADC is in using it.

It seems to raise its own set of harmonics before getting near conversion of a tone to full scale, but I'm also not too confident in my method or test toys.

 

[witold]

In my case this unwanted signal drifts badly so I think it's origin is not related to x-tal controlled circuits. It must be something free-running and analog. DCDC converter for negative rail? I think it's time to open this box.

 

[Dimitri]

I think it's time to open this box.

Before (or after) you open the box, try taking the laptop and the interface away from your usual spot (different room, garage, bathroom, balcony and see if it's still behaving the same way.

 

[raif]

Hey, had a question about this dac, and would appreciate some input from you folks.

I typically have issues with usable volume on dedicated headphone amplifiers. For example, with the Desktop O2 amplifier on 1x gain, I am listening around 8 o'clock on the dial and competing with channel balances issues on the pot. This with a typical 2vrms output source and fostex th-x00 headphones.

This DAC sounds perfect. It measures very well, has a fixed output for a dedicated headphone amplifier and because of the lower output, should give me more room to work on the potentiometer.

Am I missing anything? As long as I am not running like 20 feet of RCA cables, this should be a good solution for my low volume listening, correct?

To articulate what I am asking:
Let's say we compare the umc204hd with something like the iDAC2 that has similar distortion levels relative to their output power.
Assuming I power the headphones to the same volume using a dedicated amplifier with plenty of headroom, would the relative performance be similar, just with with different positions on the pot(i.e. 12 vs 8 o'clock), or would the higher output DAC have better performance?

 

[Jimster480]

Hey, had a question about this dac, and would appreciate some input from you folks.

I typically have issues with usable volume on dedicated headphone amplifiers. For example, with the Desktop O2 amplifier on 1x gain, I am listening around 8 o'clock on the dial and competing with channel balances issues on the pot. This with a typical 2vrms output source and fostex th-x00 headphones.

This DAC sounds perfect. It measures very well, has a fixed output for a dedicated headphone amplifier and because of the lower output, should give me more room to work on the potentiometer.

Am I missing anything? As long as I am not running like 20 feet of RCA cables, this should be a good solution for my low volume listening, correct?

To articulate what I am asking:
Let's say we compare the umc204hd with something like the iDAC2 that has similar distortion levels relative to their output power.
Assuming I power the headphones to the same volume using a dedicated amplifier with plenty of headroom, would the relative performance be similar, just with with different positions on the pot(i.e. 12 vs 8 o'clock), or would the higher output DAC have better performance?

I don't think that the DAC with a higher output voltage would have better performance. But if you want to have more POT travel so that you have no channel imbalance then yes it could affect you. But really there shouldn't be issues with channel imbalance... my O2 has almost none and I regularly listen at 8-11 oclock.

 

[witold]

Mystery solved - unwanted peaks have their source in a 48V step-up converter (based on LM3488). And no, the on-off switch on the rear panel does not turn this circuit off. I can turn it off on the PCB, but I need 48V for my EMM-6 so I have to think more how to solve this problem.

 

[amirm]

Ah, good to know. Makes sense that there is a switching converter to produce 48 volt from usb 5 volt.

 

[sophie smith]

Greetings,
Was looking at UMC204 or 404 models primarily as a dedicated DAC to play music from PC. Can it function as a pre amp as well? I can connect it to my tube amp directly. I know it has low voltage output (1.2v), but my amp only has 1v input sensitivity, so it should work.
Looks like it has a volume control for main RCA out, which is what I plan to use.

Or should I get a dedicated preamp as well? Would prefer as few components as possible to keep everything simple.
Thanks

 

[Dimitri]

Looks like it has a volume control for main RCA out, which is what I plan to use.

Almost.
It has a volume control for main.
At least on the 204HD, main (controlled by the volume control on the unit itself) is TRS.