USB DAC only offers 'analog stereo output'

General system Gaming, sound and video
1

I’m interested to find out why my cheap USB DAC (Behringer UCA222) only offers me ‘analog stereo output’ in the pavucontrol settings. I am sure it used to offer me a digital output option in the past.

The DAC is connected from a USB 3.0 port on my PC, and connects the other way via optical to my 2.1 system.

I can get audio to the 2.1 system, and it sounds good to me - I just find it odd that the PCM2902 driver for the USB DAC offers these options only. Perhaps it is just a quirk of the naming convention!

I’ve tried using USB 2.0 and USB 3.0 ports, as well as the LTS and zen kernels to see if it makes a difference, but there is not.

So, does anyone know more about this? I’ve included a screenshot of my configuration options (from the drop-down menu) in pavucontrol. Thanks in advance.

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2

I guess no-one knows? Or maybe it doesn’t matter!

3

from a quick web search i find this

A DAC, or digital to analogue converter, is the device that translates digitally stored information from a laptop, iPod or other such device into the analogue sound that we can hear.

is this not what you expected?

4

The output from the system is digital, not analogue. It only becomes analogue when it goes through the external DAC and, as it happens, I don’t use the analogue outputs. Therefore I would expect it to say ‘digital stereo output’.

However, it may just be a case of semantics.

5

Well never heard of this thing until now but my understanding is it converts to analog. I would assume the conversion happens before going to output and more than likely before going into the computer.

However since I just learned about this (nothing i need want or even care about lol) I don’t know how it actually works and where it does conversions

6

Thanks for the reply. I expect this is more about how the option is named rather than what signal it actually outputs - I was just curious!

7

Usually it works like this, the USB output is digital, in the DAC it’s converted from USB to I2S and then to analog.

With my DAC it’s “Digital Stereo (IEC958)”.

1 Like
8

I wonder why mine is different?

9

I’ve wondered about this before too.

I use a USB > Optical digital interface that sends coverts the USB audio signal from my laptop into a digital optical signal which is then sent to my DAC/headphone amp combo, which then converts the signal to stereo audio.

The digital interface only outputs a single, digital stream, and yet my system offers both and Analog Output and a Digital Stereo (IEC958) option for the device, both of which appear to work equally well.

Ultimately, it doesn’t seem to matter but I would like to know the reason why.