NUC USB C Audio

[Tapatrick]

I have an NUC8i5BEH - is the way audio output is implemented in these NUCs the same through the standard USB ports or through the Thunderbolt /USB C port? 

[LeonWaksman]

I'm not sure that I've understood your question correctly. Any way, please read para. 1.5.1.7, page 13 in the Technical Product Specification. Please see the first item in table on page 2.

Leon

[Tapatrick]

Thanks Leon, appreciate your help.

I wasn't sure if the audio output that comes from the standard USB ports was routed or implemented differently from the USB C port.

The table you mention shows that HDMI and USB C ports treat the audio to the same standards but I'm not clear if the standard USB (A) ports are different.

Patrick

[LeonWaksman]

Hi Patrick,

There is no audio output from the USB-A ports, unless you connect USB to Audio adapter (for example like this one).

Leon

[Tapatrick]

Thanks Leon,

You say there is no audio from the standard USB ports. I understand there is an analogue audio output from the jack plug on front. I do get (digital) audio from the standard USB ports (into a separate DAC). I know lots of people that use this method.

I wanted to know if the USB C port implements audio in a different or better way than the standard USB ports. I will try it out and see.

[n_scott_pearson]

There is no audio output capability over the USB-A ports.

Digital audio is available via HDMI and DisplayPort (it is a DisplayPort output that is available via the Thunderbolt/USB-C ports). In this case, the number of channels supported is dependent upon what (HDMI or DisplayPort) device is connected.

Unless you have one of the new units that doesn't have it populated, there is also a separate audio CODEC that supports the output of analog audio via the Front Panel audio port. This is exclusively stereo, I believe.

Hope this helps,

...S

[Tapatrick]

Thanks Scott,

You also say there is no audio from the standard USB ports, but I do get (digital) audio from these USB ports (into a separate DAC). I know lots of people that use this method.

I wanted to know if the USB C port implements audio in a different or better way than the standard USB ports. I will try it out and see.

Thanks Patrick

[ClariceStarling]

Analog audio on my NUC is amazingly good sound!

[Tapatrick]

Cheers!

[n_scott_pearson]

There is no audio device in the system design that is blindly outputting audio to/via the USB-A ports. If you happen to have an USB audio device plugged into a USB-A port, then the device driver that is supporting that device will communicate audio data to that device over the USB-A port. Saying this another way, in the case of a USB DAC device, as an example, there is a device driver running on the system that supports this DAC and transmits audio data to it in some format (number of channels, etc.; whatever the DAC device reports it can consume).

So, to answer your question, like the USB-A port case, there is normally no audio data flowing out through the USB portion of the USB-C signals. There are two exceptions,

1. There is a USB DAC (or similar audio device) plugged into the USB-C port (or a downstream hub). In this case, the transmission of data to this device from the supporting device driver would be identical to the data sent to the device if it had been plugged into a USB-A port.
2. There is a device plugged into the USB-C port that can consume the DisplayPort signal that may also be embedded in the USB-C signals. In this case, the DisplayPort signal itself contains an audio output stream and this stream will have been tailored (by the Intel HD Audio driver) to match the capabilities (number of channels, etc.) that this device reported it supports.

Clear as mud?

...S

[Tapatrick]

Brilliant and clear as a bell!
Now we are getting some where.
We are getting into the weeds here but a couple of questions come to mind:
1. Is the HD audio contained in the stream (ignoring any video channels) from the USB C port (of course depending on any attached devices ability to utilise) different from any audio that would be routed through the USB A ports to an attached DAC?

2. In the same way do you know how different is the circuitry that the audio streams take through the USB C and A ports. (And even how different are the routes to the different USB A ports). Ie which if any is shorter or less complicated?

[n_scott_pearson · Accepted solution]

Definitely into the weeds...  ;^)

1. I am not sure what kind of answer you are looking for here. The bitstream or PCM format and capabilities used is determined by the device being connected. This is (as) true for the audio data going to a DAC device as it is for the audio data embedded in the AV signal going to a Receiver/TV/SoundBar.
2. In general, you could have a USB port that is supported directly by the chipset. Alternatively, you may have a port that is provided by a secondary USB hub (and this hub may be a standalone PCIe device or below a chipset USB port). In the USB-C case, the path can be even more complicated. USB-C requires a separate chip to manage the negotiation of data transmission and reception - and, if the port also (or alternatively) supports Thunderbolt, there may be a separate chip for that. Regardless, the digital audio signal (for, say, the DAC device) is simply output by the DAC's driver to the USB driver and is then carried across the medium and input by the DAC device. It is not affected by the complications of the circuitry or path - well, except for cases where there might be bandwidth issues. For example, if you have a dock device that supports multiple USB devices and monitors and data streams, there may be limitations on data rates and cases where a lower quality audio format might have to be used because of the limitations (but this could be negotiated completely unbeknownst to you).

I am not sure that I have answered the questions as you desired. Remember that there are tons of good articles in Wikipedia that you can use as a starting point to building an understanding of this stuff. Start with the USB and USB-C articles on the one side and the audio articles on the other.

Hope this helps,

...S

[Tapatrick]

Thanks ...S,
you have been very helpful

[ClariceStarling]

I just bought an analog speaker system because it was cheaper.  But now I see a surprising number of people with expensive computers still use analog, because they want to save their USB ports for other things ... so I feel better now!