USB Audio (DAC) support, digital outputs

HawkStar

Hi - which USB port is used to output USB Audio?

rille

HawkStar
You can use any USB-Port.

jacob

rille is type C port is possible ? thank you

rille

jacob
What do you mean?

It has a USB-C port. It's USB 3 (AFAIK 5 Gbps) and it also supports video output.

jacob

rille sorry my question seem not clear enough , i mean type c port also support usb audio right ?

rille

You can use also the USB-C port for your DAC. But it makes no sense. USB 2.0 is fast enough for audio .

jacob

rille thank you, about usb audio , after did some testing with my DAC, i noted that dudu Os convert ( upsample, resample or whatever.. im not sure ) all bitrate to fixed 96khz, It's not bitpecfect

surfer63

Don't make the mistake to confuse a USB-C adapter port, or a USB-A or micro-USB with the USB protocol that is running over it. There is a difference between the adapter and the protocol.
The protocol USB 3.1x or USB 3.2x runs on USB-A, USB-B and usb-C adapters depending on the USB chip behind it.
And as the USB-C adapter becomes to then standard for chargers worldwide (also for stupid Apple), it might indeed be that newer, faster USB protocols will only run on the USB-C adapter.

rille

jacob I wrote that in the second post: "Of course there will be resampling to 96 kHz.". And even if you would have bitperfect output (like UAPP has) the DSP will resample. Most DSPs use 96 kHz so choosing 96 kHz for USB DAC was a good decision.

jacob

rille yes UAPP can do bitpefect , but there is a problem that when use Uapp with dac, it take control audio level . So other apps can not sound out a music anymore evenly i quit UAPP. Have to reset headunit or plug out usb cable from DAC to make it sound again. This is not too convenience for now, hopefully Dev will improve it in the near feature

dudu-langzi

rille The current digital output is a 48 kHz sample rate. However, it will be increased to 96khz later.

jacob

dudu-langzi its not about sample rate , its about resample process. Could it support an option that can purely using sample rate of the song i play, only apply for music app. I dont mind if i can not use radio, phone call, navigation sound…etc

rille

dudu-langzi
At digital output it's 48 kHz. But with USB DAC it's 96 kHz. Did I write anything different? I guess you didn't read the posts carefully...

jacob
If you want this use UAPP. You have to set the option: System->"Release USB audio driver on Home". This worked for me well. But the question is: which device do you have behind the USB DAC? Normally it's an DSP and the DSP will resample to it's internal sample rate. And I wouldn't overrate the bit-perfect output, especially in a car.

jacob

rille i did tried to use option "release USB audio driver on Home" but that's strange it not working. I will try again. I do connect DAC to my brax dsp used on car . Resample by android is not really good process, i did test and notice it very difference in a bad way

dudu-langzi

rille The current usbdac is in global mode. It definitely needs to be resampled, like you said.uappExclusive mode does what you say, but that results in no sound at all except for the player.

Mish82

Hi, I have been trying to output audio from my Dudu 7 with USB,

I have been using toslink (optical) to output audio up until now and still have the toslink cable plugged into the back of the unit. But I would like to output with USB.

I have set the USB Audio Output (beta ) function on and still can not output audio via USB.

I have also tried by connecting into the USB C port on the back of the unit and also have tried connecting to one of the 3 USB connections that go into the back of the unit also.

I can't seem to be getting any audio output out of the unit.

Is there anything I am missing to make it work?

rille

Which USB DAC do you use? And you must plug the Toslink cable to the USB DAC...

Eule

hi guys,
got myself a dudu7, and like it quite much. nice display (13 inch), responsive system, nice launcher.
as i also have a quite nice audio system, which gets fed by a toslink cable, i need the digital output.

using the internal spdif everything works. navigation,phone, radio, file playback (UAPP in play through Android mode)

BUT: not really happy with the sound, and it is lower volume.

connected a USB DAC (DSD TECH SH-AU02A from Aamzon, was the quickest way i could get one)

ok:
sound from UAPP now is perfect.

but: cannot get sound out of Radio, or Phone app.

navigation has sound, but only if i kill the UAPP task

option "release USB audio driver on Home" in UAPP is checked.

so, before i spend hours trying to get all that to work:

should it all work at all with a USB DAC connected, or am i trying something impossible? (BETA version of USB DAC support.....)

any ideas?
any updates?
any plan to fully support a USB DAC in the future?

or even better; change the current output behavior of the on board spdif ports?

greetings from Austria,
Michael

jacob

Eule when uapp app open , it will take control audio driver of android and leading to result other app can not out audio. Yes there is an option uapp said “ relased audio driver “ for other app. But it not work on my side also. Have to detach usb cable to dac or kill uapp to help android audio driver to retach again . Dudu7 and uapp is using 2 difference audio driver

rille

UAPP is exclusive, so no sound from other apps. If you set the option "release USB audio driver on Home" UAPP will release the USB device (if you press home and I don't know if it's working if UAPP is used as PIP app) and other apps can output sound over USB. But you can't use UAPP at the same time.

The UAPP USB support is another thing than the USB audio support of the headunit. UAPP should also work if you disable it because it has it's own USB driver. You can only use one of them at the same time. So it's not possible to listen to music with UAPP and get navigation messages. Possibly if you disable bit-perfect in UAPP.

Eule

rille

i know that UAPP is using its own drivers, so no sound for other apps while its active.
i can live with that.

but, as soon as i have a USB DAC connected, and UAPP not active (not even installed) i cannot get sound out of the radio app or the phone app.

if i could use UAPP and just quit it when i need to listen to the google maps app or make a phone call,
i would be perfectly fine with that.

best solution would be if the internal spdif would behave better.....

jacob

rille somehow i still can not make option release usb audio driver to home “ work , thats weired , everytime i have to turn of my dac , exit uapp to make other app like tidal , youtube working again.

Also i have problem with cracking / poping sound when open 360camera app when listening music from both uapp or other native app that using usb audio. Did you have this problem ?