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What type of audio output does pi0 w give as default via USB?

I am looking to get some high quality audio out of a pi0 w and have a small touchscreen hat so I am hoping to get I2S sound out the usb port. Is it already being delivered as such in a default Rasbian setup or does it provide PMW?

If it provides PMW, is it possible to reconfigure it? I have only seen tutorials on how to push I2S out some of the pins, but currently I would like to use most of the needed pins for my touchscreen.

I will be doing all of my audio processing in an external unit that is shielded as well as providing amplification for larger speakers and have no other need for the usb port so it makes sense to send audio that way through a DAC and on to an amp.

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    i would think that it depends on the hardware that you plug into the usb port
    – jsotola
    Commented May 22, 2018 at 6:33
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    The pi uses PWM on the GPIO for a very basic sound output, USB is a serial bus which can be used to connect lots of things - if you are looking for a soundcard how it works varys but it will be presented to the system (if there are the correct drivers) as an audio sink. So if you are looking for a USB DAC/soundcard just find one that has linux drivers (or is known to work on the Pi), and then set up the program output accordingly
    – Wilf
    Commented May 22, 2018 at 7:38
  • Thanks @Wilif, I get how to configure the USB soundcard/DAC analog audio output. What I am trying to be sure is I am giving the USB device the highest quality digital audio input to work with.
    – pathfinder
    Commented May 23, 2018 at 19:58

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The data USB port on the Raspberry Pi Zero can only act in USB host or USB device mode. It cannot be reconfigured to provide I2C or PWM signals at all. In USB Host mode, you can use most USB Soundcards. How that soundcard works internally is completely irrelevant as long the drivers are included in Raspbian. Your best bet if the soundcard driver is already inside the official Linux kernel from kernel.org too.

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  • So what your saying is that it will depend on what the dac or sound card asks for will be what is provided to it?
    – pathfinder
    Commented May 22, 2018 at 15:06
  • It seems to me that you want to learn about USB to I2C bridges ;) Ask a new question, so i can search some good sources ...
    – flakeshake
    Commented May 22, 2018 at 19:03
  • I am currently reading the shairpoint-sync documentation (which is the program I need to use to handle the incoming audio data) and it may be a moot point, it seems that setting config properly there and in my alsa settings I will be getting the highest possible quality that shairpoint-sync is able to handle. Also, it is not I2C that I need, it is I2S. Not sure if you are meaning I2S, but saying I2C. After some more research I may add a new question and will post as a comment link here. Thanks for your help :)
    – pathfinder
    Commented May 23, 2018 at 19:55

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