EDIT: The instructions here no longer work - please see the Enhanced Digital Output app for support of usb dacs. These experiments are closed except for tests on specific dacs to improve support.
As reported by John S I've been looking at support for async usb dacs connected to the Usb port of Touch. I believe I've made some progress and have some changes to the touch firmware which I believe are worth sharing. At present this is really a proof of concept and I am looking for testers who have an async usb dac (usb 1.1 devices for the moment) and are willing to try some tests.
I've been testing these modifications with a usb 1 dac (Audiolab MDAC) - it will play at 44.1 and 48k sampling rates with my modified kernel. (The dac is capable of 96k, but to make it work with Touch at present I've modified the kernel to only support these lower rates)
The process for installing the updates is slightly involved, but should all be able to be done from the normal user interface. Instructions below:
1) Update to latest released Touch firmware
2) Perform factory reset to ensure any previous usb mods are removed
3) Add the following new repository url to the LMS Web settings page: Settings, Plugins (additonal repositories at bottom of page), press apply
http://triodeapplets.googlecode.com/...sbtestrepo.xml (copy the link not text to make sure this forum does not give you a bad url)
4) Go to Settings, Advanced, Applet Installer on the player, unselect "Recommended Applets Only" and two new applets should appear in the list: Kernel Updater and USB Audio Ouput - install them one at a time (touch will reboot each time you install one)
5) Go to Settings, Advanced, Kernel Updater and select the kernel to install. Select one of the test kernels (See below), then read the warning text and select "Install". Touch should download a kernel and reboot, when it reboots it should include the text "USB Test Kernel" on the startup screen. If you do not see this then you are not running the test kernel and you should investigate why.
6) Ensure USB Dac is pluged in and turned on
7) Go to Setttings, Advanced, USB Audio Output and see if your USB Dac appears in the menu - if so select it (touch will reboot)
8) Touch should now be using the selected USB device for its audio output - to see the status return to the Settings, Advanced, USB Audio Output menu and select the device - this should show the current status of any playing stream
Important - before you update to the standard firmware again, you must reselect the Default output on the USB Audio Output menu otherwise the touch will continually reboot. [If you get to this point, press and hold the reset button to perform a factory reset and it should boot correctly]
Please report your findings here - interested in which dacs and what works/doesn't.
Update:
There are now three test kernels:
Test Kernel #1 - restricts the output rate to 44/48k sampling rates by overriding the rate at which the dac asks for output. It may allow async usb to work at these rates with a dac directly connected to your Touch. Known working devices:
- Audiolab M-DAC
- Audiolab 8200CDQ
Test Kernel #2 - this supports up to 96k sampling rate, but may require an external high speed usb hub between Touch and your dac. Known working devices:
- Audiolab M-DAC with external high speed hub
- Music Streamer II with external high speed hub
Test Kernel #3 - this includes most of the changes to the linux usbaudio driver to bring it up to date with ~April 2011. It may support a wider range of dacs.
Known working device:
- Audiolab M-DAC (USB audio class 1) with external high speed hub
- Audiolab M-DAC with external high speed hub
- Music Streamer II with external high speed hub
- Audiolab 8200CDQ with external high speed hub
- AudioEngine D1 with external high speed hub
Test Kernel #4 - as Kernel #3 but with more internal debugging messages (for expert users)
As reported by John S I've been looking at support for async usb dacs connected to the Usb port of Touch. I believe I've made some progress and have some changes to the touch firmware which I believe are worth sharing. At present this is really a proof of concept and I am looking for testers who have an async usb dac (usb 1.1 devices for the moment) and are willing to try some tests.
I've been testing these modifications with a usb 1 dac (Audiolab MDAC) - it will play at 44.1 and 48k sampling rates with my modified kernel. (The dac is capable of 96k, but to make it work with Touch at present I've modified the kernel to only support these lower rates)
The process for installing the updates is slightly involved, but should all be able to be done from the normal user interface. Instructions below:
1) Update to latest released Touch firmware
2) Perform factory reset to ensure any previous usb mods are removed
3) Add the following new repository url to the LMS Web settings page: Settings, Plugins (additonal repositories at bottom of page), press apply
http://triodeapplets.googlecode.com/...sbtestrepo.xml (copy the link not text to make sure this forum does not give you a bad url)
4) Go to Settings, Advanced, Applet Installer on the player, unselect "Recommended Applets Only" and two new applets should appear in the list: Kernel Updater and USB Audio Ouput - install them one at a time (touch will reboot each time you install one)
5) Go to Settings, Advanced, Kernel Updater and select the kernel to install. Select one of the test kernels (See below), then read the warning text and select "Install". Touch should download a kernel and reboot, when it reboots it should include the text "USB Test Kernel" on the startup screen. If you do not see this then you are not running the test kernel and you should investigate why.
6) Ensure USB Dac is pluged in and turned on
7) Go to Setttings, Advanced, USB Audio Output and see if your USB Dac appears in the menu - if so select it (touch will reboot)
8) Touch should now be using the selected USB device for its audio output - to see the status return to the Settings, Advanced, USB Audio Output menu and select the device - this should show the current status of any playing stream
Important - before you update to the standard firmware again, you must reselect the Default output on the USB Audio Output menu otherwise the touch will continually reboot. [If you get to this point, press and hold the reset button to perform a factory reset and it should boot correctly]
Please report your findings here - interested in which dacs and what works/doesn't.
Update:
There are now three test kernels:
Test Kernel #1 - restricts the output rate to 44/48k sampling rates by overriding the rate at which the dac asks for output. It may allow async usb to work at these rates with a dac directly connected to your Touch. Known working devices:
- Audiolab M-DAC
- Audiolab 8200CDQ
Test Kernel #2 - this supports up to 96k sampling rate, but may require an external high speed usb hub between Touch and your dac. Known working devices:
- Audiolab M-DAC with external high speed hub
- Music Streamer II with external high speed hub
Test Kernel #3 - this includes most of the changes to the linux usbaudio driver to bring it up to date with ~April 2011. It may support a wider range of dacs.
Known working device:
- Audiolab M-DAC (USB audio class 1) with external high speed hub
- Audiolab M-DAC with external high speed hub
- Music Streamer II with external high speed hub
- Audiolab 8200CDQ with external high speed hub
- AudioEngine D1 with external high speed hub
Test Kernel #4 - as Kernel #3 but with more internal debugging messages (for expert users)
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