Async USB Dac Experiments - testers wanted...

[diego]

Hi there Triode!

Good news: The TE8802L-DAC GETS detected with Windows Firmware on it and Kernel #9 on SBT.

"Bad" news: The behaviour is the same, as with EDO only (and its normal Kernel), and the Linux-Test-Firmware. That means:
- 44100/16 plays OK. When everything is just plugged in, cat... show values varying slightly around 44100. As soon as everything has plaied for some time, it stays on exactly 44100k.
- 48000/24 plays OK. cat... always shows 48002
- 96000/24 has two different situations:
>when all the gear is still cold: cat... shows values around 176004k. Sound is very aweful. Just noise, with some small idea of the music in the background.
>after playing for a while: cat... values shown switch between: 88004, 96002, 104002 Hz. Always arount these 3 values with plus minus 2Hz. Sound clicks very frequently music is recocnisable.

I send you the text files with all the cat... and dmesg outcomes by mail (as here, I can only post two attachments at one time)

To answer your other question: On Windows, the DAC with this firmware works OK with all frequencies up to 96K (not tested above) and word lengths of 16 and 24b.

(And just to explain: After a while of trying out, I found the reason for "DAC not detected" in my last tests: When rebooting, SBT/EDO seems to search for the last connected usb DAC. If the last usb dac is not detected, it stays on the "DAC not connected" screen (maybe you might modify the EDO so, that it goes by default to the screen, where the output can be selected).

So... now I am very keen to know the next step ! Thanks again for helping!

EDIT: Just got my I2S - connection - Kit to fit in between my USB-Interface and my DAC. Bypassing spdif between the DI and the DAC will allow me to use 192K. So after a bit of soldering and with some luck that I don't mess up something, I will be able to try 176.4 and 192khz. There is probably little chance that it works better than 96k, but who knows...

[diego]

Hi there fellows.

Good news for owners of a DAC using a TE8802L - USB-connection! It can now be connected over Asynchronous USB.

It works for audio-gd DACs. It might work for other TE8802L - Based DACs, too. In particular for instance, TEAC UD-H01.

PLEASE REPORT HERE, IF YOU GET YOUR DAC TO WORK, OR NOT.

And please say thank you to Triode. He worked on that many hours. I suppose he is British, and he was working even during the GB against Italy - game yesterday evening! Only the numerous tryouts and log file creations, that I did to assist Triode, took me hours, so developping must have been a huge task!

Disclaimer: This current version is still in Development Stage. However, I am able to play up to 24 bit / 192 khz - files with it. And it sounds great. But nobody can guarantee, that this will work for all users and any setups! All the modifications in this guide are at your own risk. They are not supported by any vendor, nor by myslef, nor by the developper Triode, nor by anybody else. They are in particular not supported by Logitech, audio-gd or Tenor (gfec). Any damage will be on your own risk! If you go further in this guide, you accept this condition!

However... For me, I can tell you, that it works. I have a Squeezebox Touch connected over USB to a audio-gd DI. However, be ready for a couple of hours of tryouts. My SBT got locked up several times. Luckily, I was able to reset everything to stock and standard every time, but this meant starting again the whole processe each time, too. If you are lucky and do it carefully, you may get your async cord working at the first try, however.

Here is the guide:

Prerequisites:

- I recommend, you use a DAC, that is externally powered, NOT USB-powered. The DAC may work over USB power, but I can not tell for sure. If your DAC has no separate power input, this usb - linear power - interface may help, and it will by the way enhance your sound quality: http://www.aqvox.de/usb-power_en.html ).
- Everything on the SBT and on the Logitech Media Server is updated to the latest versions and runs with default settings.
- Logitech Media Server must run on an external computer (or NAT), and Squeezebox Touch must be connected with this external server via Network. Wired ethernet lan is best, if possible. Provide a very good and robust connection, in particular if you want to stream bit-hungry 192k - files.


Now:
- connect the TE8802 - based - DAC to the Squeezebox Touch (SBT) over a good USB cable.
- Access the configuration screen of the Logitech Media Server over a web browser, go to the plugins - tab and add http://triodeapplets.googlecode.com/...sbtestrepo.xml as additional repository. (Hint: right-click on this link and choose "copy url" or "copy link location" or similar, to make sure, you get the whole URL to your clipboard). Choose as well, to show third party plugins.
- Go to the SBT, go to the applet installer (in settings, extended settings)
- Uncheck the tab that limits the choice to recommended apps
- Choose "Enhanced Digital Output" and install it. SBT will reboot, download a Kernel and reboot again.
- Play a song, it will not sound, but this is to make sure, your SBT is connected to the server
- Go again to the applet instller and install "Kernel Updater". SBT will reboot.
- Go to Kernel Updater (in settings, extended settings). Install Kernel #11. Wait until SBT reboots completely.
- Disconnect the power connection of the SBT and disconnect power from the DAC. Wait 10 seconds.
- Power on DAC and wait 10 seconds
- Power on the SBT and wait until it boots
- Go to the Audio-Settings and choose Digital Output. Choose your DAC over USB!
- The SBT will reboot. Then: Listen to the music

Recommendations: Choose "Screen disabled" screensaver while playing. If you use a volume regulated preamp after your DAC, lock volume to 100% on the SBT. Additional mods to the SBT, like TT3.0, will probably NOT work with default settings. Maybe they can work, but you will have to manually adjust priority settings and buffer settings, etc. You find lots of discussions about that on the audiophile threads. And none of those settings have been tried on Triode's Kernel 11 though. And altering those settings may make the SBT not to respond anymore. This can usually be resolved with a factory reset, but again, there is no guarantee. IMPORTANT: Please, discuss audio quality and audiophile mods only in the audiophile threads ( http://forums.slimdevices.com/showth...ty-impressions ). ***Do NOT discuss audio quality here***! THANKS!

To revert everything back to the original stage and factory defaults:
- Power on the SBT
- Hold down the little reset button on the back of the SBT just above the DC power plug for 10 seconds. This does the factory reset of the settings, but NOT of the installed Kernel !
- Let the SBT boot up to "Factory Settings".
- Go to the Software Updating Menu (in settings, extended settings)
- Force to "update" the Logitech Firmware
- Let the SBT boot up completely.
- Do another factory reset

Enjoy!

EDIT: I am not a programmer nor a technician, so this is what I understood... correct me if something is not accurate or if I don't use the correct terms. The Test Kernel #11 seems to correct a couple of bugs that originate from the TE8802L Chip or its firmware. It corrects some obviously false frequency feedback messages and replaces them with estimated values. However, this Kernel is "custom tailored" to my configuration in order to test, if in principle, the whole thing may work. This test was successful so far. However, these Tenor-bugs must eventually be corrected differently on different setups. For instance, two equal looking TE8802L - input - boards may have slightly different crystal clocks that make a difference in the timing. Therefore Triode now created Kernel #12, and he says, this one is more generic. However, try for yourself, what works...

EDIT:

Try tne new Kernel #12 first. It corrects more possible firmware-bugs. If it does not work, its worth to try Kernel #11, too.

AND DONT FORGET, please:
Post your findings here. Among everything else that seems importante, please give us an exact indication about the DAC you use and the frequency of the music files you tested.

[warpeon]

This worked on my Audio-GD V2!! Thank you so much!

[Triode]

Please be aware that kernel #11 will only work with usb2 devices and is specifically designed for the Tenor 8802l device.

It appears that the Tenor device corrupts the feedback messages it sends to the linux host. This firmware contains some code to work around the specific corruption seen on diego's device. This may work for other users, but its possible that we need to make the workaround more generic to work for other instances of the Tenor device.

[diego]

Please be aware that kernel #11 will only work with usb2 devices and is specifically designed for the Tenor 8802l device.

It appears that the Tenor device corrupts the feedback messages it sends to the linux host. This firmware contains some code to work around the specific corruption seen on diego's device. This may work for other users, but its possible that we need to make the workaround more generic to work for other instances of the Tenor device.

Anyway it is a good start. I think this will put pressure on the firmware developers at Tenor, and this is fine. They now know that it is known that their firmware (or even hardware?) has flaws. So let's hope that this will motivate them to bring out a stable set of firmware and drivers. Manufacturers will obviously think twice, if they prefer the Tenor chip or another one, that may be more expensive or less advanced in some aspects, but more robust and therefore causing less problems to clients. As seen on the audio-gd website right now, they are calling for reports about issues... so it seems, that they have been under pressure to start selling their chip in a rather beta stage...

[diego]

To celebrate its working, I just got myself Beethoven's 5th in 24/96 from here: http://www.qobuz.com/album/west-east.../0002894783821 . F... I've never been so close to the stage, in my living... (sorry, had to be said ;-) )

[Triode]

Its worth saying that I would like to hear from other SBT users with Tenor devices as the work around for diego may need changing for other devices. I would like to get some more test data and would ask that anyone willing to do so posts here and we can ask you to try one of the test kernels to get us some more debug messages.

I've also written to Tenor about this.

[geg]

Hello All,

I have an audio-gd NFB 9.2 with TE8802L that is working connected trough usb. I have played 16/44 24/96 and 24/192 Flac files with great results. I followed the guide from Diego and I had also to increase the size of the buffer to avoid strange noises.

Thank you to Triode and Diego.

Triode are you going to implement it on the next version of EDO (0.8)?

[warpeon]

What is kernel #12?

[Triode]

What is kernel #12?

Kernel #12 is intended for tenor 8802l devices. It tries to correct slightly more cases than kernel #11 for corrupted feedback packets which the tenor device seems to produce. If you have a tenor 8802l based device I would be interested in feedback on kernel #12.