Ultralite AVB

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bluebell
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Re: Ultralite AVB

Post by bluebell »

I am no great programmer but I see that linux-5.8-rc6 has added support for implicit feedback.

I try to adapt drumfix's patches to that kernel to see if there is some improvement, but don't count on me.

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Re: Ultralite AVB

Post by bluebell »

OK, the patch could be simplified and on my machine I get some sound out of the Ultralite AVB. It's the older one without ESS chips but with the most recent firmware.

The patch is for linux-5.8-rc6.

Test && enjoy.
drumbell_avb-patch_for_linux_5.8.rc6.txt
(950 Bytes) Downloaded 110 times

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Re: Ultralite AVB

Post by bluebell »

No big improvement: When I change the buffer size with jack_bufsize I get a modulo-8 output channel hop.

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Re: Ultralite AVB

Post by bluebell »

At least the sound quality is ok while running jackd for more than 10 hours.

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Re: Ultralite AVB

Post by root2 »

bluebell wrote: Sat Jul 25, 2020 10:24 pm OK, the patch could be simplified and on my machine I get some sound out of the Ultralite AVB. It's the older one without ESS chips but with the most recent firmware.

The patch is for linux-5.8-rc6.

Test && enjoy.

drumbell_avb-patch_for_linux_5.8.rc6.txt
I just compiled linux-5.8-rc6 with your patch. I will test with my ESS Version
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Re: Ultralite AVB

Post by root2 »

Seems to work fine for now, but channel hopping is still a problem
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Re: Ultralite AVB

Post by bluebell »

root2 wrote: Mon Jul 27, 2020 11:41 am Seems to work fine for now, but channel hopping is still a problem
I am not sure if the channelhopping is an ALSA or a jackd problem. Since restarting jackd helps, it may be a jackd problem. Unfortunately I got no helpful response from the jackd mailing list.

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Re: Ultralite AVB

Post by mxxxl »

I had no time yet to compile a new kernel with the latest patch by bluebell but did some further testing wih alsa and pulseaudio without jack.

Without jack I experience similar issues fritz_distran mentioned in his post. Playing a two channel file with mplayer through pulseaudio and alsa causes all channels up to channel 8, exept channel 6 to carry the singal. It seems rather random.
channels.png
channels.png (63.76 KiB) Viewed 4201 times
When playing an 8 channel file with mplayer it seems to work as expected.
I tried to replicate the same with pure data, e.g. sending a signal to all eight channels one after another. This time ist worked flawlessly and without channel hopping, but i noticed that in the moment of turning off the DSP in pure data the singal appears 8 Channels avove again for a fraction of a second before it is finally turned off.

When using jack theese problems seem not to show up, and I oddly did not even experience channel hopping today.
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Re: Ultralite AVB

Post by root2 »

bluebell wrote: Mon Jul 27, 2020 4:20 pm
root2 wrote: Mon Jul 27, 2020 11:41 am Seems to work fine for now, but channel hopping is still a problem
I am not sure if the channelhopping is an ALSA or a jackd problem. Since restarting jackd helps, it may be a jackd problem. Unfortunately I got no helpful response from the jackd mailing list.
I experienced channelhopping with both, ALSA and Jack...
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Re: Ultralite AVB

Post by bluebell »

I posted the problem on the alsa-devel mailing list. I want to get the issue fixed. The Ultralite AVB is such a cool interface.

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Re: Ultralite AVB

Post by KREAM »

root2 wrote: Mon Jul 27, 2020 10:17 pm
bluebell wrote: Mon Jul 27, 2020 4:20 pm
root2 wrote: Mon Jul 27, 2020 11:41 am Seems to work fine for now, but channel hopping is still a problem
I am not sure if the channelhopping is an ALSA or a jackd problem. Since restarting jackd helps, it may be a jackd problem. Unfortunately I got no helpful response from the jackd mailing list.
I experienced channelhopping with both, ALSA and Jack...
I have a MOTU 1248 and have the same issues since the TouchControl firmware update. I wonder if it's related to the addition of the "host offset" buffer setting. I agree that it's probably an ALSA or PulseAudio problem because it also happens in "plain" distros like Ubuntu, Manjaro, and Neon that aren't using JACK at all. I'd love to see this get fixed because I haven't been able to run Linux in literally years because of this problem.
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Re: Ultralite AVB

Post by bluebell »

KREAM wrote: Wed Jul 29, 2020 11:15 am
I have a MOTU 1248 and have the same issues since the TouchControl firmware update. I wonder if it's related to the addition of the "host offset" buffer setting. I agree that it's probably an ALSA or PulseAudio problem because it also happens in "plain" distros like Ubuntu, Manjaro, and Neon that aren't using JACK at all. I'd love to see this get fixed because I haven't been able to run Linux in literally years because of this problem.
If you have a fast channel hopping every couple of seconds then I guess it's because of the use of implicit feedback endpoints in the USB conversation with recent firmware.

A recent kernel and my patch can probably help a lot.

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Re: Ultralite AVB

Post by t-legiaw »

Unfortunately, the same problems here in the home office, with a Motu 624.

So far I have tried everything imaginable ...
  • a newer kernel (upto the newest 5_8 kernel) and also applied the latest patches ( Drumfix, Bluebell, DrumBell)
  • various alternative configuration settings (Alsa, PulseAudio, Jack)
  • downgrades to older versions of the firmware
  • UAC mode vs USB2 mode
Sometimes it is stable for a few days. Then again nothing works at all. The whole thing is very frustrating.

In an earlier article, the AVB interface was mentioned as an alternative. But even that looks anything but easy.

But there is another interface that seems not to have been mentioned at all, namely ADAT.

Here (https://www.minidsp.com/products/usb-au ... reamer-box)I found a small ADAT-to-USB converter box. Not overly expensive (about 100EUR). Since the manufacturer explicitly mentions alsa compatibility I have ordered this now and will give a feedback here when the box has arrived.
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Re: Ultralite AVB

Post by bluebell »

t-legiaw wrote: Mon Aug 10, 2020 12:42 pm Here (https://www.minidsp.com/products/usb-au ... reamer-box)I found a small ADAT-to-USB converter box. Not overly expensive (about 100EUR). Since the manufacturer explicitly mentions alsa compatibility I have ordered this now and will give a feedback here when the box has arrived.
Interesting. If it works in both directions it'll be worth a try.

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Re: Ultralite AVB

Post by root2 »

bluebell wrote: Mon Aug 10, 2020 2:32 pm
t-legiaw wrote: Mon Aug 10, 2020 12:42 pm Here (https://www.minidsp.com/products/usb-au ... reamer-box)I found a small ADAT-to-USB converter box. Not overly expensive (about 100EUR). Since the manufacturer explicitly mentions alsa compatibility I have ordered this now and will give a feedback here when the box has arrived.
Interesting. If it works in both directions it'll be worth a try.
It seems like it does:
The USBStreamer utilizes high speed USB2.0 along with the Audio Class 2.0 implementation to simultaneously provide up to 8channels of playback along with 8channel of recording over the ADAT standard
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