SSL Big6 routing works in Ubuntu Studio but not AV Linux

[Bransby]

Hi

Really strange problem, I'm dual booting Ubuntu Studio 22.10 and AV Linux 21.2.1. I've got an SSL Big6 USB interface running into Ardour 7.4 on both systems. I'm trying to sum a mix, the SSL Big6 allows a return from the main output on channels 15+16 so to sum a mix I've created create a stereo track in Ardour with inputs as 15+16.

I'm opening the same Ardour project in both Ubuntu Studio and AV Linux, I can play and route all tracks in the usual way on both systems but on the AV Linux system I cannot get audio in from inputs 15+16. On Ubuntu Studio I can see the relevant connections in Carla and on AV Linux in the Jack Graph view I can see the connections are exactly the same Channels 15+15 from the Big6 are routed to this stereo track. On Ubuntu Studio I can get the audio onto the track from inputs 15+16, in AV Linux I get nothing, the connections are all setup exactly the same.

Same hardware, same Ardour project the only difference is Ubuntu Studio and AV Linux, I'm at a loss to understand why I can't get the audio in from 15+16 in AV Linux. Other inputs in AV Linux are working fine, I've tracked most of this project in AV Linux.

I Moved to AV Linux as I found it to be far more stable than Ubuntu Studio where Plasma crashes on me all the time, it'd be a real shame if I have to move away from AV Linux because of this issue. Anyone got any ideas?

Thanks

Bransby

[tseaver]

@Bransby

I Moved to AV Linux as I found it to be far more stable than Ubuntu Studio where Plasma crashes on me all the time, it'd be a real shame if I have to move away from AV Linux because of this issue. Anyone got any ideas?

• What kernel versions are running on each bootable OS?
• You state that you have AV Linux 21.2.1 installed. Can you try running from a USB stick for AV Linux 21.3 instead? It will get you a newer kernel, plus other tweaks / fixes to the audio setup. I've just recently switched to 21.3, and find it a big improvement.

[Bransby]

AV Linux is running 6.0.0-10.1-liquorix-amd64
Ubuntu Studio is running 5.19.0-1024-lowlatency

OK, I’ve updated to 21.3 Wildflower but it looks like the same kernel version and the issue persists. Given it works on the older kernel in Ubuntu Studio do you think it’s worth rolling back the kernel version in AV Linux to match Ubuntu? I’m guessing not because it’s a specially customised kernel on AV Linux and I’m guessing I’d create more problems than I’d solve trying to roll it back?

[bluebell]

Maybe it's not the kernel but ALSA's stored mixer settings.

Start alsamixer and see if channels 15 and 16 are muted.

[Bransby]

Hi bluebell, I've checked Alsamixer and all appears fine, all settings apprear the same across both distros.

[Bransby]

On the Ardour forum someone suggested trying different kernels, to that end I tried 5.19 and 6.4 on AV Linux but still get the same issue so at this point I'm assuming it's not a kernel issue.

It feels like a Jack issue but I can’t see any difference in the setups between the two.

The only setting I can see that feels like it might impact what I’m trying to do is “Self connect mode”, but on both systems it’s set to “Don’t restrict self connect requests (default)”.

[khz]

With a Debian Bullseye/Bookworm the BigSix works 100%. I have installed the latest firmware (SSL Audio Firmware Updater for SSL 2/2+ and BiG SiX: https://www.solidstatelogic.com/product ... ddownloads). Do you have that too?

[khz]

Yes, ideally. Where I am convinced by bugfixes, stability and possibly more functions - depending on the update process! - often convince. Some hardware instruments grow (firmware update) nowadays also at the user's home. Also there: Whereby bugfixes, stability and possibly more functions - !depending on the update process! - often convince me.
The first devices also had problems with humming(?) at the microphone with phantom power on, which can be fixed by their support. Current devices have no more problem. Unfortunate? Yes. Accommodating (on the part of the company): Yes.
Whether the firmware update necessarily fixes the problem of @Bransby I may doubt. I also think that it rather has something to do with - possibly - the respective kernel version. Or ...

[Bransby]

Hi All

Thanks for the replies. Re updating the firmware, I'm a bit reluctant to do that at the moment because (a) as someone else has pointed out, you spend a fair bit of cash on an interface you don't really want to be flashing new firmware straight away and (b) it works perfectly under Ubuntu Studio.

The main reason I moved away from Ubuntu Studio was that I was having a lot of problems with KDE Plasma and I wanted to try AV Linux.

Whilst I'm still keen to resolve this issue with AV Linux, I've moved to Cinnamon desktop on Ubuntu Studio now and everything is working perfectly.

So yes, I get your point about updating firmware but if the interface is working perfectly on one distro and not on the other it does feel like there's something I'm missing in AV Linux somewhere and that's what I'm keen to work out.

Thanks

Bransby

[khz]

The firmware update has nothing to do with your problem, it was just a hint. Before the mixer worked 100%, after the firmware update also.

Whether the firmware update necessarily fixes the problem of @Bransby I may doubt. I also think that it rather has something to do with - possibly - the respective kernel version. Or ...

What the problem is related to I can not tell you exactly, maybe someone else can help. The developer of AV Linux, @GMaq, is also here. Maybe he has an idea.

[GMaq]

What the problem is related to I can not tell you exactly, maybe someone else can help. The developer of AV Linux, @GMaq, is also here. Maybe he has an idea.

I did answer on the Ardour forum to try other Liquorix Kernels which did not work, I don't have this interface to test but I do not know of anything specific to AV Linux that would cause this, JACK, Qjackctl, PulseAudio are all the Distribution Packages and not customized. Generally Liquorix kernels give excellent performance with up to date ALSA Drivers.

If it were me I wouldn't be using an interface with JACK in Ardour, I would be using Ardour and the USB Interface direct with the Ardour ALSA Backend..

[Bransby]

If it were me I wouldn't be using an interface with JACK in Ardour, I would be using Ardour and the USB Interface direct with the Ardour ALSA Backend..

Hey GMaq, I've never tried that to be honest, have always just used Jack with Ardour, but I'll give it a go and see what happens.

Thanks

[Bransby]

testing the above

[Bransby]

OK so I've tried using ALSA back end rather than Jack in both Ubuntu Studio and AV Linux the good news (for me as I've never tried it before) is that ALSA works fine and Ardour can see all the connections to and from the Big6.

The bad news is that the same problem persists in AV Linux. It can see the inbound connections from channels 15&16 but cannot receive a signal from them. Again, same project running on Ubuntu Studio can see the signal from channels 15&16. I also tried creating a brand new project to double check and it's the same issue. Both systems can see all relevant ins and outs, I can make the required connections in Ardour. In Ubuntu Studio the signal comes in and I can record it, in AV Linux it doesn't.

So it doesn't appear to be a Jack issue, it wouldn't seem to be a kernel issue given that it happens under 3 different kernels on AV Linux. What else can I try?

[asbak]

Compare the version of ALSA and compile/install a later version if the version on AV Linux is older than on Ubuntu.
Same with jack.