SSL Big6 Routing problem in ubuntu studio

[Bransby (Bransbymw)]

I believe this is a recurrence of a problem I first posted about here

Big6 routing works in Ubuntu Studio but not AV Linux

Hi, apologies in advance as I don’t believe this is a problem with Ardour but I have a very strange issue with routing my SSL Big6 into Ardour. 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 …

I’m using the SSL Big6 mixer/usb interface, ardour 8.12, ubuntu studio 25.04,
kernel version 6.14.0-28-generic (64-bit)

Under previous versions of ubuntu studio using Jack I was able to route the main output of the SSL Big6 from channels 15&16 on the mixer back into Ardour by selecting inputs 15&16 in Ardour - this is how I was able to print back into Ardour from the mixer. Now, although all routing appears normal and correct in Ardour no signal comes back in from the mixer. The mixer gives the option of routing the main output to channels 13 and 14 instead of 15 and 16, that doesn’t work either, I can’t get the main output of the mixer back into Ardour despite all routing appearing correct.

In the post linked above it appeared to be an issue with AV Linux, the problem was exactly the same, I can make all the routing connections but no signal comes in. Back then I was dual running AV Linux and an older version of Ubuntu Studio, the same project with the same routing worked on the older Ubuntu Studio, but not under AV Linux. Now I’m experiencing exactly the same issue with Ubuntu Studio, the routing all appears correct but nothing comes in from the main outputs of the mixer.

I’ve also tried switching to ALSA in Ardour and the same problem occurs, so I don’t think it’s an Ardour issue (apologies for posting here!) - it seems to be something to do with how ubuntu’s seeing or accessing the interface - I can record from it with no problems, it seems specifically related to trying to route the main outputs of the mixer back into Ardour.

Any ideas?

[Bransby (Bransbymw)]

Finally found the cause of this, I discovered in QASMixer that, for whatever reason, inputs 13-16 on the Big6 were muted by default, I’ve unmuted them an everything is working again as intended.