No JACK output to external soundcards

[AdamCWB]

I'm new to Linux music-making (and currently feeling a bit frustrated

I'm using Ardour 5.3 with Fedora 24. I've been able to record with both a Focursite Scarlett 18i8, and with a Focusrite Saffire Pro26 (using ffado 2٫2, though it doesn't officially support the Pro26). So far, all great.

However, I can't get any playback via either audio interface when selected in QjackCTL. If I select the internal interface, it plays fine on my internal speakers. So - as far as I can tell, the problem is between JACK and the interfaces.

When changing interfaces, all I've adjusted is 'driver' and 'interface' in the Parameters tab and 'input device' and 'output device' in the advanced tab.


I can post any diagnostic output or further info, but I'm not sure what is relevant. My Googling hasn't turned up anything useful yet, so any help at all would be very gratefully received!

[Pablo]

When you use jack with the focusrite interface for recording and at the same time, want to use the onboard card for playback, you need to launch a program called zita-j2a after starting jack. It is a command line program. First, you need to know the short name of the audio cards. It is between square brackets in the output of the following informative command:

cat /proc/asound/cards

Assuming your internal card is called PCH (just a guess), the command you need is:

zita-j2a -dhw:PCH

After this, you have to connect the ardour master (or whatever) to zita-j2a playback ports (which of course is the onboard audio card).

As for the other issue, that the Scarlett doesn't work for playback, you should diagnose it first without jack. Does it produce sound at all, via the desktop audio configuration? Maybe there is a control for playback that is muted. Check alsamixer.

Cheers, Pablo

[AdamCWB]

Hi Pablo,

Thanks for your reply, and sorry for my slow response. I'll look into zita-j2a. But at the moment, it's just the lack of any sound output that's the problem - not just recording/playing.

It doesn't produce any sound at the moment. In the Gnome desktop settings it shows up as 'Multitrack Output - Scarlett 18i8' and doesn't provide any settings (all the sliders are greyed out). But it gives no option for stereo out. There is no audible output from Test Speakers.

I've checked alsamixer. I find some of it confusing (as I said, I'm new to all this). But I can't see anything muted. I've not tried turning off Pulse Audio, but there doesn't seem to be a simple way of doing so, and I don't know if it would make any difference.

I've tried the same settings with the same audio interface & cables on a MacBook Pro running Fedora 23, and it works fine.

Any further thoughts would be very gratefully received.

[Pablo]

Sorry, I can't help. I suggest you should open a new thread with a proper subject mentioning the Scarlett 18i8 in the "Hardware Support & Discussion --> Computer Related Hardware" board