[LAU] Soundcraft MTK22 + jack: first 16 channels silent

[Atte]

On Fri, 16 Mar 2018 11:57:13 -0400
Joe Hartley <jh at brainiac.com> wrote:

> On Fri, 16 Mar 2018 10:58:36 +0100
> Atte <atte at youmail.dk> wrote:
> 
> > I have two computers, a laptop and a desktop box running identical setups: Debian stretch with 4.12.0-14.3-liquorix-686-pae kernel and jack version 1.9.10.
> > 
> > On the laptop my mtk22 works perfectly, on the box the first 16 channels are silent.
> 
> I don't understand what you mean by 'silent' here. 

Ok sorry for being unclear!

Let's say I have input going on all 22 channels. By "silent" I mean that if I route any of the first 16 tracks in qjackctl to a recording program (while testing I mostly used mhwaveedit) there's no input in the recording program, it's like they are muted. Input on channel 17-24 (23-24 are master) pass through just fine. Basically it behaves as if I didn't route those first 16 channels in qjackctl. Makes sense?

Just to make it clear! I can hear the audio, though my monitors connected to MST out.

> If you are taking an input signal and seeing it at your DAW but not hearing
> output, check that the USB Return buttons on each channel are not pressed.

They are not pressed. I've been testing this back and forth between the laptop (works perfectly) and box (not working) for hours yesterday (and when I installed stretch in august and occationally when I got sufficiently annoyed time times in between) and the mixer is not touched, just move the USB cable from box to laptop, laptop works, box doesn't.

> When pushed in, the mixer is expecting those channels to take their input
> from the computer, which allows the use of plugins in a DAW to be used to
> effect the 'live' output from the mixer.

I'm aware of that...
 
> You refer to "the first 16 channels".  This raises the important question
> of what happens on channels 17/18.

They work as expected. Whatever I connect to input 17 can be routed in qjackctl from capture_17 and the program it gets routed to "hears" the audio (again it's like audio on capture 1-16 are just muted.

There's something to that number 16 that smells like software...

> What are these upper channels (17-22) doing differently than the others

Passing the audio through capture 17-22

> It could be a JACK routing issue with some config persisting from something
> else.  Have you looked at the routing table, both at the JACK and at the DAW
> levels?

Could you elaborate on "routing table"? I left any DAW out of these tests (obviously I discovered the problem in my DAW), the problem is before that. The two pieces of software I used for these tests are mhwaveedit and renoise, manually connected in qjackctl.

Cheers
-- 
Atte

http://atte.dk   http://a773.dk