I have two usb audio input devices that I'd like to mix and connect to
Jamulus, an application that uses jack (not pulseaudio). I'm trying to
find out if this is possible.
I'm running jack2 on a debian 10 system. There's one audio card (chip,
actually) that's listed as HDA Intel.
FYI The usb input devices are a Shure MV5 microphone and a Scarlett Solo
I can connect either of these devices to jack by specify one from
qjackctl setup: Settings -> Advanced -> Input device.
I don't see how to capture and mix the input from both devices. I
haven't found any documentation that explains how to do this or if it's
Hey, new subscriber here. I've been using JACK for several years but
know just enough about it to get it to work (usually). I've hit a couple
of issues with a new system build that have me stumped.
Specifics of the system: Ryzen 3700X; Asus Prime X470 Pro motherboard;
using (or at least attempting to use) the on-board audio, which is an
ALC1220. OS is Ubuntu 20.04 LTS; JACK is configured to run with realtime
Issue #1: Can't get any output from the digital (S/PDIF) port. I've made
sure S/PDIF is unmuted in alsamixer, and the S/PDIF output works fine
with PulseAudio. I've tried outputting to all of the system ports that
show in the JACK connection manager, and none of them produce any output
on the S/PDIF port.
Issue #2: If I run with the default number of output channels (6), JACK
stutters horribly with constant XRUNs. Already tried changing the
--period option; if I increase it JACK fails to start, and if I decrease
it the stuttering gets worse. Also tried changing --nperiods; increasing
it prevents JACK from starting. If I disable the last 2 channels (i.e.
run in 4 channel mode) the stuttering goes away.
I can live with #2 (don't really need the last 2 channels), but if I
can't get #1 resolved I'll be looking at a 3rd party soundcard (internal
or external) for this system.
Any thoughts/insights would be welcome.
Can you please put back link to downloads for windows and macos? Now
people get the wrong impression (at least one person have expressed
this opinion to me) that the downloads are gone because jack is
unstable on those two platforms, which they are not. (qjackctl is
though, but not jack itself).
Source code and binaries for linux/windows/osx here:
The Jack server sometimes crashes/freezes in ways which make users
restart the computer in order to use Jack again.
Users don't really have to restart the computer, but googling the
problem and finding a solution could take more time than restarting.
This is not very user friendly.
The problem exists on all platforms. It's not a bug in Jack per se,
it's how the program reacts when a client misbehave in certain ways.
This program kills Jack unconditionally. Executables for Linux, MacOS,
and Windows are provided. I strongly recommend that all programs using
Jack includes a program like this.
A better solution would be if Jack ran a watchdog, but it currently doesn't.
You are allowed to distribute this program any way you want. 
 Note that there might be copyright issues with the icon and the
quotes from the movie.
a few days ago, I ran into <
https://github.com/NixOS/nixpkgs/issues/96548>. I'm trying to cross-
compile JACK on x86-64 for ARMv7 and it fails. But I'm not 100% sure if
this is a NixOS packaging problem or if JACK can be cross compiled at
all. So please have a quick look at it and tell me if I should open an
issue on JACK itself instead.