Ubuntu Studio - QjackCtl and Pulseaudio for IDJC

Configuration guide for using IDJC for broadcasting. Create 2 audio inputs from Pulseaudio to JACK for IDJC VOIP and Aux

QjackCtl & Pulseaudio for Internet DJ Console

Confirmed working 15 November 2017 on Ubuntu Studio 15.10 64-bit

Other Distributions should have packages available for similar setup:
pulseaudio – v6.0 or higher required for additional Aux connection; earlier versions only support one Pulseaudio link to JACK
pulseaudio-jack – required for creating Pulseaudio connections to JACK
pavucontrol – (Pulseaudio Volume Control) preferred method to control Pulseaudio levels and preferences
jack2 – works with D-Bus and allows Pulseaudio and JACK to share an audio device

QjackCtl Setup

Interface: select your sound device for JACK

Frames/Period: 1024 is safe working value for most sound devices. Lower value will reduce latency delay but may increase x-run errors

Sample Rate: 48000Hz is native JACK rate, but 44100Hz may work better on some hardware

Periods/Buffer: Usually 2 is fine for built-in sound devices or 3 for USB devices

Other tabs – Advanced; Options and Display – not covered here. Default settings should not be a problem

Enable D-Bus Interface: enabled

Enable JACK D-Bus Interface: enabled

D-Bus allows Jack to share an audio device with Pulseaudio
If Jack cannot be started with D-Bus, additional setup work will be required

Save settings when done with button on Settings tab

Start JACK in QjackCtl

Jack input and output ports will be loaded with default connections:

Add Pulseaudio Aux connection to JACK

Run this terminal command:

pactl load-module module-jack-sink client_name = Aux_In

Test audio connections from sources in Pulseaudo
Playback from Pulseaudio to JACK can be routed to either Pulseaudio JACK Sink or Aux_In

Clear JACK connections before starting IDJC

Use “Disconnect All” button in Qjackctl Connections window

qjackctl no connections

Leaving any connections is likely to cause echo/feedback problems

Start IDJC

Connections from PulseAudio JACK Sink and Aux_In to IDJC, and IDJC to PulseAudio JACK Source may require manual connection

QjackCtl Connections window can be expanded to check or modify connections

IDJC menu Jack Ports section can also be used to check or modify connections

There is also additional package Patchage, with better graphical view of JACK connections, included in Ubuntu Studio

Use IDJC red or green phone buttons to hear a call. Only green (on-air) phone will show on stream level meters.

Sound to Aux channels will show on IDJC Ch3 and Ch4 input meters, and on stream level meters if IDJC Aux button is on

This is simple method to test and setup IDJC

Another article soon to configure start of JACK and IDJC automatically for regular use

thanks to

jimmy daz3d, timfromtang, freemanjack, muddymuddymudman, fairport and everyone at Linux Migration Group


wow nik

lovely job.

meant to get back to have a look but been so bloody busy just forgot.

i like it great work man


Thanks for advising broken link to my website Jimmy

Replaced wget command for simpler download link to local patchbay config file

Still want to encourage command line use, but not at expense of simplicity