Howto: Jack-Rack as a guitar effect-processor (with LASH)

[studio32]

**About:

This tutorial aims to describe how you can use Jack-Rack as a effect processor for your electric guitar.

** Before:
- you should have installed and set up right jack by qjackctl
- you should be able to hear 'realtime' and clean guitar sound out of your speakers.
- I think you need a sort of preamp or mixer to get guitar sound. I do use just a simple Boss distortion pedal for it and that works :)
- you should have jack-rack and LASH (linux audio session handler) (optional) installed.
- You have downloaded (and unpacked) some effect for jack-rack:
http://offog.org/stuff/racks/


1) Start jack

Code: Select all

qjackctl

2) Start jack-rack

Code: Select all

jack-rack

3) load a jack-rack effect


Open > browse to and load jack-rack effect (I loaded a file called: guitar_amp.rack)



4) Connect jack-rack

- Click on "Connect" in qjackctl. You'll see "system" and "system" plus 'ams' and 'ams' . Left is hardware, right is software. You should see capture on the left, and playback on the right. playback_1 == left speaker and playback_2 == right speaker, capture_1 == mic port and capture_2 == nothing/built-in laptop mic.

- For example, you'd want to connect capture_1 to playback_1 and 2. Highlight capture_1 and highlight the "system" on the right panel. Drag your cursor from the former to the latter.

*** BE CAREFULL: Always put your sound down when connecting. I had once a awful and very very load beep through my speakers when I first tried to connect something! Remember ears are important for musicians!***

Connect things now like this:



5) You should here a 'effected guitar sound' now :)

-------------------------------------------------------------------------------------

To make things a bit easier and faster for repeating sessions.


6) qjackctl patchbay

You can save the connections setup via 'Patchbay' in qjackctl, so you can load it easier the next time you want to use Jack-rack.

Patchbay > new > 'Create patchbay definition as a snapshot of all actual client connections? >> ok* > save.
The next time you can load this setup in patchbay easily.

* It is recommended to choose no and make a patchbay manually like it is explained in the patchbay howto http://www.rncbc.org/drupal/node/76





(! You can also use (the latest) patchage with lash_support: http://wiki.drobilla.net/Patchage )





THE VERY QUICK AND EASY WAY, using LASH

Load the jack-rack setting by LASH

7)When things are running, you can start LASH

Code: Select all

lash_panel

The project which is currently running (and is suported by lash) will be automatically be displayed in the lash_panel (that's my experience at least)...



8)Save the project

> save project





The next time you want to use Jack-rack with the same effect:

1) start qjackctl

2) start LASH

Code: Select all

lash_panel

3) open saved project

4) open jack-rack

Code: Select all

jack-rack

The saved settings and setup will come up now! :)




Using a script

You also can start the describes steps by a little script

1) open a editor like gedit or kate

2) copy paste:

Code: Select all

#!/bin/sh 
 qjackctl & 
 sleep 2
 lash_panel &
 sleep 10
 jack-rack & 
 exit

(sleep will give you some time to start and load the needed things)
3) save file as name.sh

4) Now you must make the script executable (I think as root):

Code: Select all

chmod +x name.sh

5) run the script



Enjoy!


feedback!?: did you find this tutorial usefull or have comments on the content. I like to hear it! Further questions or problem solving could be better take place in the other forum parts....

Further readings and reference:
- howo using AMS as effect processor: http://linuxmusicians.com/viewtopic.php?t=123
- Jack-rack: http://jack-rack.sourceforge.net/
- http://www.rncbc.org/drupal/node/76 (about qjackctl: patchbay and conections)
- LASH (linux audio session handler): http://lash.nongnu.org/
- More guitar processors: www.linux-sound.org >> Effects Processors
- LADSPA (Linux Audio Developers Simple Plugin): http://en.wikipedia.org/wiki/LADSPA
- CAPS (The CAPS Audio Plugin Suite): http://quitte.de/dsp/caps.html

[commongrackle]

Thanks for the tutorial!!!
I have everything working.

Can jack-rack or lash be configured to load a project automatically without any keyboard/mouse input.

I am building a virtual organ with touchscreens. Jack and jOrgan will load at startup but I wish to use jack-rack with some sound processors. Everything has to load without a mouse or keyboard.

Thanks
Peter

[raboof]

Can jack-rack or lash be configured to load a project automatically without any keyboard/mouse input.

You want to run the script on startup, right? That should be totally possible.

I am building a virtual organ with touchscreens. Jack and jOrgan will load at startup but I wish to use jack-rack with some sound processors. Everything has to load without a mouse or keyboard.

Interesting. I assume you're using X.org? You could include the script in your ~/.Xsession along with the windowmanager of your choice - but it's slightly distribution-dependent how you should tell X.org to load that script. Which distro are you using as a basis?

[commongrackle]

Hi
Let me clarify the set-up. Up to now I've just been a computer user and never 'dug into' the OS. I'm using Ubuntu 9.04 with a M-Audio Delta1010LT sound card.
I'm building a headless organ - no computer keyboard or mouse. There are 3 manuals and a pedalboard and a touchscreen monitor on each side - like a pipe organ.
I have a separate soundfont for each division. With Jack I've got each manual and pedalboard going through a separate amp and speakers. I simply added 'Qjackctl' and 'jOrgan.jar' to the start menu and the system boots up into the organ programme perfectly.
Then I used jack-rack and added reverb to each channel in the jack patch-bay. I can add jack-rack to the start menu and it loads 'jack then jack-rack then jOrgan'. The problem is I need jack-rack to load with my reverb setup since I don't want a mouse or computer keyboard. I can save the project. How do I have it load when jack-rack starts? Will lash do this?

BTW jOrgan is an extremely flexible and ever evolving midi relay that can be used to control other sound engines (including real organ pipes).

Thanks
Peter

[transmogrifox]

Pretty cool organ setup.

If you're using it in a regular desktop environment, then surely you can make a "launcher" icon to place on the panel to execute the script suggested above. This way you touch the icon when you wish to launch this application.

Else, you can place the script in your startup applications.
//
First of all, nice post. I never realized this large repository of racks was available. This makes jack-rack much faster to get started and rolling, and also to discover some of the plugins .

I started my linux guitar journey with jack-rack, then discovered rakarrack (rakarrack.sourceforge.net). I liked it so much I became a dev on the team The biggest sellers to me are how many parameters are available to adjust, fx initial presets, and the phenominal MIDI integration and tap tempo (little for which I can take credit...I only work within this wonderful structure). Recent development has seen the addition of many interesting effects including a convolution engine with current work on an RT-friendly vocoder (guitar talker w/ aux mic input). The interesting stuff is recent, so requires compiling from source (git repository)...so if you're not a "sourceror", then keep your eyes open for more recent packages tumbling down your distribution's food chain. I suspect Ubuntu users will have the easiest times getting up-to-date packages through the PPA's.

The beauty of jack and the FOSS audio production environment is, Guitarix, Jack-rack, rakarrack and others can all be used together as a feature-rich guitar experience, taking advantage of the strengths in each one...and don't forget about the awexome Calf Audio Plugin Pack. Calf is really high quality