Setting up USB-Audio-Interface + Guitarix to practice guitar

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baxbear
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Setting up USB-Audio-Interface + Guitarix to practice guitar

Post by baxbear »

Greetings Community,

I would like to create a certain setup. I am running Archlinux on a Lenovo P15 Gen. 1 and bought an used Roland Rubix22 Usb Audio Interface in which I would like to put in my guitar setup an amp simulator like Guitarix and then hear the music I play on my guitar from the speakers of my notebook or through some headphones.

I installed the pro-audio package group which includes all necessary packages like jackd, guitarix and a lot more stuff (I provide the link to the package group if you are not sure whether I have a certain package. I replaced jackd with jackd2 since most tutorials I found have been written with jackd2 in mind. (And 2 sounds better than 1)

I also have qjackctl installed. In qjackctl I chose as Output Device: hw:PCH and as Input Device hw:Rubix22,0. Channels and Latency I/O is set to default. (My current latency is at 42.7msec, which is something that should maybe fixed later on first I would like to connect my guitar to the 1L instrumentcable port of my USB Audio Device with enabled Hi-Z and here something on my speakers when I pick a string. In most of the tutorials peoples started to connect lines in the Graph or Patchbay window (not sure) I didn't since first of all no devices will be shown there and I also would have no clue what I am actually doing.
I just started guitarix afterwards which prints an error message:

Code: Select all

system init *** mlocalall failed:
system init *** failed to lock memory: Cannot allocate memory
system init *** failed to lock memory: Cannot allocate memory
PitchTracker *** error creating realtime thread - tuner not started
but doesn't crash. So I connected my guitar and noticed - I have no sound. I started experimenting with jack ports in Guitarix but it did not lead to a change. I also read that sometimes there are problems with running jackd and pulseaudio. But I would like to run both to e.g. play along to a youtube video etc. maybe we find a solution.

Primary Goals
  • create a setup that takes my guitar sound as input and outputs it to my speaker
Bonus:
  • reduce latency
  • understand how to setup sound settings and amp simulations in guitarix to create some decent sound
Please tell me which precise system information are necessary and the commands that provide those.
baxbear
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Posts: 3
Joined: Sun Dec 27, 2020 10:33 pm

Re: Setting up USB-Audio-Interface + Guitarix to practice guitar

Post by baxbear »

I found that I also have cadence installed. I started it stopped the jackd server with it and setup the same as I intended to setup in qjackctl. Afterwards I forced a restart in cadence. Then I started guitarix which complained that jackd is down even so I just restarted it with cadence. Therefore guitarix started qjackctl while cadence was still running and qjackctl restarted (or started) jackd.
Then there was sound from my speakers when I picked the strings of my guitar - not pretty but sound. Still know the sound of other applications vanished. After stopping jackd it also didn't return.

So something, somehow made something work but I don't understand anything that just happened. I would like to understand what is going to be able to make deterministic decisions in the future.
Also I would like to be able to still have sounds from other applications when running jackd and being able to restore my sound in a situation like this. (without rebooting the machine)

Sorry for this unprecise text-heavy style of posting my problem.

I will go to bed now (it is almost 2 am in Germany atm). Hear from you tomorrow and thank you very much in advance already for just reading about my little problems.
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LAM
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Re: Setting up USB-Audio-Interface + Guitarix to practice guitar

Post by LAM »

This post is full of infos on the Jack and PulseAudio subject: viewtopic.php?p=103154#p103154
Hopefully it will help you setting things and get started.

I also found a little tutorial Jack and Guitarx specific: https://www.howtoforge.com/tutorial/how ... -on-linux/

in mix, nobody can hear your screen

rakewezen
Posts: 2
Joined: Tue Jan 30, 2024 9:06 pm

Re: Setting up USB-Audio-Interface + Guitarix to practice guitar

Post by rakewezen »

this is basically my interest also, combining a usb audio interface with guitarix

had found that it is not difficult to get a guitar noise from the audio interface

there is a bash command - alsamixer, which will need to be installed from an alsa utility package

so, after the alsamixer command, hit f6 to select the usb audio interface, then switch the audio input from 'line' to 'instrument'

  • then and there the guitar is making a sound with the usb audio interface and an ubuntu booted computer.

the difficulty - the description of the guitar tone while hitting the strings is a way too normal tone like it is in bypass mode, no effects modeling, nothing

next part, guitarix uses jack and won't respond to the alsamixer trick

had tried to patch jack to alsa, and whether using qjackctl or ubuntu studio controls, so far, this accomplishes absolutely nothing...remains to be a guitar tone in bypass mode, and can adjust the volume

is there a method to get guitarix to patch from alsamixer to jack? or mostly no?

other than that - is there a such thing as amp modeling or audio interface software (linux compatible) that will link up ok with - the guitar is making a noise or sound - the alsamixer bash command. so, no jack connection and the audio interface is connected to the computer by usb. other software in question, since guitarix seems to not work with alsamixer bash command...

rakewezen
Posts: 2
Joined: Tue Jan 30, 2024 9:06 pm

Re: Setting up USB-Audio-Interface + Guitarix to practice guitar

Post by rakewezen »

kinda figured out the process, awhile after previous post.

so, including the alsamixer bash command in my previous post...

ended up going with cadence rather than qjackctl and to perform the patching a related package catia - either is found in the kxstudio repository

so with guitar attached to usb audio interface further connected to the linux booted computer - enter the bash command alsamixer, hit f6 and select usb audio interface and switch input from 'line' to 'instrument'

open the cadence package. under jack status hit configure, then look for the alsa tab and under interface select the usb audio interface in duplex mode. then under jack bridges, select bridge jack to alsa. hit start jack

open guitarix, if the jack connection is ok, in the lower-right corner there will be a couple connection status indicators in green, with an extra in grey

finally open catia to patch this stuff to guitarix. you should see boxes labeled system capture and sytem playback, and a box that shows gx head which is guitarix. draw a line from system capture to gx head (in) . then draw a line from gx head (out) to system playback

at this point the guitar tone is modified by guitarix and the sound or noise is questionably skrill beans and gravy...as in it flippin' works and stuff

had this audio interface and guitarix installed for an entire year, knowing the alsamixer bash command, without bridging jack to alsa and then patching the jack connection to guitarix

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