GuitarX virtual amp using RockSmith Real Tone Cable

[Dread Knight]

Hello! I have an electric guitar and a Rocksmith Real Tone cable. I'm running KDE Neon and did most things this guy here did viewtopic.php?f=64&t=21325 except installing a low latency kernel. I have a pretty good workstation, but no audio interface (yet?), was wondering if I could hear my guitar in real time from my computer speakers (as I don't have amp/combo/pedals) using GuitarX, maybe even w/ some effects.

Seems GuitarX recognizes the guitar (used qJackctl and Cadence) and could even record it using Audacity, but no sound from my speakers. Ideas?

[milo]

I have one of those in a desk drawer that I have never used, but I played around with it for a while when my cousin gave it to me. It is essentially a 1-way USB audio interface, with only the input from whatever you plug in at the other end of the cable. It has not audio output, so you have have to specify something else as the output device. You can do that with JACK with the qjackctl setting, on the advanced tab. It should work with your Rocksmith as the input and your computer's sound card as the output.

[tavasti]

Yeah, Rocksmith cable is audio interface. So you need to start jack using your built-in audio device.

Run 'arecord -l' to get list of audio devices:

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tavasti@hermo:~$ arecord -l
**** List of CAPTURE Hardware Devices ****
card 4: Adapter [Rocksmith USB Guitar Adapter], device 0: USB Audio [USB Audio]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

From there I can see that name 'Adapter' shoud work:

Code: Select all

alsa_in -d hw:Adapter -j rocksmith 

Now you should have port called rocksmith you can connect to your Guitarix in qjackctl / some other program you use to connect jack audio.

[Dread Knight]

Yeah, I'm aware it has an audio interface in it, just edited the title badly when I was tired and frustrated. Edited it again.

@milo Thanks for the reply. It's what I was doing, guess I need to get more technical in order to hopefully pinpoint the issue, by listing stuff and posting screenies.

@tavasti It's listed

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dread@FreezingMoon:~$ arecord -l
**** List of CAPTURE Hardware Devices ****
card 2: Generic [HD-Audio Generic], device 0: ALC892 Analog [ALC892 Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 2: Generic [HD-Audio Generic], device 2: ALC892 Alt Analog [ALC892 Alt Analog]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
card 3: Adapter [Rocksmith USB Guitar Adapter], device 0: USB Audio [USB Audio]
  Subdevices: 1/1
  Subdevice #0: subdevice #0
dread@FreezingMoon:~$ 

Ran the other command as well, with JACK on it runs into error; here's the output with it off:

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dread@FreezingMoon:~$ alsa_in -d hw:Adapter -j rocksmith
Cannot connect to server socket err = Connection refused
Cannot connect to server request channel
jackdmp 1.9.12
Copyright 2001-2005 Paul Davis and others.
Copyright 2004-2016 Grame.
Copyright 2016-2017 Filipe Coelho.
jackdmp comes with ABSOLUTELY NO WARRANTY
This is free software, and you are welcome to redistribute it
under certain conditions; see the file COPYING for details
no message buffer overruns
no message buffer overruns
no message buffer overruns
JACK server starting in realtime mode with priority 10
self-connect-mode is "Don't restrict self connect requests"
audio_reservation_init
Acquire audio card Audio3
Acquire audio card Audio2
creating alsa driver ... hw:Generic|hw:Adapter|512|2|44100|0|0|nomon|swmeter|-|32bit
configuring for 44100Hz, period = 512 frames (11.6 ms), buffer = 2 periods
ALSA: final selected sample format for capture: 16bit little-endian
ALSA: use 2 periods for capture
ALSA: final selected sample format for playback: 32bit integer little-endian
ALSA: use 2 periods for playback
Capture open error: Device or resource busy
dread@FreezingMoon:~$ Unknown error...
terminate called after throwing an instance of 'Jack::JackTemporaryException'
  what():  

Here's what I have as input/out in JACK

jack.jpg (83.59 KiB) Viewed 4796 times

I'm a bit confused as why hw:Speaker listed as an output devices but throws X-Runs when selected. Guess that's just to show me that I have usb speakers connected but I should only send stuff to a sound card, not directly to them.

And here's what the connections are by default (I tried a lot of ways, I do tend to connect amp head to system to see stuff moving in GuitarX)

jack 2.jpg (42.68 KiB) Viewed 4796 times

Would I need to manually configure GuitarX/Jack Ports as well to eventually get sound off my speakers?
And I'm somewhat confused if the output should be system or PulseAudio JACK Sink...

[milo]

It looks like you need to connect Guitarix to your system output. The guitar signal comes in at gx_head_amp, and then goes to gx_head_fx, so connect gx_head_fx to system and see if that gives you sound.

EDIT: Also, have you verified that your JACK sound output is working with some other app, like Audacious, VLC or whatnot?

[tavasti]

Ran the other command as well, with JACK on it runs into error; here's the output with it off:

Code: Select all

dread@FreezingMoon:~$ alsa_in -d hw:Adapter -j rocksmith
Cannot connect to server socket err = Connection refused
Cannot connect to server request channel
jackdmp 1.9.12
Copyright 2001-2005 Paul Davis and others.
Copyright 2004-2016 Grame.
Copyright 2016-2017 Filipe Coelho.
jackdmp comes with ABSOLUTELY NO WARRANTY
This is free software, and you are welcome to redistribute it
under certain conditions; see the file COPYING for details
no message buffer overruns
no message buffer overruns
no message buffer overruns
JACK server starting in realtime mode with priority 10

For me it looks like you did not have jack running when running alsa_in, but jack was started with it? Jack should be running when running alsa_in.
Or am I mistaken?

[Dread Knight]

I've played around some more with this stuff and finally managed to get everything working, thanks for bearing with me, guys.

Maybe this bit will help others: seems that my problem was the actual sample rate as I was getting errors with 44.1k for hw:Speaker output.
Bumping that to 48k eliminated the X-Runs, so it's all good now. Already had quite some fun with GuitarX and Rakarrack (even if it looks hideous).

The only thing I haven't managed was getting the output through my Bluedio bluetooth headset, but I'm guessing that's not doable, so will see about a new jack cable for it soon, as old one broke easily, oh well...

[milo]

Glad to hear it! Congratulations on your new Linux audio setup! When you get something recorded, please post it to the Original Recordings subforum so we can have a listen.

Yeah, I think you are right about Bluetooth headphones being a problem for JACK currently. But I am not an expert there.

[Dread Knight]

Thanks! I'm rather new to playing and making music, it will take a rather long time to have something decent going on, but making constant progress, so hopefully will get there. I'm happy that I've managed to go digital with this by avoiding combos, effect pedals and all that old-school stuff for now, as my budget is pretty low and I don't have much space atm.

[Baggypants]

The "easiest" way to run bluetooth audio with jack is to run pulseaudio with the jack sink.

[Dread Knight]

The "easiest" way to run bluetooth audio with jack is to run pulseaudio with the jack sink.

Hmm, I have that installed and such, but when I pair my bt headset, it has it's own entry in the audio applet as an output, so even if I have selected as audio device, I can still hear stuff through my speakers instead; also tried "Play all audio via this device" option available in KDE...

[Baggypants]

make sure you have pavucontrol installed and that the bluetooth device is selected as the output device and that in jack all the sound is heading to the pulseaudio sink. It will also be quite delayed.