Re: [Jack-Devel] USB MIDI keyboard Akai LPK, jackd

On 11/03/2014 08:36 AM, Łukasz Kidziński wrote:
> I got Akai LPK25 and I am trying to make it working on my Ubuntu. I tried
> to follow a tutorial
> http://terokarvinen.com/2014/usb-midi-keyboard-on-linux-akai-lpk25-professional.
> I have no knowledge about jack and other applications involed so let me
> write everything since I don't know where to look for the problem. I posted
> the problem here
> http://askubuntu.com/questions/544672/usb-midi-keyboard-akai-lpk-jackd and
> they suggested to aks you here.
> 
> When I run
> 
>     zynjacku &
> 

Hello Łukasz,

zynjacky is hopelessly outdated and you don't need it to set up your
LPK25. Also you don't aconnectgui.

This is what I would do to get things going:
- Connect your LPK25
- Install necessary software: apt-get install jackd qjackctl zynaddsubfx
- Start QjackCtl and set it up for your soundcard, some googling should
get you started
- Start ZynAddSubFX and make the connections in the Audio tab from the
Zyn output ports to your playback ports.
- Do the same for MIDI, connect your LPK25 output to the Zyn input in
the ALSA tab of the QjackCTL Connections window.

That should do the trick, if not, shoot!

> I get errors
> 
>     Cannot connect to server socket err = No such file or directory
>     Cannot connect to server request channel
>     jack server is not running or cannot be started
>     Failed to connect to JACK.
>     Failed to initialize zynjacku engine
> 
> I figured I may need to run the jackd server first so I installed it and ran
> 
>     jackd -sRp 70 -d alsa -d hw:1 -r 44100 -H -z s
> 

jackd -s is not necessary in most cases. -R (real-time mode) is a
default option so not necessary. -p 70 sets JACK to use 70 ports, you
probably mean -P 70, to set JACK's priority to 70. Afaik -H is only used
if your soundcard supports hardware monitoring. What soundcard are you
using? You also don't need to set dithering (-z s), the default setting
should be just fine.

> but I still can't make zynjacku running and get
> 
>     flex scanner jammed
> 
> If I run zynaddsubfx and aconnectgui I manage to get signal from the
> keyboard (the indicator at the bottom gets blue) but I can't hear anythnig.
> 
> I tried to manually send some signal to jackd by `ecasound` and it reaches
> the jackd server but again I can't hear any sound.
> 
> I have totally no experience with jackd so that's why my trials are that
> random. Thanks in advance for your help.
> 
> If I run `jackd -sRp 70 -d alsa -d hw:1 -r 44100 -H -z s`, I get
> 
>     no message buffer overruns
>     JACK server starting in realtime mode with priority 10
>     audio_reservation_init
>     Acquire audio card Audio0
>     creating alsa driver ...
> hw:0|hw:0|1024|2|44100|0|0|hwmon|swmeter|-|32bit
>     Failed to open server
> 

Try raising the verbosity of JACK by adding -v:

jackd -v -P 70 -d alsa -d hw:1 -r 44100

> Thank you very much in advance,
> 
> Best,
> Łukasz Kidziński

Best,

Jeremy

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