"JACK: Cannot callback the server in notification thread!"

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DisasterArea
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Posts: 28
Joined: Thu Mar 11, 2021 6:42 pm

"JACK: Cannot callback the server in notification thread!"

Post by DisasterArea »

Hello,
I'm using Ardour as a newbe and get stuck while adding a MIDI track with a-Fluid Synth as a instrument. I'm able to bind my MIDI Controller (Launchkey 25) to input. MIDI signals are shown when I hit a key but no sound comes out. If I add a MIDI track with a-reasonable synth as instrument, there is sound.
While searching for a reason for that behavior I saw the message "[ERROR]: JACK: Cannot callback the server in notification thread!" in the Ardour Log window.
  1. I am wondering, what this message means.
  2. How to get sound with other instrument than a-reasonable synth
Any idea?
Ubuntu Studio 22.04, Focusrite Scarlett 2i2, NI Komplete Audio 6, Acoustic and E-Guitar, E-Bass, Modular Synth (Cardinal) KORG Nano Control Studio, Novation Launchkey 25
tseaver
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Re: "JACK: Cannot callback the server in notification thread!"

Post by tseaver »

Do you have a GM soundfont installed / configured for the a-fluidSynth plugin to use? E.g.,

Code: Select all

$ sudo apt-get install fluid-soundfont-gm
on Ubuntu.
Ubuntu, Mixbus32C; acoustic blues / country / jazz
DisasterArea
Established Member
Posts: 28
Joined: Thu Mar 11, 2021 6:42 pm

Re: "JACK: Cannot callback the server in notification thread!"

Post by DisasterArea »

Dear @tseaver, I was able to get fluidsynth working. My misunderstanding was triggered by the fact, that reasonabel synth works out of the box but fluidsynth needs to be configured with a soundfont. To do this, one has to open the mixer view and edit the a-Fluidsynth Plugin. As I said, I am a newbe.

But what about the error message in the log? What is this about.

Regards
Ubuntu Studio 22.04, Focusrite Scarlett 2i2, NI Komplete Audio 6, Acoustic and E-Guitar, E-Bass, Modular Synth (Cardinal) KORG Nano Control Studio, Novation Launchkey 25
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