Thanks a lot for your reply, Patrick! I will keep experimenting with different combinations of format settings. About this: Do you have a "layer" between the drivers (alsa oss etc...) I am not sure of what you mean (I am not an expert :) ). Of course the computer has alsa, but as far as I understand all the software involved (virtual keiboard, QSynth, JACK) are connected directly, without intermediaries. Can you give me some tests to do, to determine whether there is a layer in between or not? Again, thanks a lot! Fabio On 2022-11-28 13:16, Patrick Pouget wrote: White noise is, in general, due to format mismatch. I mean data types, sample rate, number of channels etc... I can see 2 causes * Jack should be queried for the format by the application. If you have the problem with many, it is not the case * jack relay on drivers that return wrong informations or no information or a default information. Do you have a "layer" between the drivers (alsa oss etc...) and jack? On Mon, 2022-11-28 at 09:14 +0100, Patrick Pouget wrote: White noise is, in general, due to format mismatch. I mean data types, sample rate, number of channels etc... I can see 2 causes * Jack should be queried for the format by the application. If you have the problem with many, it is not the case * jack relay on drivers that return wrong informations or no information or a default information. Do you have a "layer" between the drivers (alsa oss etc...) and jack? On Mon, 2022-11-28 at 09:03 +0500, Fabio G wrote: Hello to all! <https://sound.stackexchange.com/posts/51899/timeline> I am experimenting with audio production under Linux Mint 20.3 (based on Ubuntu 20.04). I managed to install a low latency kernel, then I have installed JACK, and Qsynth, following the steps described in this tutorial: <http://www.tedfelix.com/linux/linux-midi.html> http://www.tedfelix.com/linux/linux-midi.html Everything seems to work fine if I use Qsynth and pulseaudio: I use the vmpk simple virtual keyboard, and I have good output sound. I have also tested JACK, as suggested in the tutorial using $ jack-play test.wav and I hear the right clean output. However, when I tell Qsynth to use JACK, I have a lot of noise. When I hit a key I have "white noise" for few milliseconds instead of the key sound, and only when it fades I have a little bit of the note that I was supposed to play. I have the same "white noise" problem is I use Rose Garden. I have tried to change the sample rate and the frames/period settings, and also the Timeout, in JACK, but the problem stays the same. Thank you in advance for any help you can give. Best, Fabio _______________________________________________ JackAudio mailing list JackAudio(a)lists.linuxaudio.org https://lists.linuxaudio.org/listinfo/jackaudio _______________________________________________ JackAudio mailing list JackAudio(a)lists.linuxaudio.org https://lists.linuxaudio.org/listinfo/jackaudio