Thank you Michael Heuer, for your reply. I have already installed jackd and QJackCtl, but I am not so happy with it. It is much easer to work with ChucK compiled to use alsa and just start one single program (* chuck) than to wary about starting jackd, controlling it... Very likely I am missing something about jack but I have never made it to work smoothly. There were always some troubles with applications that utilize sound card when I run jack server, so I gave up. On the other hand, I don't understand why ChucK can not use sound card as any other application on my computer. For example: command line mp3 player mpg321 can play a mp3-file simultaneously with other programs. I can start several mpg321 commands from terminal and there will be no complains about hardware device being used. The same is with other audio/video players on my computer. None of them requires exclusively access to sound card hardware, and they all can cooperate smoothly. I would like very much if ChucK could do so. Vitalije