Hi, I don’t really understand the problematics of your issue, but in my config I just delete pulseaudio from %desktop-services and add pipewire in my home-services.
pw-jack and pulseaudio apps work fine for me this way. config.scm: (modify-services %desktop-services (delete pulseaudio-service-type) (delete alsa-service-type)) home-configuration.scm: (service home-pipewire-service-type) Specifically, I don’t understand why you try to start jackd through pw-jack, you just need to start your app directly like the example in the manual: pw-jack mpv -ao=jack sound-file.wav In hope that helps, Noé