5 - Les serveurs son : JACK, PulseAudio et autres...

Bonjour,

j'ai installé ce matin une carte M-AUDIO Delta 1010LT, à priori 100% compatible avec Linux, afin de remplacer une carte Terratec Aureon 5.1 PCI qui a un gros problème de souffle en entrée ligne.

Mon système est Xubuntu 14.04 LTS, avec une config modeste mais à priori largement suffisante pour cette vieille carte son (Pentium 4 631 3Ghz en socket LGA 775 , 2Go de Ram),et je ferai rarement du multipiste.
Elle fonctionne très bien sans Jack, la gestion de la carte avec mudita24 est très similaire à celle sous windows, de ce côté là aucun souci.

Par contre dès que j'essaye de lancer jack, j'obtiens ces messages d'erreur.

10:54:53.143 Baie de brassage désactivée.
10:54:53.148 Réinitialisation des statistiques.
10:54:53.211 Changement des connexions ALSA.
10:54:53.236 DBUS : le service est disponible (org.jackaudio.service soit jackdbus).
Cannot connect to server socket err = Aucun fichier ou dossier de ce type
Cannot connect to server request channel
jack server is not running or cannot be started
10:54:53.292 Changement du graphique des connexions ALSA.
(qjackctl:4005): Gtk-CRITICAL **: IA__gtk_widget_get_direction: assertion 'GTK_IS_WIDGET (widget)' failed
(qjackctl:4005): Gtk-CRITICAL **: IA__gtk_widget_get_direction: assertion 'GTK_IS_WIDGET (widget)' failed
(qjackctl:4005): Gtk-CRITICAL **: IA__gtk_widget_get_direction: assertion 'GTK_IS_WIDGET (widget)' failed
(qjackctl:4005): Gtk-CRITICAL **: IA__gtk_widget_get_direction: assertion 'GTK_IS_WIDGET (widget)' failed
(qjackctl:4005): Gtk-CRITICAL **: IA__gtk_widget_get_direction: assertion 'GTK_IS_WIDGET (widget)' failed
(qjackctl:4005): Gtk-CRITICAL **: IA__gtk_widget_get_direction: assertion 'GTK_IS_WIDGET (widget)' failed
(qjackctl:4005): Gtk-CRITICAL **: IA__gtk_widget_get_direction: assertion 'GTK_IS_WIDGET (widget)' failed
(qjackctl:4005): Gtk-CRITICAL **: IA__gtk_widget_get_direction: assertion 'GTK_IS_WIDGET (widget)' failed
(qjackctl:4005): Gtk-CRITICAL **: IA__gtk_widget_get_direction: assertion 'GTK_IS_WIDGET (widget)' failed
(qjackctl:4005): Gtk-CRITICAL **: IA__gtk_widget_get_direction: assertion 'GTK_IS_WIDGET (widget)' failed
10:55:54.346 DBUS : impossible de démarrer le serveur JACK. Désolé
Tue Nov 29 10:55:53 2016: Starting jack server...
Tue Nov 29 10:55:53 2016: Jack: Server `default' registered
Tue Nov 29 10:55:53 2016: Jack: JackConnectionManager::InitConnections size = 6522944 
Tue Nov 29 10:55:54 2016: Jack: JackConnectionManager::InitClients
Tue Nov 29 10:55:54 2016: JACK server starting in realtime mode with priority 80
Tue Nov 29 10:55:54 2016: Jack: JackShmMem::new index = 0 attached = b09ff000 size = 82274202 
Tue Nov 29 10:55:54 2016: Jack: JackShmMem::new placement size = 13047706
Tue Nov 29 10:55:54 2016: Jack: Succeeded in locking 82274202 byte memory area
Tue Nov 29 10:55:54 2016: Jack: JackConnectionManager::InitConnections size = 6522944 
Tue Nov 29 10:55:54 2016: Jack: JackConnectionManager::InitClients
Tue Nov 29 10:55:54 2016: Jack: JackConnectionManager::InitConnections size = 6522944 
Cannot connect to server socket err = Aucun fichier ou dossier de ce type
Cannot connect to server request channel
jack server is not running or cannot be started
(qjackctl:4005): Gtk-CRITICAL **: IA__gtk_widget_get_direction: assertion 'GTK_IS_WIDGET (widget)' failed
(qjackctl:4005): Gtk-CRITICAL **: IA__gtk_widget_get_direction: assertion 'GTK_IS_WIDGET (widget)' failed
Tue Nov 29 10:55:54 2016: Jack: JackConnectionManager::InitClients
Tue Nov 29 10:55:54 2016: Jack: JackShmMem::new index = 1 attached = b77c0000 size = 1186 
Tue Nov 29 10:55:54 2016: Jack: Succeeded in locking 1186 byte memory area
Tue Nov 29 10:55:54 2016: ERROR: cannot register object path "/org/freedesktop/ReserveDevice1/Audio2": A handler is already registered for /org/freedesktop/ReserveDevice1/Audio2
Tue Nov 29 10:55:54 2016: ERROR: Failed to acquire device name : Audio2 error : A handler is already registered for /org/freedesktop/ReserveDevice1/Audio2
Tue Nov 29 10:55:54 2016: ERROR: Audio device hw:M1010LT cannot be acquired...
Tue Nov 29 10:55:54 2016: ERROR: Cannot initialize driver
Tue Nov 29 10:55:54 2016: ERROR: JackServer::Open failed with -1
Tue Nov 29 10:55:54 2016: ERROR: Failed to open server
Tue Nov 29 10:55:55 2016: Saving settings to "/home/jean-philippe/.config/jack/conf.xml" ...
10:56:00.540 Impossible de connecter le serveur JACK comme client. - L'opération a échoué. - Incapable de se connecter au serveur. Veuillez consulter la fenêtre des messages pour plus d'informations.
Cannot connect to server socket err = Aucun fichier ou dossier de ce type
Cannot connect to server request channel
jack server is not running or cannot be started

Une idée du problème ?