salut
Le man sur internet ne doit pas correspondre à la version d'alsa
Après quelques recherches et tests le fichier par défaut est bien /var/lib/alsa/asound.state
Avec l'init par systemd il existe un service qui gère la sauvegarde et la restauration: alsa-restore.service
systemctl status alsa-restore.service
● alsa-restore.service - Save/Restore Sound Card State
Loaded: loaded (/lib/systemd/system/alsa-restore.service; static; vendor preset: enabled)
Active: active (exited) since Thu 2017-08-17 13:10:15 CEST; 2min 39s ago
Docs: man:alsactl(1)
Process: 551 ExecStart=/usr/sbin/alsactl -E HOME=/run/alsa restore (code=exited, status=0/SUCCESS)
Main PID: 551 (code=exited, status=0/SUCCESS)
Tasks: 0 (limit: 4915)
CGroup: /system.slice/alsa-restore.service
août 17 13:10:11 debian systemd[1]: Starting Save/Restore Sound Card State...
août 17 13:10:15 debian systemd[1]: Started Save/Restore Sound Card State.
Toutefois je n'ai pas compris par quelle parametres son generes les valeurs des volume et j'ai donc préféré arreter puis desactiver ce service
systemctl stop alsa-restore.service
cd /lib/systemd/system/basic.target.wants
sudo rm alsa-restore.service
puis j'ai generé un fichier
sudo alsactl store
modifié par gedit les valeurs des volume pour les mettre à 50
root@debian:/l# cd /var/lib/alsa
root@debian:/var/lib/alsa# ls -alrt
total 16
drwxr-xr-x 76 root root 4096 août 2 13:22 ..
-rw-r--r-- 1 root root 4467 août 17 13:21 asound.state
drwxr-xr-x 2 root root 4096 août 17 13:21 .
root@debian:/var/lib/alsa# cat asound.state
state.SB {
control.1 {
iface MIXER
name 'Headphone Playback Volume'
value.0 0
value.1 0
comment {
access 'read write'
type INTEGER
count 2
range '0 - 127'
dbmin -9999999
dbmax 0
dbvalue.0 -9999999
dbvalue.1 -9999999
}
}
control.2 {
iface MIXER
name 'Headphone Playback Switch'
value.0 false
value.1 false
comment {
access 'read write'
type BOOLEAN
count 2
}
}
control.3 {
iface MIXER
name 'Speaker Playback Volume'
value.0 50
value.1 50
comment {
access 'read write'
type INTEGER
count 2
range '0 - 127'
dbmin -9999999
dbmax 0
dbvalue.0 0
dbvalue.1 0
}
}
control.4 {
iface MIXER
name 'Speaker Playback Switch'
value.0 true
value.1 true
comment {
access 'read write'
type BOOLEAN
count 2
}
}
control.5 {
iface MIXER
name 'Loopback Mixing'
value Disabled
comment {
access 'read write'
type ENUMERATED
count 1
item.0 Disabled
item.1 Enabled
}
}
control.6 {
iface MIXER
name 'Mic Playback Volume'
value.0 0
value.1 0
comment {
access 'read write'
type INTEGER
count 2
range '0 - 31'
dbmin -3450
dbmax 1200
dbvalue.0 -3450
dbvalue.1 -3450
}
}
control.7 {
iface MIXER
name 'Mic Playback Switch'
value.0 false
value.1 false
comment {
access 'read write'
type BOOLEAN
count 2
}
}
control.8 {
iface MIXER
name 'Auto-Mute Mode'
value Disabled
comment {
access 'read write'
type ENUMERATED
count 1
item.0 Disabled
item.1 Enabled
}
}
control.9 {
iface MIXER
name 'Capture Volume'
value.0 0
value.1 0
comment {
access 'read write'
type INTEGER
count 2
range '0 - 15'
dbmin 0
dbmax 2250
dbvalue.0 0
dbvalue.1 0
}
}
control.10 {
iface MIXER
name 'Capture Switch'
value.0 false
value.1 false
comment {
access 'read write'
type BOOLEAN
count 2
}
}
control.11 {
iface MIXER
name 'Internal Mic Boost Volume'
value.0 0
value.1 0
comment {
access 'read write'
type INTEGER
count 2
range '0 - 3'
dbmin 0
dbmax 3000
dbvalue.0 0
dbvalue.1 0
}
}
control.12 {
iface MIXER
name 'Mic Boost Volume'
value.0 0
value.1 0
comment {
access 'read write'
type INTEGER
count 2
range '0 - 3'
dbmin 0
dbmax 3000
dbvalue.0 0
dbvalue.1 0
}
}
control.13 {
iface MIXER
name 'Beep Playback Switch'
value false
comment {
access 'read write'
type BOOLEAN
count 1
}
}
control.14 {
iface MIXER
name 'Beep Playback Volume'
value 0
comment {
access 'read write'
type INTEGER
count 1
range '0 - 3'
dbmin -1800
dbmax 0
dbvalue.0 -1800
}
}
control.15 {
iface MIXER
name 'Master Playback Volume'
value 50
comment {
access 'read write'
type INTEGER
count 1
range '0 - 127'
dbmin -9999999
dbmax 0
dbvalue.0 -2700
}
}
control.16 {
iface MIXER
name 'Master Playback Switch'
value true
comment {
access 'read write'
type BOOLEAN
count 1
}
}
control.17 {
iface CARD
name 'Internal Mic Phantom Jack'
value true
comment {
access read
type BOOLEAN
count 1
}
}
control.18 {
iface CARD
name 'Mic Jack'
value false
comment {
access read
type BOOLEAN
count 1
}
}
control.19 {
iface CARD
name 'Front Headphone Jack'
value false
comment {
access read
type BOOLEAN
count 1
}
}
control.20 {
iface CARD
name 'Speaker Phantom Jack'
value true
comment {
access read
type BOOLEAN
count 1
}
}
control.21 {
iface PCM
name 'Playback Channel Map'
value.0 0
value.1 0
comment {
access read
type INTEGER
count 2
range '0 - 36'
}
}
control.22 {
iface PCM
name 'Capture Channel Map'
value.0 0
value.1 0
comment {
access read
type INTEGER
count 2
range '0 - 36'
}
}
control.23 {
iface MIXER
name 'PCM Playback Volume'
value.0 50
value.1 50
comment {
access 'read write user'
type INTEGER
count 2
range '0 - 255'
tlv '0000000100000008ffffec1400000014'
dbmin -5100
dbmax 0
dbvalue.0 -40
dbvalue.1 -40
}
}
control.24 {
iface MIXER
name 'Digital Capture Volume'
value.0 50
value.1 50
comment {
access 'read write user'
type INTEGER
count 2
range '0 - 120'
tlv '0000000100000008fffff44800000032'
dbmin -3000
dbmax 3000
dbvalue.0 2850
dbvalue.1 2850
}
}
}
root@debian:/var/lib/alsa#
je n'ai pas eu de probleme de son au redémarrage
on peur donc utiliser desux fenetre une pour alsamixer pour régler les niveaux et une pour faire le store quand on est content

Et donc on voit que 50 pour le niveau de volume correspond à 103 dans le fichier