~ $ amixer -c0 contents
numid=13,iface=CARD,name='HDMI/DP,pcm=3 Jack'
  ; type=BOOLEAN,access=r-------,values=1
  : values=off
numid=9,iface=CARD,name='Headphone Jack'
  ; type=BOOLEAN,access=r-------,values=1
  : values=off
numid=8,iface=CARD,name='Mic Phantom Jack'
  ; type=BOOLEAN,access=r-------,values=1
  : values=on
numid=10,iface=CARD,name='Speaker Phantom Jack'
  ; type=BOOLEAN,access=r-------,values=1
  : values=on
numid=7,iface=MIXER,name='Master Playback Switch'
  ; type=BOOLEAN,access=rw------,values=1
  : values=on
numid=6,iface=MIXER,name='Master Playback Volume'
  ; type=INTEGER,access=rw---R--,values=1,min=0,max=87,step=0
  : values=87
  | dBscale-min=-65.25dB,step=0.75dB,mute=0
numid=2,iface=MIXER,name='Headphone Playback Switch'
  ; type=BOOLEAN,access=rw------,values=2
  : values=off,off
numid=1,iface=MIXER,name='Headphone Playback Volume'
  ; type=INTEGER,access=rw---R--,values=2,min=0,max=87,step=0
  : values=0,0
  | dBscale-min=-65.25dB,step=0.75dB,mute=0
numid=20,iface=MIXER,name='PCM Playback Volume'
  ; type=INTEGER,access=rw---RW-,values=2,min=0,max=255,step=0
  : values=255,255
  | dBscale-min=-51.00dB,step=0.20dB,mute=0
numid=14,iface=MIXER,name='IEC958 Playback Con Mask'
  ; type=IEC958,access=r-------,values=1
  : values=[AES0=0x0f AES1=0xff AES2=0x00 AES3=0x00]
numid=15,iface=MIXER,name='IEC958 Playback Pro Mask'
  ; type=IEC958,access=r-------,values=1
  : values=[AES0=0x0f AES1=0x00 AES2=0x00 AES3=0x00]
numid=16,iface=MIXER,name='IEC958 Playback Default'
  ; type=IEC958,access=rw------,values=1
  : values=[AES0=0x04 AES1=0x00 AES2=0x00 AES3=0x00]
numid=17,iface=MIXER,name='IEC958 Playback Switch'
  ; type=BOOLEAN,access=rw------,values=1
  : values=off
numid=5,iface=MIXER,name='Auto-Mute Mode'
  ; type=ENUMERATED,access=rw------,values=1,items=2
  ; Item #0 'Disabled'
  ; Item #1 'Enabled'
  : values=1
numid=4,iface=MIXER,name='Speaker Playback Switch'
  ; type=BOOLEAN,access=rw------,values=2
  : values=on,on
numid=3,iface=MIXER,name='Speaker Playback Volume'
  ; type=INTEGER,access=rw---R--,values=2,min=0,max=87,step=0
  : values=87,87
  | dBscale-min=-65.25dB,step=0.75dB,mute=0
numid=12,iface=PCM,name='Capture Channel Map'
  ; type=INTEGER,access=r----R--,values=2,min=0,max=36,step=0
  : values=0,0
  | container
    | chmap-fixed=FL,FR

numid=11,iface=PCM,name='Playback Channel Map'
  ; type=INTEGER,access=r----R--,values=2,min=0,max=36,step=0
  : values=0,0
  | container
    | chmap-fixed=FL,FR

numid=18,iface=PCM,name='ELD',device=3
  ; type=BYTES,access=r--v----,values=0
  : values=
numid=19,iface=PCM,name='Playback Channel Map',device=3
  ; type=INTEGER,access=rw---R--,values=8,min=0,max=36,step=0
  : values=0,0,0,0,0,0,0,0
  | container
    | chmap-variable=FL,FR
    | chmap-variable=FL,FR,LFE
    | chmap-variable=FL,FR,FC
    | chmap-variable=FL,FR,RC
    | chmap-variable=FL,FR,RL,RR
    | chmap-variable=FL,FR,LFE,FC
    | chmap-variable=FL,FR,LFE,RC
    | chmap-variable=FL,FR,FC,RC
    | chmap-variable=FL,FR,FLC,FRC
    | chmap-variable=FL,FR,LFE,RL,RR
    | chmap-variable=FL,FR,FC,RL,RR
    | chmap-variable=FL,FR,LFE,FC,RC
    | chmap-variable=FL,FR,RL,RR,RC
    | chmap-variable=FL,FR,LFE,FLC,FRC
    | chmap-variable=FL,FR,FC,FLC,FRC
    | chmap-variable=FL,FR,RC,FLC,FRC
    | chmap-variable=FL,FR,LFE,FC,RL,RR
    | chmap-variable=FL,FR,LFE,RL,RR,RC
    | chmap-variable=FL,FR,FC,RL,RR,RC
    | chmap-variable=FL,FR,RL,RR,RLC,RRC
    | chmap-variable=FL,FR,LFE,FC,FLC,FRC
    | chmap-variable=FL,FR,LFE,RC,FLC,FRC
    | chmap-variable=FL,FR,FC,RC,FLC,FRC
    | chmap-variable=FL,FR,RL,RR,FLC,FRC
    | chmap-variable=FL,FR,FC,RL,RR,TFC
    | chmap-variable=FL,FR,FC,RL,RR,TC
    | chmap-variable=FL,FR,RL,RR,TFL,TFR
    | chmap-variable=FL,FR,RL,RR,FLW,FRW
    | chmap-variable=FL,FR,LFE,FC,RL,RR,RC
    | chmap-variable=FL,FR,LFE,RL,RR,RLC,RRC
    | chmap-variable=FL,FR,FC,RL,RR,RLC,RRC
    | chmap-variable=FL,FR,LFE,FC,RC,FLC,FRC
    | chmap-variable=FL,FR,LFE,RL,RR,FLC,FRC
    | chmap-variable=FL,FR,FC,RL,RR,FLC,FRC
    | chmap-variable=FL,FR,LFE,FC,RL,RR,TFC
    | chmap-variable=FL,FR,LFE,FC,RL,RR,TC
    | chmap-variable=FL,FR,LFE,RL,RR,TFL,TFR
    | chmap-variable=FL,FR,LFE,RL,RR,FLW,FRW
    | chmap-variable=FL,FR,FC,RL,RR,RC,TC
    | chmap-variable=FL,FR,FC,RL,RR,RC,TFC
    | chmap-variable=FL,FR,FC,RL,RR,TFC,TC
    | chmap-variable=FL,FR,FC,RL,RR,TFL,TFR
    | chmap-variable=FL,FR,FC,RL,RR,FLW,FRW
    | chmap-variable=FL,FR,LFE,FC,RL,RR,RLC,RRC
    | chmap-variable=FL,FR,LFE,FC,RL,RR,FLC,FRC
    | chmap-variable=FL,FR,LFE,FC,RL,RR,RC,TC
    | chmap-variable=FL,FR,LFE,FC,RL,RR,RC,TFC
    | chmap-variable=FL,FR,LFE,FC,RL,RR,TFC,TC
    | chmap-variable=FL,FR,LFE,FC,RL,RR,TFL,TFR
    | chmap-variable=FL,FR,LFE,FC,RL,RR,FLW,FRW