~❯ amixer                                                                                                       
Simple mixer control 'Master',0
  Capabilities: pvolume pswitch pswitch-joined
  Playback channels: Front Left - Front Right - Rear Left - Rear Right
  Limits: Playback 0 - 65536
  Mono:
  Front Left: Playback 7864 [12%] [on]
  Front Right: Playback 7864 [12%] [on]
  Rear Left: Playback 7864 [12%] [on]
  Rear Right: Playback 7864 [12%] [on]
Simple mixer control 'Capture',0
  Capabilities: cvolume cswitch cswitch-joined
  Capture channels: Front Left - Front Right
  Limits: Capture 0 - 65536
  Front Left: Capture 65536 [100%] [on]
  Front Right: Capture 65536 [100%] [on]
~❯ amixer controls                                                                                                   
numid=4,iface=MIXER,name='Master Playback Switch'
numid=3,iface=MIXER,name='Master Playback Volume'
numid=2,iface=MIXER,name='Capture Switch'
numid=1,iface=MIXER,name='Capture Volume'
~❯ amixer contents                                                                                                   
numid=4,iface=MIXER,name='Master Playback Switch'
  ; type=BOOLEAN,access=rw------,values=1
  : values=on
numid=3,iface=MIXER,name='Master Playback Volume'
  ; type=INTEGER,access=rw------,values=4,min=0,max=65536,step=1
  : values=7864,7864,7864,7864
numid=2,iface=MIXER,name='Capture Switch'
  ; type=BOOLEAN,access=rw------,values=1
  : values=on
numid=1,iface=MIXER,name='Capture Volume'
  ; type=INTEGER,access=rw------,values=2,min=0,max=65536,step=1
  : values=65536,65536