Simple mixer control 'Front',0
  Capabilities: pvolume pswitch
  Playback channels: Front Left - Front Right
  Limits: Playback 0 - 64
  Mono:
  Front Left: Playback 43 [67%] [-21.00dB] [on]
  Front Right: Playback 43 [67%] [-21.00dB] [on]
Simple mixer control 'Mic',0
  Capabilities: pvolume pswitch
  Playback channels: Front Left - Front Right
  Limits: Playback 0 - 31
  Mono:
  Front Left: Playback 0 [0%] [-34.50dB] [on]
  Front Right: Playback 0 [0%] [-34.50dB] [on]
Simple mixer control 'Capture',0
  Capabilities: cvolume cswitch
  Capture channels: Front Left - Front Right
  Limits: Capture 0 - 31
  Front Left: Capture 0 [0%] [-13.50dB] [on]
  Front Right: Capture 0 [0%] [-13.50dB] [on]
Simple mixer control 'Input Source',0
  Capabilities: enum
  Items: 'Mic'
  Item0: 'Mic'
[root@cangrejo Desktop]# amixer -c7 contents
numid=2,iface=MIXER,name='Front Playback Switch'
  ; type=BOOLEAN,access=rw------,values=2
  : values=on,on
numid=1,iface=MIXER,name='Front Playback Volume'
  ; type=INTEGER,access=rw---R--,values=2,min=0,max=64,step=0
  : values=43,43
  | dBscale-min=-64.00dB,step=1.00dB,mute=0
numid=4,iface=MIXER,name='Mic Playback Switch'
  ; type=BOOLEAN,access=rw------,values=2
  : values=on,on
numid=3,iface=MIXER,name='Mic Playback Volume'
  ; type=INTEGER,access=rw---R--,values=2,min=0,max=31,step=0
  : values=0,0
  | dBscale-min=-34.50dB,step=1.50dB,mute=0
numid=6,iface=MIXER,name='Capture Switch'
  ; type=BOOLEAN,access=rw------,values=2
  : values=on,on
numid=5,iface=MIXER,name='Capture Volume'
  ; type=INTEGER,access=rw---R--,values=2,min=0,max=31,step=0
  : values=0,0
  | dBscale-min=-13.50dB,step=1.50dB,mute=0
numid=7,iface=MIXER,name='Input Source'
  ; type=ENUMERATED,access=rw------,values=1,items=1
  ; Item #0 'Mic'
  : values=0