d%  amixer set 'PCM',1 on
Simple mixer control 'PCM',1
  Capabilities: volume pswitch cswitch
  Playback channels: Front Left - Front Right
  Capture channels: Front Left - Front Right
  Limits: 0 - 31
  Front Left: 0 [0%] [-50.00dB] Playback [on] Capture [off]
  Front Right: 0 [0%] [-50.00dB] Playback [on] Capture [off]