有两个输出设备：在我的电脑headphone中 line out。我可以选择其中一个作为输出设备PulseAudio Volume Control。amixer可以做同样的工作pulseaudio吗？
我想选择speaker播放card 1音频。
amixer -c 1 set "speaker" On
amixer: Unable to find simple control 'speaker',0
amixer -c 1 set "speaker" 10db
amixer: Unable to find simple control 'speaker',0
他们两个都不能工作。
@MC68020，无效命令：
debian@debian:~$ amixer -c 1 scontrols
Simple mixer control 'Master',0
Simple mixer control 'Headphone',0
Simple mixer control 'Headphone+LO',0
Simple mixer control 'PCM',0
Simple mixer control 'Front',0
Simple mixer control 'Front Mic',0
Simple mixer control 'Front Mic Boost',0
Simple mixer control 'Surround',0
Simple mixer control 'Center',0
Simple mixer control 'LFE',0
Simple mixer control 'Line',0
Simple mixer control 'Line Boost',0
Simple mixer control 'IEC958',0
Simple mixer control 'IEC958 Default PCM',0
Simple mixer control 'Capture',0
Simple mixer control 'Capture',1
Simple mixer control 'Auto-Mute Mode',0
Simple mixer control 'Channel Mode',0
Simple mixer control 'Input Source',0
Simple mixer control 'Input Source',1
Simple mixer control 'Loopback Mixing',0
Simple mixer control 'Rear Mic',0
Simple mixer control 'Rear Mic Boost',0
debian@debian:~$ amixer -c 1 sset Headphone 80%
amixer: Invalid command!
debian@debian:~$ amixer -c 1 set Headphone 80%
amixer: Invalid command!
debian@debian:~$ amixer -c 1 set "Headphone" 80%
amixer: Invalid command!
debian@debian:~$ amixer -c 1 sset "Headphone" 80%
amixer: Invalid command!
关于我的混合器的更多信息：
debian@debian:~$ amixer -v
amixer version 1.2.4
debian@debian:~$ amixer -c 1 sget Headphone
Simple mixer control 'Headphone',0
Capabilities: pswitch
Playback channels: Front Left - Front Right
Mono:
Front Left: Playback [on]
Front Right: Playback [on]