gentoo中配置alsa显现问题，帮忙！

nxufeng

打开声道时：
bash-2.05b# amixer set Master 100 unmute
amixer: Unknown playback setup 'unmute'..

bash-2.05b# amixer set PCM 100 unmute
amixer: Unable to find simple control 'PCM',0

bash-2.05b# amixer set Center 100 unmute
amixer: Unable to find simple control 'Center',0

bash-2.05b# amixer set Surround 100 unmute
amixer: Unable to find simple control 'Surround',0
请问怎样解决？谢过先了！
附alsamixer截图