好的，故事是这样的。我有一个 JDS Lab. C5D USB DAC 大约一年了，昨天我想试试 Ubuntu 14.04。所以，我安装了 Ubuntu，做了一些更新并连接了 DAC（sudo alsa reload并killall pulseaudio使用了命令）。
在我进入“声音设置“菜单并选择 C5D 的模拟输出，我尝试了测试声音。”左前方“ 和 ”右前“ 产生的声音 ”嗯嗯嗯“ 和 ”嗯嗯嗯“。我甚至尝试播放一些音乐和视频——结果是一样的。
也许是 DAC 问题？所以我加载了 Windows，然后加载了 Kali Linux，在两个系统中都运行良好。
返回 Ubuntu 后，我尝试查看系统是否正确识别 DAC，因此这是某些命令的输出：
$ lsusb
Bus 002 Device 004: ID 1532:010d Razer USA, Ltd
Bus 002 Device 008: ID 262a:1120 <-------------THIS IS C5D
Bus 002 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 006 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 005 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 004 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 003 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
Bus 001 Device 005: ID 0cf3:9271 Atheros Communications, Inc. AR9271 802.11n
Bus 001 Device 004: ID 0480:a207 Toshiba America Info. Systems, Inc.
Bus 001 Device 003: ID 1038:1369 Ideazon, Inc.
Bus 001 Device 002: ID 8087:0024 Intel Corp. Integrated Rate Matching Hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
$ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: DS [Xonar DS], device 0: Multichannel [Multichannel]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: DS [Xonar DS], device 1: Digital [Digital]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: PCH [HDA Intel PCH], device 0: ALC889 Analog [ALC889 Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: PCH [HDA Intel PCH], device 1: ALC889 Digital [ALC889 Digital]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: PCH [HDA Intel PCH], device 3: HDMI 0 [HDMI 0]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 2: NVidia [HDA NVidia], device 3: HDMI 0 [HDMI 0]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 2: NVidia [HDA NVidia], device 7: HDMI 0 [HDMI 0]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 2: NVidia [HDA NVidia], device 8: HDMI 0 [HDMI 0]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 2: NVidia [HDA NVidia], device 9: HDMI 0 [HDMI 0]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 3: DAC [C5D Amp DAC], device 0: USB Audio [USB Audio]
Subdevices: 1/1
Subdevice #0: subdevice #0
$ aplay -L
default
Playback/recording through the PulseAudio sound server
null
Discard all samples (playback) or generate zero samples (capture)
pulse
PulseAudio Sound Server
sysdefault:CARD=DS
Xonar DS, Multichannel
Default Audio Device
front:CARD=DS,DEV=0
Xonar DS, Multichannel
Front speakers
surround40:CARD=DS,DEV=0
Xonar DS, Multichannel
4.0 Surround output to Front and Rear speakers
surround41:CARD=DS,DEV=0
Xonar DS, Multichannel
4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=DS,DEV=0
Xonar DS, Multichannel
5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=DS,DEV=0
Xonar DS, Multichannel
5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=DS,DEV=0
Xonar DS, Multichannel
7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
iec958:CARD=DS,DEV=0
Xonar DS, Multichannel
IEC958 (S/PDIF) Digital Audio Output
dmix:CARD=DS,DEV=0
Xonar DS, Multichannel
Direct sample mixing device
dmix:CARD=DS,DEV=1
Xonar DS, Digital
Direct sample mixing device
dsnoop:CARD=DS,DEV=0
Xonar DS, Multichannel
Direct sample snooping device
dsnoop:CARD=DS,DEV=1
Xonar DS, Digital
Direct sample snooping device
hw:CARD=DS,DEV=0
Xonar DS, Multichannel
Direct hardware device without any conversions
hw:CARD=DS,DEV=1
Xonar DS, Digital
Direct hardware device without any conversions
plughw:CARD=DS,DEV=0
Xonar DS, Multichannel
Hardware device with all software conversions
plughw:CARD=DS,DEV=1
Xonar DS, Digital
Hardware device with all software conversions
sysdefault:CARD=PCH
HDA Intel PCH, ALC889 Analog
Default Audio Device
front:CARD=PCH,DEV=0
HDA Intel PCH, ALC889 Analog
Front speakers
surround40:CARD=PCH,DEV=0
HDA Intel PCH, ALC889 Analog
4.0 Surround output to Front and Rear speakers
surround41:CARD=PCH,DEV=0
HDA Intel PCH, ALC889 Analog
4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=PCH,DEV=0
HDA Intel PCH, ALC889 Analog
5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=PCH,DEV=0
HDA Intel PCH, ALC889 Analog
5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=PCH,DEV=0
HDA Intel PCH, ALC889 Analog
7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
iec958:CARD=PCH,DEV=0
HDA Intel PCH, ALC889 Digital
IEC958 (S/PDIF) Digital Audio Output
hdmi:CARD=PCH,DEV=0
HDA Intel PCH, HDMI 0
HDMI Audio Output
dmix:CARD=PCH,DEV=0
HDA Intel PCH, ALC889 Analog
Direct sample mixing device
dmix:CARD=PCH,DEV=1
HDA Intel PCH, ALC889 Digital
Direct sample mixing device
dmix:CARD=PCH,DEV=3
HDA Intel PCH, HDMI 0
Direct sample mixing device
dsnoop:CARD=PCH,DEV=0
HDA Intel PCH, ALC889 Analog
Direct sample snooping device
dsnoop:CARD=PCH,DEV=1
HDA Intel PCH, ALC889 Digital
Direct sample snooping device
dsnoop:CARD=PCH,DEV=3
HDA Intel PCH, HDMI 0
Direct sample snooping device
hw:CARD=PCH,DEV=0
HDA Intel PCH, ALC889 Analog
Direct hardware device without any conversions
hw:CARD=PCH,DEV=1
HDA Intel PCH, ALC889 Digital
Direct hardware device without any conversions
hw:CARD=PCH,DEV=3
HDA Intel PCH, HDMI 0
Direct hardware device without any conversions
plughw:CARD=PCH,DEV=0
HDA Intel PCH, ALC889 Analog
Hardware device with all software conversions
plughw:CARD=PCH,DEV=1
HDA Intel PCH, ALC889 Digital
Hardware device with all software conversions
plughw:CARD=PCH,DEV=3
HDA Intel PCH, HDMI 0
Hardware device with all software conversions
hdmi:CARD=NVidia,DEV=0
HDA NVidia, HDMI 0
HDMI Audio Output
hdmi:CARD=NVidia,DEV=1
HDA NVidia, HDMI 0
HDMI Audio Output
hdmi:CARD=NVidia,DEV=2
HDA NVidia, HDMI 0
HDMI Audio Output
hdmi:CARD=NVidia,DEV=3
HDA NVidia, HDMI 0
HDMI Audio Output
dmix:CARD=NVidia,DEV=3
HDA NVidia, HDMI 0
Direct sample mixing device
dmix:CARD=NVidia,DEV=7
HDA NVidia, HDMI 0
Direct sample mixing device
dmix:CARD=NVidia,DEV=8
HDA NVidia, HDMI 0
Direct sample mixing device
dmix:CARD=NVidia,DEV=9
HDA NVidia, HDMI 0
Direct sample mixing device
dsnoop:CARD=NVidia,DEV=3
HDA NVidia, HDMI 0
Direct sample snooping device
dsnoop:CARD=NVidia,DEV=7
HDA NVidia, HDMI 0
Direct sample snooping device
dsnoop:CARD=NVidia,DEV=8
HDA NVidia, HDMI 0
Direct sample snooping device
dsnoop:CARD=NVidia,DEV=9
HDA NVidia, HDMI 0
Direct sample snooping device
hw:CARD=NVidia,DEV=3
HDA NVidia, HDMI 0
Direct hardware device without any conversions
hw:CARD=NVidia,DEV=7
HDA NVidia, HDMI 0
Direct hardware device without any conversions
hw:CARD=NVidia,DEV=8
HDA NVidia, HDMI 0
Direct hardware device without any conversions
hw:CARD=NVidia,DEV=9
HDA NVidia, HDMI 0
Direct hardware device without any conversions
plughw:CARD=NVidia,DEV=3
HDA NVidia, HDMI 0
Hardware device with all software conversions
plughw:CARD=NVidia,DEV=7
HDA NVidia, HDMI 0
Hardware device with all software conversions
plughw:CARD=NVidia,DEV=8
HDA NVidia, HDMI 0
Hardware device with all software conversions
plughw:CARD=NVidia,DEV=9
HDA NVidia, HDMI 0
Hardware device with all software conversions
sysdefault:CARD=DAC
C5D Amp DAC, USB Audio
Default Audio Device
front:CARD=DAC,DEV=0
C5D Amp DAC, USB Audio
Front speakers
surround40:CARD=DAC,DEV=0
C5D Amp DAC, USB Audio
4.0 Surround output to Front and Rear speakers
surround41:CARD=DAC,DEV=0
C5D Amp DAC, USB Audio
4.1 Surround output to Front, Rear and Subwoofer speakers
surround50:CARD=DAC,DEV=0
C5D Amp DAC, USB Audio
5.0 Surround output to Front, Center and Rear speakers
surround51:CARD=DAC,DEV=0
C5D Amp DAC, USB Audio
5.1 Surround output to Front, Center, Rear and Subwoofer speakers
surround71:CARD=DAC,DEV=0
C5D Amp DAC, USB Audio
7.1 Surround output to Front, Center, Side, Rear and Woofer speakers
iec958:CARD=DAC,DEV=0
C5D Amp DAC, USB Audio
IEC958 (S/PDIF) Digital Audio Output
dmix:CARD=DAC,DEV=0
C5D Amp DAC, USB Audio
Direct sample mixing device
dsnoop:CARD=DAC,DEV=0
C5D Amp DAC, USB Audio
Direct sample snooping device
hw:CARD=DAC,DEV=0
C5D Amp DAC, USB Audio
Direct hardware device without any conversions
plughw:CARD=DAC,DEV=0
C5D Amp DAC, USB Audio
Hardware device with all software conversions
因此 DAC 识别正确。
朋友们，有什么建议吗？抱歉我的英语不好 ;)
答案1
我在 Ubuntu 14.04 中使用 C5D 没有任何问题。我的 PulseAudiodaemon.conf有以下更改，您可以尝试看看这些更改是否能解决您的问题：
default-sample-format = s24le
default-sample-rate = 48000