Comment 3 for bug 1033996

snd-intel8x0 only support stereo and does not support mono

can you post the pulseaudio log?

1 card(s) available.
    index: 0
 name: <alsa_card.pci-0000_00_1f.5>
 driver: <module-alsa-card.c>
 owner module: 4
 properties:
  alsa.card = "0"
  alsa.card_name = "Intel ICH5"
  alsa.long_card_name = "Intel ICH5 with AD1981B at irq 17"
  alsa.driver_name = "snd_intel8x0"
  device.bus_path = "pci-0000:00:1f.5"
  sysfs.path = "/devices/pci0000:00/0000:00:1f.5/sound/card0"
  device.bus = "pci"
  device.vendor.id = "8086"
  device.vendor.name = "Intel Corporation"
  device.product.name = "82801EB/ER (ICH5/ICH5R) AC'97 Audio Controller"
  device.form_factor = "internal"
  device.string = "0"
  device.description = "Built-in Audio"
  module-udev-detect.discovered = "1"
  device.icon_name = "audio-card-pci"
 profiles:
  output:analog-stereo: Analog Stereo Output (priority 6000)
  output:analog-stereo+input:analog-stereo: Analog Stereo Duplex (priority 6060)
  output:iec958-stereo: Digital Stereo (IEC958) Output (priority 5500)
  output:iec958-stereo+input:analog-stereo: Digital Stereo (IEC958) Output + Analog Stereo Input (priority 5560)
  input:analog-stereo: Analog Stereo Input (priority 60)
  off: Off (priority 0)
 active profile: <output:iec958-stereo+input:analog-stereo>
 sinks:
  alsa_output.pci-0000_00_1f.5.iec958-stereo/#0: Built-in Audio Digital Stereo (IEC958)
 sources:
  alsa_output.pci-0000_00_1f.5.iec958-stereo.monitor/#0: Monitor of Built-in Audio Digital Stereo (IEC958)
  alsa_input.pci-0000_00_1f.5.analog-stereo/#1: Built-in Audio Analog Stereo
 ports:
  analog-output-headphones;output-amplifier-on: Headphones / Amplifier (priority 9010, available: unknown)
   properties:

  analog-output-headphones;output-amplifier-off: Headphones / No Amplifier (priority 9000, available: unknown)
   properties:

  analog-output-mono;output-amplifier-on: Analog Mono Output / Amplifier (priority 5010, available: unknown)
   properties:

  analog-output-mono;output-amplifier-off: Analog Mono Output / No Amplifier (priority 5000, available: unknown)
   properties:

  analog-output-lfe-on-mono;output-amplifier-on: LFE on Separate Mono Output / Amplifier (priority 4010, available: unknown)
   properties:

  analog-output-lfe-on-mono;output-amplifier-off: LFE on Separate Mono Output / No Amplifier (priority 4000, available: unknown)
   properties:

  analog-input-microphone;input-microphone-1: Microphone / Microphone 1 (priority 8720, available: unknown)
   properties:

  analog-input-microphone;input-microphone-2: Microphone / Microphone 2 (priority 8719, available: unknown)
   properties:

  analog-input-linein: Line In (priority 8100, available: unknown)
   properties:

  analog-input: Analog Input (priority 8000, available: unknown)
   properties:

  analog-input-video: Video (priority 7000, available: unknown)
   properties:

  iec958-stereo-output: Digital Output (S/PDIF) (priority 0, available: unknown)
   properties: