[alsa-devel] snd-usb-audio issues??

[Richard Storer]

My Sound Blaster is assigned to card1 (-c1) because the Pi already has
built-in audio playback capability.

root at raspberrypi:~# amixer scontents -c1
Simple mixer control 'PCM',0
  Capabilities: pvolume pvolume-joined pswitch pswitch-joined penum
  Playback channels: Mono
  Limits: Playback 0 - 100
  Mono: Playback 85 [85%] [-7.50dB] [on]
Simple mixer control 'Mic',0
  Capabilities: cvolume cvolume-joined penum
  Capture channels: Mono
  Limits: Capture 0 - 15
  Mono: Capture 9 [60%] [13.50dB]
Simple mixer control 'CMSS LED',0
  Capabilities: pswitch pswitch-joined penum
  Playback channels: Mono
  Mono: Playback [off]
Simple mixer control 'Power LED',0
  Capabilities: pswitch pswitch-joined penum
  Playback channels: Mono
  Mono: Playback [on]

Richard S.

On 14/04/2014, Clemens Ladisch <clemens at ladisch.de> wrote:
> Richard Storer wrote:
>> My first issue is for some reason booting Linux with my device already
>> attached to the USB port produces no audio output, however capture is
>> functioning.
>> I've tried mute, unmute via alsamixer but it seems like the amplifier
>> circuit inside hasn't turned itself on properly.
>> The cure for this (and 100% reproducible) would be to unplug / replug
>> the USB cable or simply connect to USB after Linux has fully loaded.
>
> Are there any mixer controls that have a different value in these
> situations?  (See the output of "amixer scontents" for your device.)
>
>> While Line-In capture does function on this device the signal levels
>> are extremely low.
>> Unfortunately there is no Line-In mixer control for my device
>
> What is the output of "amixer scontents" for your device?
>
>
> Regards,
> Clemens
>