On Thursday, 23 April 2020 20:01:51 BST Jorge Almeida wrote:

> I need the "virtual" card to be the default, so I did this:
> 
> pcm.mbcard{
> type hw
> card PCH
> device 1
> }
> ctl.mbcard{
> type hw
> card 0
> }
> pcm.usbcard{
> type hw
> card CODEC
> device 0
> }
> pcm.output{
> type plug
> slave.pcm "mbcard"
> }
> pcm.input{
> type plug
> slave {
> pcm "usbcard"
> channels 1
> }
> }
> pcm.!default{
> type asym
> playback.pcm "output"
> capture.pcm "input"
> }
> 
> (The microphone is mono, hence the channels entry. I'm not sure it is
> needed.)
> 
> I think this sets the defaults, because:
> --I can record with "arecord -fdat test.wav"
> --I can playback with "aplay test.wav"

I'd think this is a good enough proof your audio setup works at a basic level.  
:-)


> What I cannot do is to coax discord into working. Maybe discord
> doesn't expect ALSA's defaults after all?
> Anyone familiar with discord? (No gamers?)
> 
> Thanks
> 
> Jorge

Applications can be rather particular regarding bitrate, bit sample formats, 
channel configuration and other options.  I understand Firefox wants to have 
48000Hz or it won't play.  So, even if your DAC can do 96000Hz, you may need 
to specify a lower bit rate in the above config.

The mic may also need specifying a particular endianess format and this may 
need to be different if you are using some websocket in FF, Vs the discord app 
directly.  You could try S32_LE or S16_LE and various bit rates.

The idea being to force alsa to use whatever format and rates the application 
may need/want, rather than passing through whatever the hardware is capable 
of.