Unmute a microHAM DigiKeyer II on Linux

I’m currently playing around with a microHAM DigiKeyer II and my Ubuntu 20.04 ham radio PC. When I plug in the DK2, there is no RX audio available, although the sound device is recognized by Ubuntu and all the other features of the DK2 work perfectly. To save you some of the hours that I needed to find the cause, here is my current insight into the problem: capturing is disabled by default for the Mic input in ALSA.

the Mic is not used for capturing by default

Since I’m not using the Mic input, but only the Line input, this was definitely not the first thing to check. The solution is to make the Mic also a capturing device:

amixer -c <cardid> set Mic cap

now the Mic is also used for capturing

Unfortunately ALSA does not remember this setting and I have to do this every time the device is plugged in (or the PC is restarted…). I found no way yet to make this happen automatically. All my hope is on askubuntu.com for now.

73!