I have installed Debian 10 on a laptop and on a desktop. I am trying to use a Wantek USB headset (earphones + microphone). On both computers I observe the same bizarre failures:
- The earphones play the Skype ringtones, but no other sound from Skype or internet.
- The microphone passes the online microphone test https://www.onlinemictest.com/ , but not the Skype call test.
Checking parameters on Alsamixer, and installing firmware-linux-nonfree do not help. Both computers work well if I plug a non-USB headset with two coaxial connectors (one for microphone, one for earphones). The headset works well with Ubuntu 18.04 on another laptop.
Any ideas on explaining these symptoms, and curing the disease?