TOM, VA3TS sent me this note about setting up the alsa sound mixer
When adjusting volume with alsamixer, be sure to turn off the automatic gain control. This is tricky to do but it will solve the “volume too high” problem.
1. open alsamixer from the command line
2. F6 to select the sound device. For me it is C-media USB headphone set.
3. Use left/right arrow to highlite “Auto Gain Control”
4. Press m key to turn Auto Gain Control off (note it changes to [Off] in the “Item:” list above
5. Use right/left arrow to highlite the “Mic CAPTURE” colume.
6. Use up/down arrow to adjust the mic level. Mine is about 30 for best audio
7. Now monitor the Direwolf window and watch for audio levels about 30-50
HINT: If you started Direwolf with it's coloring enabled and now all your
console text is blinking, you can use the command "tput reset" to
clear things out. Better to start with direwolf -t 0