(I sent this first to alsa-user and was instructed to send it to alsa-devel, as well.)
With a new OS installation on a pre-existing machine, some of the USB audio devices now have only 1.00 dB of playback volume adjustment, which of course is not enough to be terribly useful.
The affected USB devices show up as "Audio Advantage MicroII" in the output of "aplay -L". From LSB, they show up as these:
Bus 001 Device 004: ID 0d8c:0103 C-Media Electronics, Inc. CM102-A+/102S+ Audio Controller Bus 001 Device 003: ID 0d8c:0103 C-Media Electronics, Inc. CM102-A+/102S+ Audio Controller
I just installed Devuan Ascii on the machine. It's running kernel 4.9.0-8-amd64 and alsa-utils version 1.1.3-1. Doing "amixer -c 1 contents" or "amixer -c 2 contents" shows this for playback volume:
numid=3,iface=MIXER,name='PCM Playback Volume' ; type=INTEGER,access=rw---R--,values=2,min=0,max=255,step=0 : values=0,0 | dBminmax-min=-1.00dB,max=0.00dB
and
numid=3,iface=MIXER,name='PCM Playback Volume' ; type=INTEGER,access=rw---R--,values=2,min=0,max=255,step=0 : values=77,77 | dBminmax-min=-1.00dB,max=0.00dB
It looks like I'm running kernel 4.9.0-8-amd64 and alsa-utils version 1.1.3-1.
Using alsamixer to run the controls from end to end, I cannot perceive any difference in volume level.
In contrast, the other device I use (either HDA Intel or HDA NVidia) has around a 60dB range according to amixer, and running the control in alsamixer from end to end has a huge range of gain.
Previously, the exact same hardware was running Debian 7/Wheezy and then Slackware 14.2. With both those operating systems, the USB sound devices had a very adequate volume control range, certainly a whole lot more than 1dB.
Being as the USB sound devices are the ones my wife uses, I'd be extremely grateful if somebody could point me a to way (if one exists) to a usefully greater range of volume control. Any suggestions?
Assuming this qualifies as a bug, what channel should I use to report it so it can be queued to be fixed?
Thanks,
Robert