Sound - ALSA volume too low

[bedfellow]

I have Google assistant running on Armbian on an Orange Pi Lite headless system. The sound output is via a USB sound card, as the Orange Pi Lite does not have n audio jack, but the volume is too low, even with volume set to max on alsamixer. I've been trying to figure out how to enable pre-amp, but have been unsuccessful. The current asoundrc is:

pcm.!default {
 type asym
 capture.pcm "mic"
 playback.pcm "speaker"
}
pcm.mic {
 type plug
 slave {
 pcm "hw:0,0"
 format S16_LE
 }
}
pcm.speaker {
 type plug
 slave {
 pcm "hw:2,0"
 }
}

 

The only options in alsamixer are those pictured below and even with the volume at max, the output is too low. PCM does not appera to make any difference. I know that the USB card and speaker combination are capable of more, so I suspect it to be an ALSA issue. Any ideas on how I can enable pre-amp or otherwise increase the volume?

 

[bedfellow]

I've figured it out. It's nothing to do with Alsa, rather Google Assistant has the ability to control volume, i.e. "OK Google, turn it to 10"