Rpi2 Non Linear volume scaling with USB DAC

[spd_ltd]

I have an Rpi2 with a completely fresh install of OSMC using a Plugable brand USB audio adapter ( C-Media HS 100B Chip). My problem is the volume scaling is very non-linear, the bottom 30% of the scale is basically silence, 30-50% is what 0-10% should be, and then from 50% to 100% is the remainder of the scale.

Is there any way to adjust the linearity of the volume system?

I switched to OSMC from RuneAudio, and with Rune on this exact hardware the volume scaling was very good and usable,

[Tom_Doyle]

Hi,

You could try installing alsa-utils:

@sam_nazarko

sudo apt-get install alsa-utils

And then run alsamixer you will see there is a volume setting for the DAC. This is independent of the Pi sink. Note you cannot adjust the Pi sink volume via alsamixer unless you load the ALSA module but this is not ideal.

Then run alsactl store to save your settings

S

[spd_ltd]

One of the first things i did was install and run alsamixer (because i had to do this under Rune as well to get the audio gain to a decent level.

But the non-linearity is still there even with the adjustment in ALSA.

[Tom_Doyle]

Hi,

Sorry but I don’t use a usb dac myself, so I can’t help any further. But I’ve notified another member of the team, which I believe does.

Thanks Tom.