[SOLVED] volume control bug when turning off DAC

[vext01]

OK. Music is playing:

Code:

edd@moode:~ $ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: AUDIO [LOXJIE AUDIO], device 0: USB Audio [USB Audio]
 Subdevices: 0/1
 Subdevice #0: subdevice #0
card 1: vc4hdmi0 [vc4-hdmi-0], device 0: MAI PCM i2s-hifi-0 [MAI PCM i2s-hifi-0]
 Subdevices: 1/1
 Subdevice #0: subdevice #0
card 2: vc4hdmi1 [vc4-hdmi-1], device 0: MAI PCM i2s-hifi-0 [MAI PCM i2s-hifi-0]
 Subdevices: 1/1
 Subdevice #0: subdevice #0

Code:

edd@moode:~ $ amixer scontrols
Simple mixer control 'LOXJIE AUDIO ',0
Simple mixer control 'LOXJIE AUDIO ',1

And for good measure:

Code:

edd@moode:~ $ amixer controls                                                                                                  
numid=6,iface=CARD,name='LOXJIE Internal Clock Validity'
numid=2,iface=MIXER,name='LOXJIE AUDIO  Playback Switch'
numid=3,iface=MIXER,name='LOXJIE AUDIO  Playback Switch',index=1
numid=4,iface=MIXER,name='LOXJIE AUDIO  Playback Volume'
numid=5,iface=MIXER,name='LOXJIE AUDIO  Playback Volume',index=1
numid=1,iface=PCM,name='Playback Channel Map'

and:

Code:

edd@moode:~ $ amixer
Simple mixer control 'LOXJIE AUDIO ',0
 Capabilities: pvolume pswitch
 Playback channels: Front Left - Front Right
 Limits: Playback 0 - 127
 Mono:
 Front Left: Playback 126 [99%] [-1.00dB] [on]
 Front Right: Playback 126 [99%] [-1.00dB] [on]
Simple mixer control 'LOXJIE AUDIO ',1
 Capabilities: pvolume pvolume-joined pswitch pswitch-joined
 Playback channels: Mono
 Limits: Playback 0 - 127
 Mono: Playback 127 [100%] [0.00dB] [on]

I'm not familiar with ALSA, but do I see it right that the DAC expose these two volume controls, one that can attenuate individual stereo channels, and another which can't?

Moode is adjusting mixer control #0. I can adjust the volume in the web UI and see that value change.

For example Moode web UI volume 30:

Code:

 Front Left: Playback 96 [76%] [-31.00dB] [on]
 Front Right: Playback 96 [76%] [-31.00dB] [on]

Moode web UI volume 60:

Code:

 Front Left: Playback 114 [90%] [-13.00dB] [on]
 Front Right: Playback 114 [90%] [-13.00dB] [on]

Not sure why the percentages don't agree there...

One theory then would be that mixer control #1 is the actual hardware control of the DAC (and #0 just attenuates individual channels). But the volume display on the LCD screen on the DAC reads 26 (out of 60) and ALSA displays the mixer control #1 volume as:

Code:

 Mono: Playback 127 [100%] [0.00dB] [on]

Which again doesn't make sense. 26 isn't full blast, as this output would suggest. Turning the volume down using the physical knob on the unit doesn't vary any ALSA mixer output.

Still unsure why fixed volume in Moode doesn't work at all. Many mysteries.

Let me know if there's any other output that would help.