2015-3-30 上午12:22 於 "David Martinez" david@sojournmusic.net 寫道：

Label says PiFi DAC+. v2.0

I'll need to look up how to apply the patch. I'm not familiar with how to

do it.

This look like driver bug since capabilities should be pvolume instead of volume if your sound card are half duplex

Simple mixer control 'PCM',0 Capabilities: volume penum Playback channels: Front Left - Front Right Capture channels: Front Left - Front Right Limits: 0 - 215 Front Left: 172 [80%] Front Right: 172 [80%]

Simple mixer control 'Playback',0 Capabilities: volume penum Playback channels: Front Left - Front Right Capture channels: Front Left - Front Right Limits: 0 - 1 Front Left: 0 [0%] [-6.00dB] Front Right: 0 [0%] [-6.00dB]

Simple mixer control 'Playback Boost',0 Capabilities: volume penum Playback channels: Front Left - Front Right Capture channels: Front Left - Front Right Limits: 0 - 1 Front Left: 0 [0%] [0.00dB] Front Right: 0 [0%] [0.00dB]

...

...

I'll check HiFiBerry's site and see if I can get it.

https://www.hifiberry.com/dacplus/

What is the label on the black DAC chip ?

Aplay/Arecord output !!--------------------

APLAY

**** List of PLAYBACK Hardware Devices **** card 0: sndrpihifiberry [snd_rpi_hifiberry_dacplus], device 0: HiFiBerry

DAC HiFi pcm512x-hifi-0 []

...

Subdevices: 1/1 Subdevice #0: subdevice #0

ARECORD

**** List of CAPTURE Hardware Devices ****

Seem half duplex