Hi Matt!

I have had an AudioInjector stereo unit working really well for some time in my Raspberry Pi 4b unit.  I use the RCA-IN connections to pass TV sound output, through the Raspberry Pi RCA-OUTS into a stereo amplifier.  We also playback music from the Raspberry Pi using Sqeezebox. From what I remember, to enable multiple streams of audio to be played simultaneously, we utilize the Dmix plugin in ALSA.

For some reason, I now have very diminished sound from the Raspberry Pi RCA-Inputs, and only when listening with headphones from the Headphone jack on the AudioInjector.  I'm getting NO sound from the RCA OUTs.  I get normal, full sound from the AudioInjector Headphone jack when playing music on the Raspberry Pi Apps (Squeezebox).   But no RCA Output Sound from Raspberry Pi Apps. 

I've gone through the setup/test scripts again and still not able to get sound to normalize.  ALSA does detect the Stereo Card: 

pi@LivingRoomPi:~ $ aplay -l
**** List of PLAYBACK Hardware Devices ****
card 0: audioinjectorpi [audioinjector-pi-soundcard], device 0: AudioInjector audio wm8731-hifi-0 [AudioInjector audio wm8731-hifi-0]
  Subdevices: 0/1
  Subdevice #0: subdevice #0


And  I ran the RCA Thru script successfully:
pi@LivingRoomPi:~ $ alsactl --file /usr/share/doc/audioInjector/asound.state.RCA.thru.test restore
Found hardware: "audioinjector-p" "" "" "" ""
Hardware is initialized using a generic method

And the Output Mixer HiFi on command:

pi@LivingRoomPi:~ $ sudo amixer set 'Output Mixer HiFi' on
Simple mixer control 'Output Mixer HiFi',0
  Capabilities: pswitch pswitch-joined
  Playback channels: Mono
  Mono: Playback [on]


When I check the ALSA Mixer settings, I have all settings turned up to 100 and unmuted With the exception of output mixer line bypass is off. When I turn it on the slight amount of sound that I am able to hear from the AudioInjector Headphone Jackis diminished. 

Could my card be malfunctioning?   It almost seems as if something's not turned up all the way (Oh, yes the knobs on the side of the AudioInjector are turned all the way up, clockwise),  or muted, but I can't quite figure out where to look next.

Thanks so much for your support!

Michael
Johnson City, TN

/etc/asound.conf  reads:
pcm.!default {
    type            plug
    slave.pcm       "softvol"   #make use of softvol
}

pcm.softvol {
    type            softvol
    slave {
        pcm         "dmix"      #redirect the output to dmix (instead of "hw:0,0")
    }
    control {
        name        "PCM"       #override the PCM slider to set the softvol volume level globally
        card        0
    }
}


/usr/share/alsa/alsa.conf reads:
#
#  ALSA library configuration file
#

# pre-load the configuration files

@hooks [
{
func load
files [
"/etc/alsa/conf.d"
"/etc/asound.conf"
"~/.asoundrc"
]
errors false
}
]

# load card-specific configuration files (on request)

cards.@hooks [
{
func load
files [
{
@func concat
strings [
{ @func datadir }
"/cards/aliases.conf"
]
}
]
}
{
func load_for_all_cards
files [
{
@func concat
strings [
{ @func datadir }
"/cards/"
{ @func private_string }
".conf"
]
}
]
errors false
}
]

#
# defaults
#

# show all name hints also for definitions without hint {} section
defaults.namehint.showall on
# show just basic name hints
defaults.namehint.basic on
# show extended name hints
defaults.namehint.extended on
#
defaults.ctl.card 0
defaults.pcm.card 0
defaults.pcm.device 0
defaults.pcm.subdevice -1
defaults.pcm.nonblock 1
defaults.pcm.compat 0
defaults.pcm.minperiodtime 5000 # in us
defaults.pcm.ipc_key 5678293
defaults.pcm.ipc_gid audio
defaults.pcm.ipc_perm 0660
defaults.pcm.dmix.max_periods 0
defaults.pcm.dmix.rate 441000
defaults.pcm.dmix.format "unchanged"
defaults.pcm.dmix.card defaults.pcm.card
defaults.pcm.dmix.device defaults.pcm.device
defaults.pcm.dsnoop.card defaults.pcm.card
defaults.pcm.dsnoop.device defaults.pcm.device
defaults.pcm.front.card defaults.pcm.card
defaults.pcm.front.device defaults.pcm.device
defaults.pcm.rear.card defaults.pcm.card
defaults.pcm.rear.device defaults.pcm.device
defaults.pcm.center_lfe.card defaults.pcm.card
defaults.pcm.center_lfe.device defaults.pcm.device
defaults.pcm.side.card defaults.pcm.card
defaults.pcm.side.device defaults.pcm.device
defaults.pcm.surround21.card defaults.pcm.card
defaults.pcm.surround21.device defaults.pcm.device
defaults.pcm.surround40.card defaults.pcm.card
defaults.pcm.surround40.device defaults.pcm.device
defaults.pcm.surround41.card defaults.pcm.card
defaults.pcm.surround41.device defaults.pcm.device
defaults.pcm.surround50.card defaults.pcm.card
defaults.pcm.surround50.device defaults.pcm.device
defaults.pcm.surround51.card defaults.pcm.card
defaults.pcm.surround51.device defaults.pcm.device
defaults.pcm.surround71.card defaults.pcm.card
defaults.pcm.surround71.device defaults.pcm.device
defaults.pcm.iec958.card defaults.pcm.card
defaults.pcm.iec958.device defaults.pcm.device
defaults.pcm.modem.card defaults.pcm.card
defaults.pcm.modem.device defaults.pcm.device
# truncate files via file or tee PCM
defaults.pcm.file_format "raw"
defaults.pcm.file_truncate true
defaults.rawmidi.card 0
defaults.rawmidi.device 0
defaults.rawmidi.subdevice -1
defaults.hwdep.card 0
defaults.hwdep.device 0
defaults.timer.class 2
defaults.timer.sclass 0
defaults.timer.card 0
defaults.timer.device 0
defaults.timer.subdevice 0

#
#  PCM interface
#

# redirect to load-on-demand extended pcm definitions
pcm.cards cards.pcm

pcm.default cards.pcm.default
pcm.sysdefault cards.pcm.default
pcm.front cards.pcm.front
pcm.rear cards.pcm.rear
pcm.center_lfe cards.pcm.center_lfe
pcm.side cards.pcm.side
pcm.surround21 cards.pcm.surround21
pcm.surround40 cards.pcm.surround40
pcm.surround41 cards.pcm.surround41
pcm.surround50 cards.pcm.surround50
pcm.surround51 cards.pcm.surround51
pcm.surround71 cards.pcm.surround71
pcm.iec958 cards.pcm.iec958
pcm.spdif iec958
pcm.hdmi cards.pcm.hdmi
pcm.dmix cards.pcm.dmix
pcm.dsnoop cards.pcm.dsnoop
pcm.modem cards.pcm.modem
pcm.phoneline cards.pcm.phoneline

pcm.hw {
@args [ CARD DEV SUBDEV ]
@args.CARD {
type string
default {
@func getenv
vars [
ALSA_PCM_CARD
ALSA_CARD
]
default {
@func refer
name defaults.pcm.card
}
}
}
@args.DEV {
type integer
default {
@func igetenv
vars [
ALSA_PCM_DEVICE
]
default {
@func refer
name defaults.pcm.device
}
}
}
@args.SUBDEV {
type integer
default {
@func refer
name defaults.pcm.subdevice
}
}
type hw
card $CARD
device $DEV
subdevice $SUBDEV
hint {
show {
@func refer
name defaults.namehint.extended
}
description "Direct hardware device without any conversions"
}
}

pcm.plughw {
@args [ CARD DEV SUBDEV ]
@args.CARD {
type string
default {
@func getenv
vars [
ALSA_PCM_CARD
ALSA_CARD
]
default {
@func refer
name defaults.pcm.card
}
}
}
@args.DEV {
type integer
default {
@func igetenv
vars [
ALSA_PCM_DEVICE
]
default {
@func refer
name defaults.pcm.device
}
}
}
@args.SUBDEV {
type integer
default {
@func refer
name defaults.pcm.subdevice
}
}
type plug
slave.pcm {
type hw
card $CARD
device $DEV
subdevice $SUBDEV
}
hint {
show {
@func refer
name defaults.namehint.extended
}
description "Hardware device with all software conversions"
}
}

pcm.plug {
@args [ SLAVE ]
@args.SLAVE {
type string
}
type plug
slave.pcm $SLAVE
}

pcm.shm {
@args [ SOCKET PCM ]
@args.SOCKET {
type string
}
@args.PCM {
type string
}
type shm
server $SOCKET
pcm $PCM
}

pcm.tee {
@args [ SLAVE FILE FORMAT ]
@args.SLAVE {
type string
}
@args.FILE {
type string
}
@args.FORMAT {
type string
default {
@func refer
name defaults.pcm.file_format
}
}
type file
slave.pcm $SLAVE
file $FILE
format $FORMAT
truncate {
@func refer
name defaults.pcm.file_truncate
}
}

pcm.file {
@args [ FILE FORMAT ]
@args.FILE {
type string
}
@args.FORMAT {
type string
default {
@func refer
name defaults.pcm.file_format
}
}
type file
slave.pcm null
file $FILE
format $FORMAT
truncate {
@func refer
name defaults.pcm.file_truncate
}
}

pcm.null {
type null
hint {
show {
@func refer
name defaults.namehint.basic
}
description "Discard all samples (playback) or generate zero samples (capture)"
}
}

#
#  Control interface
#

ctl.sysdefault {
type hw
card {
@func getenv
vars [
ALSA_CTL_CARD
ALSA_CARD
]
default {
@func refer
name defaults.ctl.card
}
}
hint.description "Default control device"
}
ctl.default ctl.sysdefault

ctl.hw {
@args [ CARD ]
@args.CARD {
type string
default {
@func getenv
vars [
ALSA_CTL_CARD
ALSA_CARD
]
default {
@func refer
name defaults.ctl.card
}
}
}
type hw
card $CARD
hint.description "Direct control device"
}

ctl.shm {
@args [ SOCKET CTL ]
@args.SOCKET {
type string
}
@args.CTL {
type string
}
type shm
server $SOCKET
ctl $CTL
}

#
#  RawMidi interface
#

rawmidi.default {
type hw
card {
@func getenv
vars [
ALSA_RAWMIDI_CARD
ALSA_CARD
]
default {
@func refer
name defaults.rawmidi.card
}
}
device {
@func igetenv
vars [
ALSA_RAWMIDI_DEVICE
]
default {
@func refer
name defaults.rawmidi.device
}
}
hint.description "Default raw MIDI device"
}

rawmidi.hw {
@args [ CARD DEV SUBDEV ]
@args.CARD {
type string
default {
@func getenv
vars [
ALSA_RAWMIDI_CARD
ALSA_CARD
]
default {
@func refer
name defaults.rawmidi.card
}
}
}
@args.DEV {
type integer
default {
@func igetenv
vars [
ALSA_RAWMIDI_DEVICE
]
default {
@func refer
name defaults.rawmidi.device
}
}
}
@args.SUBDEV {
type integer
default -1
}
type hw
card $CARD
device $DEV
subdevice $SUBDEV
hint {
description "Direct rawmidi driver device"
device $DEV
}
}

rawmidi.virtual {
@args [ MERGE ]
@args.MERGE {
type string
default 1
}
type virtual
merge $MERGE
}

#
#  Sequencer interface
#

seq.default {
type hw
hint.description "Default sequencer device"
}

seq.hw {
type hw
}

#
#  HwDep interface
#

hwdep.default {
type hw
card {
@func getenv
vars [
ALSA_HWDEP_CARD
ALSA_CARD
]
default {
@func refer
name defaults.hwdep.card
}
}
device {
@func igetenv
vars [
ALSA_HWDEP_DEVICE
]
default {
@func refer
name defaults.hwdep.device
}
}
hint.description "Default hardware dependent device"
}

hwdep.hw {
@args [ CARD DEV ]
@args.CARD {
type string
default {
@func getenv
vars [
ALSA_HWDEP_CARD
ALSA_CARD
]
default {
@func refer
name defaults.hwdep.card
}
}
}
@args.DEV {
type integer
default {
@func igetenv
vars [
ALSA_HWDEP_DEVICE
]
default {
@func refer
name defaults.hwdep.device
}
}
}
type hw
card $CARD
device $DEV
hint {
description "Direct hardware dependent device"
device $DEV
}
}

#
#  Timer interface
#

timer_query.default {
type hw
}

timer_query.hw {
type hw
}

timer.default {
type hw
class {
@func refer
name defaults.timer.class
}
sclass {
@func refer
name defaults.timer.sclass
}
card {
@func refer
name defaults.timer.card
}
device {
@func refer
name defaults.timer.device
}
subdevice {
@func refer
name defaults.timer.subdevice
}
hint.description "Default timer device"
}

timer.hw {
@args [ CLASS SCLASS CARD DEV SUBDEV ]
@args.CLASS {
type integer
default {
@func refer
name defaults.timer.class
}
}
@args.SCLASS {
type integer
default {
@func refer
name defaults.timer.sclass
}
}
@args.CARD {
type string
default {
@func refer
name defaults.timer.card
}
}
@args.DEV {
type integer
default {
@func refer
name defaults.timer.device
}
}
@args.SUBDEV {
type integer
default {
@func refer
name defaults.timer.subdevice
}
}
type hw
class $CLASS
sclass $SCLASS
card $CARD
device $DEV
subdevice $SUBDEV
hint {
description "Direct timer device"
device $DEV
}
}