configure raspberrypi music server file
-----------------------------------------------------------
Debian GNU/Linux comes with ABSOLUTELY NO WARRANTY, to the extent
permitted by applicable law.
Last login: Thu Dec  4 02:06:12 2025 from 192.168.1.5
pi@raspberrypi:~ $ cat /boot/firmware/config.txt
# For more options and information see
# http://rptl.io/configtxt
# Some settings may impact device functionality. See link above for details

# Uncomment some or all of these to enable the optional hardware interfaces
enable i2s
dtparam=i2c_arm=on
dtparam=i2s=on
dtparam=spi=on

# Enable audio (loads snd_bcm2835)
#dtparam=audio=on

# Additional overlays and parameters are documented
# /boot/firmware/overlays/README

# Automatically load overlays for detected cameras
#camera_auto_detect=1

# Automatically load overlays for detected DSI displays
#display_auto_detect=1

# Automatically load initramfs files, if found
#auto_initramfs=1

# Enable DRM VC4 V3D driver
#dtoverlay=vc4-kms-v3d
max_framebuffers=2

# Don't have the firmware create an initial video= setting in cmdline.txt.
# Use the kernel's default instead.
#disable_fw_kms_setup=1

# Run in 64-bit mode
#arm_64bit=1

# Disable compensation for displays with overscan
#disable_overscan=1

# Run as fast as firmware / board allows
#arm_boost=1

[cm4]
# Enable host mode on the 2711 built-in XHCI USB controller.
# This line should be removed if the legacy DWC2 controller is required
# (e.g. for USB device mode) or if USB support is not required.
#otg_mode=1

[cm5]
#dtoverlay=dwc2,dr_mode=host

[pi4]
# Enable DRM VC4 V3D driver on top of the dispmanx display stack
#dtoverlay=vc4-fkms-v3d
max_framebuffers=2



[all]

dtoverlay=hifiberry-dac,slave=true
#dtoverlay=hifiberry-dac8
#dtoverlay=hifiberry-dacplus
#dtoverlay=hifiberry-dacplus-std
#dtoverlay=hifiberry-dacplus
#dtoverlay=hifiberry-dacplus-pro
dtoverlay=hifiberry-digi,slave=true
#dtoverlay=hifiberry-digi-pro
initramfs initrd.img-4.19.97-v7+-overlay

 I am using Hifi berry digi daughter board and getting spdif out.
 this is configure for sound device. 
 this is one of example. by Kenji Mizushima
 OS is RaspbianOS Nightly 

 and mpd.conf show next
 
----------------------------------------------------------------
 pi@raspberrypi:~ $ cat /etc/mpd.conf
music_directory "/var/lib/mpd/music"
playlist_directory "/var/lib/mpd/playlists"
db_file "/var/lib/mpd/database"
#log_file "/var/log/mpd/mpd.log"
#pid_file "/var/run/mpd/pid"
#state_file "/mnt/dietpi_userdata/.mpd_cache/state"
#sticker_file "/mnt/dietpi_userdata/.mpd_cache/sticker.sql"

#user "mpd" #Set via service to allow for mpd user to use assigned groups "audio" and "dietpi"
#group "dietpi" #Set via service to allow for mpd user to use assigned groups "audio" and "dietpi"
user             "mpd"
group            "audio"
bind_to_address "0.0.0.0"

port "6600"
log_level "default"
#gapless_mp3_playback "yes"
# save_absolute_paths_in_playlists "no"
metadata_to_use "artist,album,title,track,name,genre,date"
#auto_update "yes"
#auto_update_depth "3"

 follow_outside_symlinks "yes"
 follow_inside_symlinks "yes"

 zeroconf_enabled "yes"
 zeroconf_name "raspberrypi"

#password "password@read,add,control,admin"
#default_permissions "read,add,control,admin"

input {

plugin "curl"
#proxy "proxy.isp.com:8080"
#proxy_user "user"
#proxy_password "password"

}

connection_timeout "30"
max_connections "20"
max_playlist_length "81920"
max_command_list_size "81920"
max_output_buffer_size "81920"
audio_buffer_size "4096"
filesystem_charset "UTF-8"
#audio_output_format "44100:16:2"
#id3v1_encoding "UTF-8"

#Audio Output / Processing

#Disabled to allow native DSD output
# replaygain "track"
# replaygain_preamp "8"
 volume_normalization "yes"
 
 #buffer_before_play "10%"
filter {
    plugin "volume"
    name "software volume"
}
#######################################################################
#resampler {
#		plugin "soxr"
#		               quality "very high"
#                              threads "0"
resampler {
	plugin         "soxr"
	quality        "custom"
	precision      "16"
	phase_response "50"
	passband_end   "91.3"
	stopband_begin "100"
	attenuation    "0"
	flags          "0"

					  }
#######################################################################
playlist_plugin {
    name "m3u"
        enabled "true"
		       }
########################################################################
decoder {
plugin "wildmidi"
enabled "no"
}


decoder {
plugin "ffmpeg"
enabled "yes"
}

input {
plugin "curl"
}


######################################################################

# audio_output {

#        type            "alsa"
#        name            "SPDIF"
#        device          "hw:SPDIF,0"
#        mixer_type      "software"
 #         dop             "yes"        
  # audio_output_format  "44100:16:2"
#}



#audio_output {
#type "alsa"
#name "DIY PCM5102a"
#device "hw:Pcm5102a,0"
#mixer_type "software"
#format "*:32:2"
#replay_gain_handler "software"
#dop "yes"
#}


audio_output {

type "alsa"
name "Hifiberry-dig"
device "hw:0,0"
mixer_type "software"
dop "yes"
format "44100:16:2" 
}

-------------------------------------
 this is my case .by Kenji Mizushima