Hifi audio music over the air

Objectives: play music in the house, from whatever devices, with ease.

1 Sources

2 Output, amp, speakers

2.1 Marantz amp

in the living room, with its 6 loud speakers.

2.2 DONE Airport express in the attic

It needs a speaker?

Maybe I could attach something to it, like a

3 Setup the Raspberry Pie

3.1 RPi with HifiBerry DAC+ pro Hardware Attached on Top DAC

I use the RPi2, which requires less power to run and seems sufficient for the job at hand.

The RPi is USB and ETH attached to the Airport Time Capsule right next to it. No power block, no wifi dropping frames. Less pover consumption.

3.2 System and packages

Raspbian seems OK.

Regarding the post-install config, mostly about deactivating stuff to lower the power consumption: 

# /boot/config.txt
[all]
# should disable wifi, bluetooth and hdmi at boot time, lowering power consumption
dtoverlay=disable-wifi
dtoverlay=disable-bt
hdmi_blanking=2
#dtoverlay=vc4-fkms-v3d
dtoverlay=hifiberry-dacplus

# builtin audio must be deactivated
#dtparam=audio=on

Also, HDMI deactivation could live in another place, so add the following to /etc/rc.local : 

# Disable HDMI 
/usr/bin/tvservice -o

Then, some packages should be installed: 

sudo apt-get update
sudo apt-get upgrade

sudo apt-get pulseaudio pulsemixer pamix shairport 
pulseaudio-module-raop pulseaudio-module-zeroconf cmus mpd mpc

3.3 Airport streaming

Airport works out of the box, using pulseaudio.

3.4 PulseAudio streaming

Pulseaudio remote has to be activated 

systemctl enable avahi-daemon.service
systemctl start avahi-daemon.service

Edit /etc/pulse/default.pa and add these lines:
load-module module-native-protocol-tcp auth-ip-acl=127.0.0.1;192.168.0.0/24 auth-anonymous=1
load-module module-zeroconf-publish