Turntable to Sonos, Bose, Bluetooth or internet radio with Raspberry Pi

Create an internet radio stream that allows for streaming your records to your Smart Home Audio System or any other internet radio capable endpoint.

TLDR

1. Set audio device to be streamed in config/darkice.cfg file.

   ...
   device          = plughw:3,0 # Audio device for the audio input
   ...

   See section Persistent audio device number for details about determining your audio device.

2. Start docker container.

   sudo docker compose up

The numbering of the audio devices is not deterministic and changes randomly on reboot.

Concept

The audio systems in modern households are changing drastically and use technologies like Bluetooth or wireless streaming. Additionally, physical connectors are getting removed from the audio equipment. The missing connectors make it harder to connect your record player and listen to your favorite records. This project tackles the problem through the creation of a live internet radio stream in the local network from the current playing record. The internet radio stream can be consumed by any internet radio compatible endpoint in the network. E.g. you can add the created internet radio stream to your smart home audio system from Sonos or Bose Home Audio as well as any other Bluetooth sound system or computer.

Disclaimer

There are already a couple of projects describing a similar approach see section Inspiration. This project attempts to simplify the setup of such an internet streaming service. The resilience is increased through dockerization.
The presented solution doesn't claim to be the audiophile's choice. Nevertheless it creates a suitable solution for connectivity problems with modern audio systems.
It can also be an alternative to expensive solutions like the Sonos Amp or the Bose Music Amplifier.

Setup and configuration

Architecture

The pipeline begins with the record player which is connected to the USB audio interface (see architecture overview above). The analog signal from the current playing record travels through the USB audio interface into the Raspberry Pi. The program Darkice encodes the analog audio signal into a digital audio signal according to your configuration and sends it to a streaming media server. The streaming media server in this setup is Icecast. It creates an internet radio station in your private network. You can listen to it on any device that allows for a connection with an internet radio stream.
To create a similar set up the following steps need to be completed:

1. Organize Hardware.
2. Prepare Raspberry Pi.
3. Install required software.
4. Make number of used audio device persistent.
5. Configure Darkice.
6. Start the container.
7. Test the internet radio stream

Hardware

1. Record player with stereo out.
2. USB Audio interface with phono preamp e.g.:
   1. Behringer U-PHONE UFO202 (tested).
   2. If your record player has a build in phono preamp or you are using an external phono you can also use audio boards from HifiBerry (not tested).
3. Raspberry Pi e.g.:
   1. Raspberry Pi 4 2GB Ram (tested).
   2. Other versions should also work.
4. Audio System eg.:
   1. Sonos including Sonos App (tested).
   2. Any Bluetooth speaker plus internet radio app e.g. TuneIn (tested) or similar.
   3. Bose Home Audio (not tested) including Bose Music APP (not tested).

Example Hardware Costs:

Hardware	Price
Raspberry Pi 4 B 2GB	40,00 €
Power Supply	10,00 €
SD Card 16GB	10,00 €
Case	15,00 €
USB Audio Interface	24,00 €
Total:	99,00 €

Prepare Raspberry Pi

Install a linux operating system of you choice e.g.:

1. Debian (not tested).
2. Ubuntu (not tested).
3. CentOS (not tested).
4. Arch (tested).

Comments:

1. I used arch linux for my setup as I like the rolling-release approach. If you are new to linux and or to Raspberry Pi I would recommend to start with a debian based system like Debian or Ubuntu as the explanations are mostly very comprehensible.
2. If you don't know how to access the your Raspberry Pi remotely with SSH the following guide might give you a good starting point Connect to your Raspberry Pi with ssh. I would like to encourage you to research this part on your own and keep following this guide after you have access to your Raspberry Pi's terminal.

Install required software

Required programs and packages:

• Alsa: API for audio device drivers. No installation required as alsa is part of the Linux Kernel.
• Docker Engine: Program that allows you to run docker containers on your system. Please follow the installation guide from the docker homepage.
• Docker Compose: Tool for defining and running docker containers. Please follow the installation guide from the docker homepage.
• git: Please follow the installation guide from git.

Persistent audio device number

To configure our internet radio stream it is required to inform Darkice about the source of the audio signal that needs to be encoded. The command aplay -l displays a list of known audio devices.

sudo aplay -l

# Example output:
**** List of PLAYBACK Hardware Devices ****
card 0: Headphones [bcm2835 Headphones], device 0: bcm2835 Headphones [bcm2835 Headphones]
  Subdevices: 8/8
  Subdevice #0: subdevice #0
  Subdevice #1: subdevice #1
  Subdevice #2: subdevice #2
  Subdevice #3: subdevice #3
  Subdevice #4: subdevice #4
  Subdevice #5: subdevice #5
  Subdevice #6: subdevice #6
  Subdevice #7: subdevice #7
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
card 3: CODEC [USB Audio CODEC], device 0: USB Audio [USB Audio]
  Subdevices: 1/1
  Subdevice #0: subdevice #0

The example output displays 4 audio cards available on the Raspberry Pi. Relevant for the internet radio stream program is card 3 as it is the audio interface that is connected to the record player. Unlike card 1 card 3 has only one subdevice. Darkice can be configured to listen to card 3 and subdevice 0 by editing the line starting with device in config/darkice.cfg:

...
device          = plughw:3,0 # Audio device for the audio input
...

The 3 of plughw:3,0 represents the card number and the 0 the subdevice. If you start the docker container now your stream would work until the next restart of the Raspberry Pi. Unfortunately alsa is indexing the available audio devices randomly on every reboot. In order to make the system reliable it is necessary to make the numbering of the audio interface persistent. This can be done in various ways as described here for arch linux. One approach to resolve this is to set the card number explicitly in the alsa configuration with the help of the kernel modules.To determine the kernel module used by the audio device the record player is connected to follow the steps described below:

1. Unplug the audio device.

2. Restart the Raspberry Pi.

3. List kernel modules. They are listed in the first column of output.

   lsmod | grep snd
   
   # Example output
   snd_bcm2835            28672  0

4. Connect the audio device.

5. List the kernel modules again.

   # Example output
   snd_usb_audio         319488  0
   snd_usbmidi_lib        36864  1 snd_usb_audio
   snd_hwdep              20480  1 snd_usb_audio
   snd_rawmidi            45056  1 snd_usbmidi_lib
   snd_bcm2835            28672  0
   snd_seq_device         20480  1 snd_rawmidi
   mc                     61440  4 videodev,snd_usb_audio,videobuf2_v4l2,videobuf2_common

The USB audio device is using the module snd_usb_audio. For the sake of simplicity configure alsa such that the USB audio device is the last card of the connected cards by editing /etc/modprobe.d/alsa-base.conf and set the index of the card using the module snd_usb_audio to 3:

options snd_usb_audio index=3

The persistence of the card number can be tested by rebooting a couple of times and checking the numbering of the audio interface after each reboot with the command sudo aplay -l. If your card number is always the same keep on with the configuration of Darkice.

Configure Darkice

Now it is possible to configure Darkice such that it will keep functioning after restarts by editing config/darkice.cfg:

...
device          = plughw:3,0 # Audio device for the audio input
...

Start Container

Last but not least the internet radio streaming container can be started:

sudo docker compose up

This will build the image and start the container. It is configured such that it restarts anytime the host system is restarted.

Test the internet radio stream

1. Navigate with your browser to http://<local ip address of raspberry pi>:8000 e.g. http://192.168.178.43:8000 to check if Icecast is up and running. Here you will also see information about your Darkice encoding.

2. Try to listen to your record.
   1. Configure a web radio player and point it to your stream. Your Stream url is http://<local ip address of raspberry pi>:8000/turntable.mp3 e.g. http://192.168.178.43:8000/turntable.mp3:
      1. Add an Internet radio station to Sonos.
      2. Add custom url to TuneIn.
   2. Start a record on your turntable. The encoding of Darkice causes a slight delay of a few seconds. Be patient!

Have fun and enjoy your favorite records anywhere in your household!

Thanks to

Inspirations

• darkice-libaacplus-rpi-guide by coreyk
• USB-Turntables-to-Sonos-with-RPi by basdp
• Docker Conatiner Audio by leimao

Icons used

• Vinyl Icons erstellt von Pavel Kozlov - Flaticon
• Speaker icons created by Smashicons - Flaticon
• Raspberry Pi icons created by Freepik - Flaticon
• Laptop icons created by Freepik - Flaticon
• Audio icons created by Andrejs Kirma - Flaticon