Audio Personal Computing

Introducing Roon Audio

I’ve been using Plex as my audio player for a while. Noodling around on the Internet looking Raspberry Pi stuff, I stumbled across HiFiBerry and from there Roon Audio. Roon Labs is a spinoff from Meridian of their multi-room digital audio player. These folks have done something right by starting with a client server open architecture which organizes the system as

  1. A music server process
  2. A music management service that builds metadata for your library
  3. A control service that determines what plays where
  4. And endpoints that play content or deliver content to an audio system

They’ve made the endpoint easily embeddable in high fidelity and home theater components. They’ve made the server run as a service so a machine need not be logged in to make your music available. The control runs on Linux, MacOS, and Windows and as iOS and Android applications on phones and tablets.

Where I’m At

I have a two week trial running on my new Mac. In August, I’ll subscribe and build a dedicated Roon Bridge using HiFiBerry parts. This Roon Bridge will replace the AppleTV 3 serving the HiFi. I’ll keep the TV and ChromeCast TOSlinks initially but will likely retire the ChromeCast.

Listening Impressions

It works with less fuss than Plex, a superior user interface, better library material encouraging music discovery, and potentially, state of the art digital audio as a result of removing first-mover constraints from the protocol designs and software architecture. I find Roon very listenable using the iMac’s built in speakers. They image surprisingly well in the near field when playing good source material. The sound is also good through an AppleTV and Parasound P5 built in DAC. This combination sounds less good than the Chrome Cast Audio feeding the same DAC. There seems to be a bit more image via the Chrome Cast than the AppleTV.


  3. tinkering topic area

Interesting Features of Roon

  • Recommendations based on your library content and play history.
  • Who’s on tour that has music in your library
  • If you like this, you might also like recommendations.
  • Interface with Tidal to stream Tidal lossless music like that in your library.
  • Playlist support (Not in Plex)
  • Sample rate conversion and up conversion to device best resolution.
  • Video multi-channel mix down to stereo
  • Equalization and filtering. Each endpoint has a a “FAT channel” in audio mixer jargon.
  • Support for many commercially available endpoints
  • DIY endpoints for computer tinkerers
  • DIY ROCK (Roon Optimized Core Kit) for OEM’s and tinkerers
  • Coming CROCK (containerized Roon optimized core) distributed as a Docker container for tinkerers.


Where I’m Headed

Roon Labs distributes Roon Core versions for Linux, MacOS, and Windows. Roon Core combines the server, the controller, and librarian in a single program that allows you to get started and play music on the local host and any attached audio interfaces. A MacBook or MS Surface Notebook with an AudioQuest Dragon Fly USB DAC is a great introduction to high end audio.

I’m planning to replace the AppleTV with a Raspberry PI running Roon Bridge. This lets Roon server send RAAT audio rather than AirPlay audio to the endpoint. The advantage of using Roon Bridge is that AirPlay requires conversion of audio to 44k/16 bit PCM format while RAAT supports higher sampling rates up to 384k/24 PCM and can stream DSD to those players capable of receiving it. Basically, RAAT is a cousin of GoogleCast Audio and AirPlay with mass-market limitations removed and OEM embedding supported and encouraged.

Building the HiFIBerry Roon Bridge will let me retire the Apple TV3 Eventually, Apple will loose interest in supporting it. I may also be able to retire the Google Chrome Cast audio puck. It works well but runs warm and I expect it will have  a shortened life-span.

Subscription is required

Once the 2 week trial expires, I’ll let the demo account roll over into a paid subscription for $120 per year. Your subscription gives you access to the library metadata that the librarian fetches. The library metadata is rich consisting of cover art, artist profiles, album reviews, album and track classification for genius playing of like material from your library, and more. There may even be liner notes (remember them, if you do, you’re likely a retired moocher like me.).

Your subscription finances metadata library maintenance at Roon Labs and supports on-going software development.

HiFiBerry Build Plans

HiFiBerry makes Raspberry PI audio interface HATS. A HAT is a daughter board that stacks with a Raspberry PI to provide application specific I/O. HiFiBerry makes a number of these with DACS and serial audio interfaces. One, Digi+ provides a transformer isolated serial interface and a TOSlink optical interface. These allow you to connect the Raspberry PI to a high quality home audio digital to analog converter as a serial digital source. The optical version works well as fiber does not cause ground loops and blocks electrical noise.

I’ve priced out the bits. For about $150 US, you can build a Raspberry PI 3 with case, Digi+ daughter board, power supply, and the necessary microSD card for software installation. You need the 2 boards, case, power supply, USB adapter to write the microSD card, and a microSD card. HiFiBerry distributes Roon Bridge as a complete Raspberry PI image ready to run. Download the image and copy it to the microSD card using your favorite block copy utility (dd works for the savvy).

Making a CROCK

Ix Systems is in the process of adding Docker Container support to FreeNAS. Once this project is mature enough to use, I’ll install the Roon ROCK in a container on my FreeNAS file server. This will let me move the library off the iMac but keep Roon for control and playback. FreeNAS will take over content streaming chores. It is a robust Xeon E3 machine with ECC and ZFS storage designed to run continuously. Being punny, Rock in a Docker container becomes a CROCK, containerized Roon optimized core kit.

A developer already has the Docker images available. It is a matter of letting Ix Systems catch up FreeNAS and following the directions.



By davehamby

A modern Merlin, hell bent for glory, he shot the works and nothing worked.