Raspi: minimal transport setup?

[mcgillroy]

Could anybody give me a quick rundown on the minimal requirements for an Raspi-based USB-Audio transport?! My setup is as follows: Macbook/NAS -> ethernet -> transport -> USB-DAC -> powered speakers.

 

Basically I need a Raspberry providing USB-output to the DAC, ideally accepting Airplay and or files served via Mimimserver or similar from the NA/Macbook.

 

Would a Pi Zero suffice or is a normal Raspberry necessary? Tips for bundles (available in Europe) are welcome.

 

Are there any tips with regards to software? Also any tips with regards to enclosures?

 

Thx!  

 

 

[Cebolla]

Minimal requirements given your setup are actually quite straight forward:

 

- A Linux distro for the RPi that supports your particular USB DAC and audio file types. Having said that, it's likely that the you'll be fine with the majority of the latest distros for the RPi if your DAC isn't too unusual in its handling of USB audio and you don't need your DAC  to receive DSD natively, as opposed to via DoP;

 

- Run a UPnP renderer application on the RPi that supports playing the audio file types and resolutions being handled by your particular Minimserver's configuration or similar UPnP media server's configuration. The MPD (Music Player Daemon) audio file player & upmpdcli (a front-end client for MPD) UPnP renderer combination should fulfill most needs as a standard UPnP and OpenHome renderer;

 

- Run an unofficial/'open source' AirPlay audio player software, given that there are no Apple approved AirPlay audio player applications available for the RPi. BTW, no unofficial Airplay audio player applications currently support AirPlay 2 and only the Shairport Sync application supports original AirPlay 1's full audio synchronisation.

 

 

The moOde, Volumio and RuneAudio specialised network audio file player distros come with MPD/upmpdcli as the UPnP renderer and Shairport Sync for AirPlay support, as well as a web browser controller app and many other built-in audio features. For a more DIY approach, to manually install and have full control over configuring & running MPD, upmdpcli & Shairport Sync - use either the bog standard Raspbian Stretch Lite distro or the resource saving DietPi distro instead.

[mcgillroy]

Thx Cebolla - very helpful! Any tips on the HE-side of things: Pi Zero or full Raspberry? The Zero does not seem to come with a USB-A port and would need an adapter from USB-mini.

 

DAC is a Focusrite 6i6. Standard USB , no DSD and none needed.

[skikirkwood]

I would go for a full Raspberry over the Pi Zero. I have 4 or 5 Raspberry Pi 3's in my house driving music to various audio systems. I run both Volumio (I am the main contributor to the Spotify plugin) and piCorePlayer. The sound quality of either distro will be identical.

 

PiCorePlayer is an extremely small distro built on piCore Linux. It leverages the open source software Logitech built for their Squeezebox hardware, discontinued years ago. The software is rock solid, and has a ton of plugins.

 

Volumio is a newer system, built on Node.js, that is a lot of fun to play with, and has an increasingly large number of plugins coming from an active community. There is a paid subscription to MyVolumio, however the base Volumio system is open source and free to use.

 

In both cases you can add a $70 touchscreen to the Pi, and have a great UI in addition to the various mobile phone/tablet apps you can use as a controller. 

 

I would recommend getting two microSD cards, try out both, and see which one you like more. If you do try out Volumio and want to use Spotify make sure to check out the thread on the forum on how to install a patch to get Spotify working correctly.

[bluesman]

Why not drive the DAC directly with the Mac?  

 

If you’re adding the Pi as a second player on your LAN or WLAN, all you need is a player/OS package like Rune or Volumio to both access files directly from your NAS and drive your USB DAC. DietPi is another nice little OS that lets you install any of several players easily and is simple as Pi to set up.

 

The Zero has a USB OTG port, not a standard USB. You need an OTG adapter to use it as you would a regular USB port. I’d use a full size Pi - it has a faster, better processor and more flexibility for audio.

[Cebolla]

4 hours ago, mcgillroy said:

Thx Cebolla - very helpful! Any tips on the HE-side of things: Pi Zero or full Raspberry? The Zero does not seem to come with a USB-A port and would need an adapter from USB-mini.

 

DAC is a Focusrite 6i6. Standard USB , no DSD and none needed.

 

Never used the Pi Zero, though a quick online search suggests all the player software & distros I mentioned should work on it apart from Volumio and it should be ok to use with a USB DAC with an appropriate OTG adapter. You could get one along with a regular RPi and compare them for yourself, given how inexpensive they are. However, as the others have advised, it may not be worth the effort.

 

Interesting that you'll be using the Focusrite Scarlett 6i6 as a 'mere' USB DAC, seeing as it's normally used by musicians as a USB audio interface for their instruments, microphones, etc. Hopefully it is bear minimum supported as a USB DAC on the various distros, though don't expect its internal mixer to be fully controllable, if at all -  so you may not even be able to control its USB DAC volume from the controller app.

[mcgillroy]

37 minutes ago, bluesman said:

Why not drive the DAC directly with the Mac?  

 

 

The Mac sits on a desk on the opposite side of the room. Got Ethernet as wireless streaming never worked reliably.

 

The 6i6 is from my partner who’s a classical musician and uses it to record rehearsals. But since it’s only used in that functionality about once a month and sounds better than the Airport Express we used so far it became our DAC in the study .

 

 

[bluesman]

3 hours ago, mcgillroy said:

 

The Mac sits on a desk on the opposite side of the room. Got Ethernet as wireless streaming never worked reliably.

 

The 6i6 is from my partner who’s a classical musician and uses it to record rehearsals. But since it’s only used in that functionality about once a month and sounds better than the Airport Express we used so far it became our DAC in the study .

 

As a professional musician, I’ve used several USB audio interfaces meant for recording - my current piece is an M-Audio that has a 24/192 DAC in it the equal of “audiophile” units costing 10+ times as much (as does your Focusrite). The Focusrites are excellent and nothing for which to apologize. I’m 99+% sure they all work with all Linux variants as long as you’re using a current release - all current Linux with which I’m familiar are USB 2 compliant for music playback.

 

As I recall, there’s a volume control on outputs 1&2, so you can use fixed output from your player software & control volume with the knob on the 6i6.

 

But if you already have Ethernet where you want to put your player, you can use a Pi player with your NAS as the source - you don’t need the Mac at all. If the Mac is not being used for anything that requires it to be where it is now, you could move it to where you’d put the Pi, plug in the Ethernet cable, and drive the 6i6 directly from a USB port.

[mcgillroy]

Thx everybody! As for using the computer directly: this is a no-go as it's used as an office machine and hooked up to external monitor, printer and other periphery. Also it's about 7m from the desk to the stereo. An ethernet connection is in place and the NAS is in a different room.

 

I need to be able to play from both the NAS and the computer as the latter sometimes has more recent files. My NAS is superslow and a full-index after adding files takes hours.

 

As for the hardware. Having looked through the available offerings and a B3+ with PSU, case, card etc comes to about €75.-.

 

A Hifiberry DAC+ Pro complete bundle is €110.-

 

I am leaning towards the latter as it would free the Focusrite from this duty and also look cleaner. Not sure about the sound difference but I guess if it's significant I could still just relegate the Raspi to transport mode.

 

Any thoughts on the Hifiberry vs Focusrite and Hifiberry in general?

 

 

[bluesman]

2 hours ago, mcgillroy said:

Any thoughts on the Hifiberry vs Focusrite and Hifiberry in general?

 

I think Focusrite use the current Cirrus CS4272 chip, which is a one-piece ADC & DAC. It’s actually very good - full differential, 114 dB DR.  I think the Hifiberry uses a TI (BB) 5122, which is a bit more versatile (eg bit depth and sampling rate availability) but has similar performance specs with the same sources. Both are well designed circuits and you probably wouldn’t notice any difference in SQ.